Damage to the spine and pelvis in the practice of general practitioners and family medicine. Traumatic dislocation of the joints of upper and lower limbs, tendons and ligament damage to the machine at a family doctor. Diagnosis and first aid in outpatient family doctor. Features of the outpatient stage posthospital period. Drug-employment medical and social assessment. Providing emergency care for animal bites, electrical, drowning, of low and high temperatures.

 

Cervical Spine

EPIDEMIOLOGY

  • Cervical spine injuries usually occur secondary to high-energy mechanisms, including motor vehicle accident (45%) and falls from a height (20%).
  • Less commonly, cervical spine injuries occur during athletic participation (15%), most notably during American football and diving events, and as a result of acts of violence (15%).
  • Neurologic injury occurs in 40% of patients with cervical spine fractures.
  • Spinal cord damage is more frequently associated with lower rather than upper cervical spine fractures and dislocations.

ANATOMY

  • The atlas is the first cervical vertebra, which has no body. Its two large lateral masses provide the only two weight-bearing articulations between the skull and the vertebral column.
    • The tectoral membrane and the alar ligaments are the key to providing normal craniocervical stability.
    • The anterior tubercle is held adjacent to the odontoid process of C2 by the transverse atlantal ligament.
    • Fifty percent of total neck flexion and extension occurs at the occiput-C1 junction.
    • The vertebral artery emerges from the foramen transversarium and passes between C1 and the occiput, traversing a depression on the superior aspect of the C1 ring. Fractures are common in this location.
  • The axis is the second cervical vertebra, whose body is the largest of the cervical vertebrae.
    • The transverse atlantal ligament (cruciform ligament) provides primary support for the atlantoaxial joint.
    • The alar ligaments are secondary stabilizers of the atlantoaxial joint.
    • The facet joint capsules at occiput-C1 and C1-C2 provide little support.
    • Fifty percent of total neck rotation occurs at the C1-C2 junction.
  • C3-C7 can be conceptualized as a three-column system (Denis) (Fig. 1):
    • Anterior column: The anterior vertebral body and intervertebral disc resist compressive loads, while the anterior longitudinal ligament and annulus fibrosis are the most important checkreins to distractive forces (extension).
    • Middle column: The posterior vertebral body and uncovertebral joints resist compression, while the posterior longitudinal ligament and annulus fibrosis limit distraction.
    • Posterior column: The facet joints and lateral masses resist compressive forces, while the facet joint capsules, interspinous ligaments, and supraspinous ligaments counteract distractive forces.
    • The vertebral artery bypasses the empty foramen transversarium of C7 to enter the vertebral foramina of C6-C1. Injuries to the vertebral arteries are uncommon because of the redundancy of the vessel.

Figure 1. The components of the cervical three-column spine. The ligamentous complexes resist distractive forces. The bony structures counteract compression.

(From Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 4th ed, vol. 2. Philadelphia: Lippincott-Raven, 1996:1489.)

MECHANISM OF INJURY

  • Motor vehicle accidents (primarily in young patients), falls (primarily in older patients), diving accidents, and blunt trauma account for the majority of cervical spine injuries.
  • Forced flexion or extension resulting from unrestrained deceleration forces, with or without distraction or axial compression, is the mechanism for most cervical spine injuries.

Clinical Evaluation

  • Patient assessment is indicated: airway, breathing, circulation, disability, and exposure (ABCDE).
  • Initiate resuscitation: Address life-threatening injuries. Maintain rigid cervical immobilization.
  • Tracheal intubation and central line placement are often performed in the emergency setting. During intubation, manipulation of the neck can potentially displace unstable cervical fractures or dislocations. Manual in-line stabilization should be maintained throughout the intubation process. Alternatively, mask ventilation can be continued until fiberoptic or nasotracheal intubation can be safely performed. If an unstable spine is highly suspected, a cricothyroidotomy may be the safest alternative for airway control.
  • Evaluate the level of consciousness and neurologic impairment: Glasgow Coma Scale (see Chapter 2).
  • Assess head, neck, chest, abdominal, pelvic, extremity injury.
  • Ascertain the patientís history: mechanism of injury, witnessed head trauma, movement of extremities/level of consciousness immediately following trauma, etc.
  • Physical examination
    • Neck pain
    • Lacerations and contusions on scalp, face, or neck
  • Neurologic examination
    • Cranial nerves
    • Complete sensory and motor examination
    • Upper and lower extremity reflexes
    • Rectal examination: perianal sensation, rectal tone
    • Bulbocavernosus reflex (see Chapter 8)

Radiographic Evaluation

  • Lateral cervical spine radiograph: This will detect 85% of cervical spine injuries. One must visualize the atlantooccipital junction, all seven cervical vertebrae, and the cervicothoracic junction (as inferior as the superior aspect of T1). This may necessitate downward traction on both upper extremities or a swimmerís view (upper extremity proximal to the x-ray beam abducted 180 degrees, axial traction on the contralateral upper extremity, and the beam directed 60 degrees caudad). Patients complaining of neck pain should undergo complete radiographic evaluation of the cervical spine, including anteroposterior (AP) and odontoid views. On the lateral cervical spine radiograph, one may appreciate:
    • Acute kyphosis or loss of lordosis.
    • Continuity of radiographic ‚Äúlines‚ÄĚ: anterior vertebral line, posterior vertebral line, facet joint line, or spinous process line.
    • Widening or narrowing of disc spaces.
    • Increased distance between spinous processes or facet joints.
    • Abnormal retropharyngeal swelling, which depends on the level in question:
      • At C1: >10 mm
      • At C3, C4: >4 mm
      • At C5, C6, C7: >15 mm
    • Radiographic markers of cervical spine instability, including the following:
      • Compression fractures with >25% loss of height
      • Angular displacements >11 degrees between adjacent vertebrae (as measured by Cobb angle)
      • Translation >3.5 mm
      • Intervertebral disc space separation >1.7 mm (Figs. 2 and 3)
  • Computed tomography (CT) and/or magnetic resonance imaging (MRI) may be valuable to assess the upper cervical spine or the cervicothoracic junction, especially if it is inadequately visualized by plain radiography.
  • The proposed advantages of CT over a lateral cervical film as an initial screening tool are that it is more sensitive for detecting fractures and more consistently enables assessment of the occipitocervical and cervicothoracic junctions. A potential disadvantage of CT as an initial radiographic assessment is that subtle malalignment, facet joint gapping, or intervertebral distraction is difficult to assess using axial images alone.
  • The most useful applications of MRI are in detecting traumatic disc herniation, epidural hematoma, spinal cord edema or compression, and posterior ligamentous disruption. An additional application of MRI is the ability to visualize vascular structures.

MR arteriograms can be used to assess the patency of the vertebral arteries.

Figure 2. (A) Prevertebral soft tissue shadow. In a healthy recumbent adult without an endotracheal tube, the prevertebral soft tissue shadow should not exceed 6 mm. (B) Bony screening lines and dens angulation. The anterior cortex of the odontoid should parallel the posterior cortex of the anterior ring of the atlas. Any kyphotic or lordotic deviation should be viewed with suspicion for an odontoid fracture or transverse atlantal ligament disruption. Wackenheim line is drawn as a continuation from the clivus caudally. The tip of the odontoid should be within 1 to 2 mm of this line. The C1-C3 spinolaminar line’s reference points are drawn from the anterior cortex of the laminae of the atlas, axis, and C3 segments, which should fall within 2 mm of one another. Greater deviation should raise suspicion of atlantoaxial translation or disruption of the neural arches of either segment. (C) Ligamentous injury reference lines (lateral x-rays). The atlas-dens interval (ADI) should be less than 3 mm in an adult (5 mm in a child). The space available for the cord is measured as the distance from the posterior cortex of the odontoid tip to the anterior cortex of the posterior arch of the atlas and should amount to more than 13 mm. The dens-basion interval (DBI) is the distance between the odontoid tip and the distal end of the basion. It should be less than 12 mm in adults. The posterior axis line (PAL-B) should not be more than 4 mm anterior and should be less than 12 mm posterior to the basion. (D) Bony screening lines (anteroposterior imaging). The left and right lateral atlas-dens intervals (LADIs) should be symmetric to one another (with 2-mm deviation). The bony components of the atlantooccipital joints should be symmetric and should not be spaced more than 2 mm apart on anteroposterior images. (Courtesy of Fred Mann, MD, Professor of Radiology, University of Washington, Seattle.)

Figure 3. Radiographic indications of instability. Greater than 3.5 mm of translation (A) or 11 degrees of angulation (B) and widening of the separation between spinous processes are indications of instability on the lateral plain film.

(Adapted from Bucholz RW. Lower cervical spine injuries. In: Browner BD, Jupiter JB, Levine AM, et al. eds. Skeletal Trauma, vol. 1. Philadelphia: WB Saunders, 1992:707.)

  • Stress flexion/extension radiographs rarely if ever should be performed if instability is suspected; they should be performed in the awake and alert patient only. In a patient with neck pain, they are best delayed until spasm has subsided, which can mask instability. The atlantodens interval (ADI) should be <3 mm in adults and <5 mm in children.
  • Traction x-rays are taken during reductions only.

CLASSIFICATION

OTA Classification of Cervical Spine Injuries

See Fracture and Dislocation Compendium at http://www.ota.org/compendium/index.htm.

INJURIES TO THE OCCIPUT-C1-C2 COMPLEX

  • As with other transitional regions of the spine, the craniocervical junction is highly susceptible to injury. This regionís vulnerability to injury is particularly high because of the large lever-arm induced cranially by the skull and the relative freedom of movement of the craniocervical junction, which relies disproportionately on ligamentous structures rather than on intrinsic bony stability.

Occipital Condyle Fractures

  • These are frequently associated with C1 fractures as well as cranial nerve palsies.
  • The mechanism of injury involves compression and lateral bending; this causes either compression fracture of the condyle as it presses against the superior facet of C1 or avulsion of the alar ligament with extremes of atlantooccipital rotation.
  • CT is frequently necessary for diagnosis.

CLASSIFICATION (FIG. 4)

Figure 4. Anderson and Montesano classification of occipital condyle fractures. (A) Type I injuries are comminuted, usually stable, impaction fractures caused by axial loading. (B) Type II injuries are impaction or shear fractures extending into the base of the skull, and are usually stable. (C) Type III injuries are alar ligament avulsion fractures and are likely to be unstable distraction injuries of the craniocervical junction.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

Type I:

Impaction of condyle; usually stable

Type II:

Shear injury associated with basilar or skull fractures; potentially unstable

Type III:

Condylar avulsion; unstable

  • Treatment includes rigid cervical collar immobilization for 8 weeks for stable injuries and halo immobilization or occipital-cervical fusion for unstable injuries.
  • Craniocervical dissociation should be considered with any occipital condyle fracture.

Occipitoatlantal Dislocation (Craniovertebral Dissociation)

  • This is almost always fatal, with postmortem studies showing it to be the leading cause of death in motor vehicle accidents; rare survivors have severe neurologic deficits ranging from complete C1 flaccid quadriplegia to mixed incomplete syndromes such as Brown-Squard.
  • This is twice as common in children, owing to the inclination of the condyles.
  • It is associated with submental lacerations, mandibular fractures, and posterior pharyngeal wall lacerations.
  • It is associated with injury to the cranial nerves (the abducens and hypoglossal nerves are most commonly affected by craniocervical injuries), the first three cervical nerves, and the vertebral arteries.
  • The cervicomedullary syndromes, which include cruciate paralysis as described by Bell and hemiplegia cruciata initially described by Wallenberg, represent the more unusual forms of incomplete spinal cord injury and are a result of the specific anatomy of the spinal tracts at the junction of the brainstem and spinal cord. Cruciate paralysis can be similar to a central cord syndrome, although it normally affects proximal more than distal upper extremity function. Hemiplegia cruciata is associated with ipsilateral arm and contralateral leg weakness.
  • Mechanism is a high-energy injury resulting from a combination of hyperextension, distraction, and rotation at the craniocervical junction.
  • The diagnosis is often missed, but it may be made on the basis of the lateral cervical spine radiograph:
    • The tip of odontoid should be in line with the basion.
    • The odontoid-basion distance is 4 to 5 mm in adults and up to l0 mm in children.
    • Translation of the odontoid on the basion is never greater than 1 mm in flexion/extension views.
    • Powers ratio (BC/OA) should be <1 (Fig. 5).

Figure 5. Powers ratio.

(From Browner BD, Jupiter JB, Levine AM, et al. eds. Skeletal Trauma, vol. 1. Philadelphia: WB Saunders, 1992:668.)

    • In adults, widening of the prevertebral soft tissue mass in the upper neck is an important warning sign of significant underlying trauma and may be the only sign of this injury.
    • Fine-cut CT scans with slices no more than 2 mm wide are helpful to understand articular incongruities or complex fracture patterns more clearly. MRI of the craniovertebral junction is indicated for patients with spinal cord injury and can be helpful to assess upper cervical spine ligamentous injuries as well as subarachnoid and prevertebral hemorrhage.
  • Classification based on the position of the occiput in relation to C1 is as follows:

Type I:

Occipital condyles anterior to the atlas; most common

Type II:

Condyles longitudinally dissociated from atlas without translation; result of pure distraction

Type III:

Occipital condyles posterior to the atlas

  • The Harborview classification attempts to quantify stability of craniocervical junction. Surgical stabilization is reserved for type II and III injuries.

Type I:

Stable with displacement <2 mm

Type II:

Unstable with displacement <2 mm

Type III:

Gross instability with displacement >2 mm

  • Immediate treatment includes halo vest application with strict avoidance of traction. Reduction maneuvers are controversial and should ideally be undertaken with fluoroscopic visualization.
  • Long-term stabilization involves fusion between the occiput and the upper cervical spine.

Atlas Fractures

  • These are rarely associated with neurologic injury.
  • Instability invariably equates to the presence of transverse alar ligament insufficiency, which can be diagnosed either by direct means, such as by identifying bony avulsion on CT scan or ligament rupture on MRI, or indirectly by identifying widening of the lateral masses.
  • Fifty percent of these injuries are associated with other cervical spine fractures, especially odontoid fractures and spondylolisthesis of the axis.
  • Cranial nerve lesions of VI to XII and neurapraxia of the suboccipital and greater occipital nerves may be associated.
  • Vertebral artery injuries may cause symptoms of basilar insufficiency such as vertigo, blurred vision, and nystagmus.
  • Patients may present with neck pain and a subjective feeling of ‚Äúinstability.‚ÄĚ
  • The mechanism of injury is axial compression with elements of hyperextension and asymmetric loading of condyles causing variable fracture patterns.
  • Classification (Levine) (Fig. 6)
    • Isolated bony apophysis fracture
    • Isolated posterior arch fracture
    • Isolated anterior arch fracture
    • Comminuted lateral mass fracture
    • Burst fracture
  • Treatment

Figure 6. Classification of atlas fractures (according to Levine). (A) Isolated bony apophysis fracture. (B) Isolated posterior arch fracture. (C) Isolated anterior arch fracture. Comminuted lateral mass fracture (D) and burst fracture (E), three or more fragments.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

    • Initial treatment includes halo traction/immobilization.
    • Stable fractures (posterior arch or nondisplaced fractures involving the anterior and posterior portions of the ring) may be treated with a rigid cervical orthosis.
    • Less stable configurations (asymmetric lateral mass fracture with floating lateral mass, burst fractures) may require prolonged halo immobilization.
    • C1-C2 fusion may be necessary to alleviate chronic instability and/or pain.

Transverse Ligament Rupture (Traumatic C1-C2 Instability)

  • This rare, usually fatal injury, is seen mostly in older age groups (50s to 60s).
  • The mechanism of injury is forced flexion.
  • The clinical picture ranges from severe neck pain to complete neurologic compromise.
  • Rupture of the transverse ligament may be determined by:
    • Visualizing the avulsed lateral mass fragment on CT scan.
    • Atlantoaxial offset >6.9 mm on an odontoid radiograph.
    • ADI >3 mm in adults. An ADI >5 mm in adults also implies rupture of the alar ligaments.
    • Direct visualization of the rupture on MRI.
  • Treatment
    • Initial treatment includes halo traction/immobilization.
    • In the cases of avulsion, halo immobilization is continued until osseous healing is documented.
    • C1-C2 fusion is indicated for tears of the transverse ligament without bony avulsion, chronic instability, or pain (Fig. 7)
  •  

Figure 7. Axial CT image demonstrating transverse ligament rupture with atlanto-axial subluxation

(Reproduced with permission from Bucholz RW, Heckman JD, Court-Brown C, et al. eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams Wilkins, 2006.)

 

Atlantoaxial Rotary Subluxation and Dislocation

  • In this rare injury, patients present with confusing complaints of neck pain, occipital neuralgia, and, occasionally, symptoms of vertebrobasilar insufficiency. In chronic cases, the patient may present with torticollis.
  • It is infrequently associated with neurologic injury.
  • The mechanism of injury is flexion/extension with a rotational component, although in some cases it can occur spontaneously with no reported history of trauma.
  • Odontoid radiographs may show asymmetry of C1 lateral masses with unilateral facet joint narrowing or overlap (wink sign). The C2 spinous process may be rotated from the midline on an AP view.
  • The subluxation may be documented on dynamic CT scans; failure of C1 to reposition on a dynamic CT scan indicates fixed deformity.
  • Classification (Fielding)

Type I:

Odontoid as a pivot point; no neurologic injury; ADI <3 mm; transverse ligament intact (47%)

Type II:

Opposite facet as a pivot; ADI <5 mm; transverse ligament insufficient (30%)

Type III:

Both joints anteriorly subluxed; ADI >5 mm; transverse and alar ligaments incompetent

Type IV:

Rare; both joints posteriorly subluxed

Type V:

Levine and Edwards: frank dislocation; extremely rare

  • Treatment
    • Cervical halter traction in the supine position and active range-of-motion exercises for 24 to 48 hours initially are followed by ambulatory orthotic immobilization with active range-of-motion exercises until free motion returns.
    • Rarely, fixed rotation with continued symptoms and lack of motion indicates a C1-C2 posterior fusion

Fractures of the Odontoid Process (Dens)

  • A high association exists with other cervical spine fractures.
  • There is a 5% to10% incidence of neurologic involvement with presentation ranging from Brown-Squard syndrome to hemiparesis, cruciate paralysis, and quadriparesis.
  • Vascular supply arrives through the apex of the odontoid and through its base with a watershed area in the neck of the odontoid.
  • High-energy mechanisms of injury include motor vehicle accident or falls with avulsion of the apex of the dens by the alar ligament or lateral/oblique forces that cause fracture through the body and base of the dens.
  • Classification: (Anderson and DíAlonzo) (Fig. 8).

Type I:

Oblique avulsion fracture of the apex (5%)

Type II:

Fracture at the junction of the body and the neck; high nonunion rate, which can lead to myelopathy (60%)

Type IIA:

Highly unstable comminuted injury extending from the waist of the odontoid into the body of the axis

Type III:

Fracture extending into the cancellous body of C2 and possibly involving the lateral facets (30%)

  • Treatment

Type I:

If it is an isolated injury, stability of the fracture pattern allows for immobilization in a cervical orthosis.

Type II:

This is controversial, because the lack of periosteum and cancellous bone and the presence in watershed area result in a high incidence of nonunion (36%). Risk factors include age >50 years, >5 mm displacement, and posterior displacement. It may require screw fixation of the odontoid or C1-C2 posterior fusion for adequate treatment. Nonoperative treatment is halo immobilization.

Type III:

There is a high likelihood of union with halo immobilization owing to the cancellous bed of the fracture site.


Figure 8. The odontoid fracture classification of Anderson and D’Alonzo. (A) Type I fractures of the odontoid tip represent alar ligament avulsions. (B) Type II fractures occur at the odontoid waist, above the C2 lateral masses. (C) Type III fractures extend below the odontoid waist to involve the body and lateral masses of C2. Hadley has added the type IIA fracture with segmental comminution at the base of the odontoid (not shown)

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

C2 Lateral Mass Fractures

  • Patients often present with neck pain, limited range of motion, and no neurologic injury.
  • The mechanisms of injury are axial compression and lateral bending.
  • CT is helpful for diagnosis.
  • A depression fracture of the C2 articular surface is common.
  • Treatment ranges from collar immobilization to late fusion for chronic pain.

Traumatic Spondylolisthesis of C2 (Hangmanís Fracture)

  • This is associated with a 30% incidence of concomitant cervical spine fractures. It may be associated with cranial nerve, vertebral artery, and craniofacial injuries.
  • The incidence of spinal cord injury is low with types I and II and high with type III injuries.
  • The mechanism of injury includes motor vehicle accidents and falls with flexion, extension, and axial loads. This may be associated with varying degrees of intervertebral disc disruption. Hanging mechanisms involve hyperextension and distraction injury, in which the patient may experience bilateral pedicle fractures and complete disruption of disc and ligaments between C2 and C3.

Figure 9. Classification of traumatic spondylolisthesis of the axis (hangman’s fracture) (according to Effendi, modified by Levine). (A) Type I, nondisplaced fracture of the pars interarticularis. (B) Type II, displaced fracture of the pars interarticularis. (C) Type IIa, displaced fracture of the pars interarticularis with disruption of the C2-C3 discoligamentous complex. (D) Type III, dislocation of C2-C3 facets joints with fractured pars interarticularis

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • Classification (Levine and Edwards; Effendi) (Fig. 9)

Type I:

Nondisplaced, no angulation; translation <3 mm; C2-C3 disc intact (29%); relatively stable

Type Ia:

Atypical unstable lateral bending fractures that are obliquely displaced and usually involve only one pars interarticularis, extending anterior to the pars and into the body on the contralateral side

Type II:

Significant angulation at C2-C3; translation >3 mm; most common injury pattern; unstable; C2-C3 disc disrupted (56%); subclassified into flexion, extension, and listhetic types

Type IIA:

Avulsion of entire C2-C3 intervertebral disc in flexion with injury to posterior longitudinal ligament, leaving the anterior longitudinal ligament intact; results in severe angulation; no translation; unstable; probably caused by flexion-distraction injury (6%); traction contraindicated

Type III:

Rare; results from initial anterior facet dislocation of C2 on C3 followed by extension injury fracturing the neural arch; results in severe angulation and translation with unilateral or bilateral facet dislocation of C2-C3; unstable (9%); type III injuries most commonly associated with spinal cord injury

  • Treatment

Type I:

This usually requires rigid cervical orthosis for up to 6 weeks.

Type II:

This is determined by stability; it usually requires halo traction/immobilization with serial radiographic confirmation of reduction for at least 6 weeks.

Type IIA:

Traction may exacerbate the condition; therefore, only immobilization may be indicated.

Type III:

Initial halo traction is followed by open reduction and posterior fusion of C2-C3, with possible anterior fusion.

 

INJURIES TO C3-C7

  • Vertebral bodies have a superior cortical surface that is concave in the coronal plane and convex in the sagittal plane, allowing for flexion, extension, and lateral tilt by the gliding motion of the facets.
  • The uncinate process projects superiorly from the lateral aspect of the vertebral body. With degenerative changes, these may articulate with the superior vertebra, resulting in an uncovertebral joint (of Luschka).
  • The mechanism of injury includes motor vehicle accidents, falls, diving accidents, and blunt trauma.
  • Radiographic evaluation consists of AP, lateral, and odontoid views of the cervical spine, as described earlier in the section on radiographic evaluation of cervical spine instability).
    • If cervical spine instability is suspected, flexion/extension views may be obtained in a willing, conscious, and cooperative patient without neurologic compromise. A stretch test (Panjabi and White) may be performed with longitudinal cervical traction. An abnormal test is indicated by a greater than 1.7-mm interspace separation or a >7.5-degree change between vertebrae.
    • CT scans with reconstructions may be obtained to characterize fracture pattern and degree of canal compromise more clearly.
    • MRI may be undertaken to delineate spinal cord, disc, and canal abnormalities further.
    • The amount of normal cervical motion at each level has been extensively described, and this knowledge can be important in assessing spinal stability after treatment. Flexion-extension motion is greatest at the C4-5 and C5-6 segments, averaging about 20 degrees. Axial rotation ranges from 2 to 7 degrees at each of the subaxial motion segments; the majority (45% to 50%) of rotation occurs at the C1-C2 articulation. Lateral flexion is 10 to 11 degrees per level in the upper segments (C2-5). Lateral motion decreases caudally, with only 2 degrees observed at the cervicothoracic junction.

 

Classification (Allen-Ferguson) (Fig. 10)

Figure 10. The five stages of compression flexion injuries.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

         Compressive flexion (shear mechanism resulting in teardrops fractures)

Stage I:

Blunting of anterior body; posterior elements intact

Stage II:

Beaking of the anterior body; loss of anterior vertebral height

Stage III:

Fracture line passing from anterior body through the inferior subchondral plate

Stage IV:

Inferoposterior margin displaced <3 mm into the neural canal

Stage V:

Teardrop fracture; inferoposterior margin >3 mm into the neural canal; failure of the posterior ligaments and the posterior longitudinal ligament

         Vertical compression (burst fractures) (Fig. 11)

Stage I:

Fracture through the superior or inferior endplate with no displacement

Stage II:

Fracture through both endplates with minimal displacement

Stage III:

Burst fracture; displacement of fragments peripherally and into the neural canal

 

Figure 11. The three stages of vertical compression injuries.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

         Distractive flexion (dislocations) (Fig. 12)

Stage I:

Failure of the posterior ligaments, divergence of the spinous processes, and facet subluxation

Stage II:

Unilateral facet dislocation; translation always <50%

Stage III:

Bilateral facet dislocation; translation of 50% and perched facets

Stage IV:

Bilateral facet dislocation with 100% translation

 

 

Figure 12. The four stages of distraction flexion injuries.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

Compressive extension (Fig. 13)

Stage I:

Unilateral vertebral arch fracture

Stage II:

Bilateral laminar fracture without other tissue failure

Stages III, IV:

Theoretic continuum between stages II and V

Stage V:

Bilateral vertebral arch fracture with full vertebral body displacement anteriorly; ligamentous failure at the posterosuperior and anteroinferior margins

 

Figure 13. The five stages of compression extension injuries.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Distractive extension (Fig. 14)

 

Stage I:

Failure of anterior ligamentous complex or transverse fracture of the body; widening of the disc space and no posterior displacement

Stage II:

Failure of posterior ligament complex and superior displacement of the body into the canal

Figure 14. (A and B) The two stages of distraction extension injuries.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

Lateral flexion (Fig. 15)

Stage I:

Asymmetric, unilateral compression fracture of the vertebral body plus a vertebral arch fracture on the ipsilateral side without displacement

Stage II:

Displacement of the arch on the AP view or failure of the ligaments on the contralateral side with articular process separation


         Miscellaneous cervical spine fractures

Figure 15. Lateral flexion injuries. Blunt trauma from the side places the ipsilateral spine in distraction while compressing the contralateral spine. (A) Stage I injury, asymmetric centrum fracture with a unilateral arch fracture. (B) Stage II injury, with displacement of the body and contralateral ligamentous failure.

(Adapted from Rizzolo SJ, Cotler JM. Unstable cervical spine injuries: specific treatment approaches. J Am Acad Orthop Surg 1993;1:5766.)

o    Clay shovelers fracture: This is an avulsion of the spinous processes of the lower cervical and upper thoracic vertebrae. Historically, this resulted from muscular avulsion during shoveling in unyielding clay with force transmission through the contracted shoulder girdle. Treatment includes restricted motion and symptomatic treatment until clinical improvement or radiographic healing of the spinous process occurs.

o    Sentinel fracture: This fracture occurs through the lamina on either side of the spinous process. A loose posterior element may impinge on the cord. Symptomatic treatment only is indicated unless spinal cord compromise exists.

o    Ankylosing spondylitis: This may result in calcification and ossification of the ligamentous structures of the spine, producing chalk stick fractures after trivial injuries. These fractures are notoriously unstable because they tend to occur through brittle ligamentous structures. Treatment includes traction with minimal weight in flexion, with aggressive immobilization with either halo vest or open stabilization.

Gunshot injuries: Missile impact against bony elements may cause high-velocity fragmentation frequently associated with gross instability and complete spinal cord injury. Surgical extraction of missile fragments is rarely indicated in the absence of canal compromise. Missiles that traverse the esophagus or pharynx should be removed, with aggressive exposure and debridement of the missile tract. These injuries carry high incidences of abscess formation, osteomyelitis, and mediastinitis.

TREATMENT: GENERAL CERVICAL SPINE

 

Initial Treatment

  • Immobilization with a cervical orthosis (for stable fractures) or Gardner-Wells tong traction (for unstable injuries) should be maintained in the emergency setting before CT for evaluation of spinal and other system injuries.
  • Vasopressor support is indicated for suspected neurogenic shock and emergency assessment for potential intracranial trauma.
  • Patients with neurologic injuries should be considered for intravenous methylprednisolone per the NASCIS II and III protocol (30 mg/kg loading dose and then 5.4 mg/kg for 24 hours if started within 3 hours, for 48 hours if started within 8 hours. Steroids have no benefit if they are started more than 8 hours after injury).
  • The majority of cervical spine fractures can be treated nonoperatively. The most common method of nonoperative treatment is immobilization in a cervical orthosis. In reality, orthoses decrease motion rather than effect true immobilization. Motion at the occipital-cervical junction is slightly increased by most cervical collars.
    • Soft cervical orthosis: This produces no significant immobilization and is a supportive treatment for minor injuries.
    • Rigid cervical orthosis (Philadelphia collar): This is effective in controlling flexion and extension; however, it provides little rotational or lateral bending stability.
    • Poster braces: These are effective in controlling midcervical flexion, with fair control in other planes of motion.
    • Cervicothoracic orthoses: These are effective in flexion and extension and rotational control, with limited control of lateral bending.
    • Halo device: This provides the most rigid immobilization (of external devices) in all planes.
    • For traction, Gardner-Wells tongs are applied one fingers width above the pinna of the ear in line with the external auditory canal. Slight anterior displacement will apply an extension force, whereas posterior displacement will apply a flexion force, useful when reducing facet dislocations (Fig. 16).
    • Numerous complications are associated with use of cervical collars. Skin breakdown at bony prominences, in particular the occiput, mandible, and sternum can occur. Up to 38 percent of patients with severe closed head injuries can develop skin complications with prolonged use.
  • Patients with neural deficits from burst-type injuries: Traction is used to stabilize and indirectly decompress the canal via ligamentotaxis.
  • Patients with unilateral or bilateral facet dislocations and complete neural deficits: Gardner-Wells tong traction and reduction by sequentially increasing the amount of traction are indicated.
  • Traction is contraindicated in distractive cervical spine injuries and type IIA spondylolisthesis injuries of C2.
  • Patients with incomplete neural deficits or who are neurologically intact with unilateral and bilateral facet dislocations require MRI before reduction via traction to evaluate for a herniated disc, especially if a patient is not awake and alert and able to cooperate with serial examinations during reduction maneuvers.

Figure 16. Closed reduction technique. Diagram of cranial tong technique for maintaining alignment and stability of the spine. Weight is increased gradually with a maximum of 45 to 50 lb (10 lb for the head and 5 lb for each successive interspace). Patients with an unrevealing examination may require a magnetic resonance imaging scan before reduction to rule out a space-occupying lesion in the vertebral canal. Failure of reduction may also necessitate such a scan.

(Adapted from Bucholz RW. Lower cervical spine injuries. In: Browner BD, Jupiter JB, Levine AM, et al., eds. Skeletal Trauma, vol. 1. Philadelphia: WB Saunders, 1992:638.)

  • A halo has been recommended for patients with isolated occipital condyle fractures, unstable atlas ring fractures, odontoid fractures, and displaced neural arch fractures of the axis.
  • The halo vest relies on a tight fit of the vest around the torso and is poorly tolerated by elderly patients and patients with pulmonary compromise or thoracic deformities, such as those with ankylosing spondylitis.
  • The halo ring should be applied 1 cm above the ears. Anterior pin sites should be placed below the equator of the skull above the supraorbital ridge, anterior to the temporalis muscle, and over the lateral two-thirds of the orbit. Posterior sites are variable and are placed to maintain horizontal orientation of the halo. Pin pressure should be 6 to 8 lb in the adult and should be tightened at 48 hours and monthly thereafter. Pin care is essential.
  • Prolonged recumbence carries an increased morbidity and mortality risk, and consideration should be given to the use of a RotoRest bed and mechanical as well as pharmacologic thromboprophylaxis.
  • Because of the normally wide spinal canal diameter, decompression of neural elements in upper cervical spine fractures is not commonly required for traumatic conditions.
  • The optimal time to perform surgery, particularly in patients with neurologic deficits, remains unclear. The two most commonly proposed benefits of earlier versus later surgery are improved rates of neurologic recovery and improved ability to mobilize the patient without concern of spinal displacement. To date, little human clinical evidence supports the view that early surgical decompression and stabilization improve neurologic recovery rates. However, clinical series have demonstrated that surgery performed as soon as 8 hours after injury does not appear to increase the rate of complications or lead to neurologic decline.

Stabilization of the Upper Cervical Spine (Occiput-C2)

  • The mainstay of operative treatment of upper cervical fractures and dislocations remains fusion with instrumentation, most commonly performed from the posterior approach. In order of frequency, the most common upper cervical fusion procedures are atlantoaxial fusion, occipitocervical fusion, and least commonly, C1-C3 fusion.
  • Fusion of the occiput-C1 limits 50% of flexion and extension.
  • Fusion of C1-C2 limits 50% of rotation.

Anterior Approach

There are three main indications for anterior upper cervical spine exposure in trauma.

  • Screw fixation of a type II odontoid fracture
  • Anterior interbody fusion and plating of the C2-3 interspace for a type IIA or III hangman‚Äôs fracture
  • Anterior arthrodesis of the atlantoaxial articulations as a rare salvage procedure for failed posterior atlantoaxial fusion at-tempts

Posterior Approach

Most upper cervical fractures are treated through a posterior approach.

  • Modified Brooks or Gallie arthrodesis uses sublaminar wires and a bone graft between the arches of C1 and C2.
    • Flexion control is obtained via the wires, extension via the bone blocks, and rotation via friction between the bone blocks and the posterior arches.
  • Transarticular screws are effective, especially if the posterior elements of C1 and C2 are fractured.

Osteosynthesis

  • The two indications for direct fracture repair in the upper cervical spine involve the treatment of type II odontoid fractures or type II traumatic spondylolistheses of C2 with interfragmentary screw fixation.
  • This is not indicated for fixation of anteriorly displaced odontoid fractures.

Stabilization of the Lower Cervical Spine (C3-C7)

  • Fifty percent of flexion/extension and 50% of rotation are evenly divided between each of the facet articulations.
  • Fusion of each level reduces motion by a proportionate amount.
  • Posterior decompression and fusion:
    • The posterior approach to the cervical spine is a midline, extensile approach that can be used to access as many spinal levels as necessary, with a variety of instrumentation techniques in use.
    • In the majority of acute, traumatic, subaxial spinal injuries, posterior decompression via laminectomy is not necessary. Canal compromise is most frequently caused by dislocation, translation, or retropulsed vertebral body fragments. In rare cases of anteriorly displaced posterior arch fragments, laminectomy would be indicated to directly remove the offending compressive elements. This is not true, however, in cases of acute spinal cord injury associated with multilevel spondylotic stenosis or ossification of the posterior longitudinal ligament, in which a posterior decompressive procedure may be considered the procedure of choice if cervical lordosis has been maintained.
    • Open reduction of dislocated facet joints is typically performed using a posterior approach.
  • Bilateral lateral mass plating
    • This can be utilized for a variety of fractures including facet fractures, facet dislocations, and teardrop (compressive flexion stage V) fractures.
    • Single-level fusions are sufficient for dislocations, although multilevel fusions may be required for more unstable patterns.
    • This can stop fusion at levels with fractured spinous processes or laminae, thus avoiding the fusion of extra levels with consequent loss of motion.
  • Anterior decompression and fusion
    • These are used for vertebral body burst fractures with spinal cord injury and persistent anterior cord compression.
    • The anterior approach to the subaxial spine utilizes the interval plane between the sternocleidomastoid (lateral) and anterior strap (medial) muscles. Deeper, the interval of dissection is between the carotid sheath laterally and the trachea/esophagus medially.
    • MRI, myelography, and CT are valuable in preoperative assessment of bony and soft tissue impingement on the spinal cord.
    • A simple discectomy or corpectomy in which osseous fragments are removed from the canal and a tricortical iliac or fibular graft placed between the vertebral bodies by a variety of techniques can be performed.
    • In the presence of a herniated cervical disc associated with dislocated facet joints, one may elect to perform an anterior discectomy and decompression before facet reduction.
    • Anterior plating or halo vest immobilization adds stability during healing.

COMPLICATIONS

Complications of spinal cord injury are covered in Chapter 8.

 

 

Fractures of the Thoracic and Lumbar Spine

 

Thoracolumbar Spine

EPIDEMIOLOGY

  • Neurologic injury complicates 15% to 20% of fracture at the thoracolumbar level.
  • Sixty-five percent of thoracolumbar fractures occur as a result of motor vehicle trauma or fall from a height, with the remainder caused by athletic participation and assault.
  • Recent data have indicated that motorcycle accidents are associated with a greater chance of severe and multiple level spinal column injuries than other types of vehicular trauma.

ANATOMY

See Chapter 8 for a general definition of terms.

  • The thoracolumbar spine consists of 12 thoracic vertebrae and 5 lumbar vertebrae.
  • The thoracic level is kyphotic, the lumbar region lordotic. The thoracolumbar region, as a transition zone, is especially prone to injury.
  • The thoracic spine is much stiffer than the lumbar spine in flexion-extension and lateral bending, reflecting the restraining effect of the rib cage as well as the thinner intervertebral discs of the thoracic spine.
  • Rotation is greater in the thoracic spine, achieving a maximum at T8-T9. The reason is the orientation of the lumbar facets, which limit the rotation arc to approximately 10 degrees for the lumbar spine versus 75 degrees for the thoracic spine.
  • The conus medullaris is found at the L1-L2 level. Caudal to this is the cauda equina, which comprises the motor and sensory roots of the lumbosacral myelomeres (Fig. 17).
  • The corticospinal tracts demonstrate polarity, with cervical fibers distributed centrally and sacral fibers peripherally.
  • The ratio of the spinal canal dimensions to the spinal cord dimensions is smallest in the T2-T10 region, which makes this area prone to neurologic injury after trauma.
  • Neurologic deficits secondary to skeletal injury from the first through the tenth thoracic levels are frequently complete deficits, primarily related to spinal cord injury with varying levels of root injury. The proportion of root injury increases with more caudal injuries, with skeletal injuries caudal to L1 causing entirely root injury.
  • The region between T2 and T10 is a circulatory watershed area, deriving its proximal blood supply from antegrade vessels in the upper thoracic spine and distally from retrograde flow from the artery of Adamkiewicz, which can be variably located between T9 to L2.
  • Most thoracic and lumbar injuries occur within the region between T11 and L1, commonly referred to as the thoracolumbar junction. This increased susceptibility can be explained by a variety of factors. The thoracolumbar junction is a transition zone between the relatively stiff thoracic spine and the more mobile lumbar spine.

Figure 17. The relationship between myelomeres (spinal cord segments) and the vertebral bodies.

(From Benson DR, Keenen TL. Evaluation and treatment of trauma to the vertebral column. Instr Course Lect 1990;39:577.)


MECHANISM OF INJURY

  • These generally represent high-energy injuries, typically from motor vehicle accident or falls from a height.
  • They may represent a combination of flexion, extension, compression, distraction, torsion, and shear.

CLINICAL EVALUATION

  • Patient assessment: This involves airway, breathing, circulation, disability, and exposure (ABCDE).
  • Initiate resuscitation: Address life-threatening injuries. Maintain spine immobilization. Watch for neurogenic shock (hypotension and bradycardia).
  • Evaluate the level of consciousness and neurologic impairment: Glasgow Coma Scale.
  • Assess head, neck, chest, abdominal, pelvic, extremity injury.
  • Ascertain the history: mechanism of injury, witnessed head trauma, movement of extremities/level of consciousness immediately following trauma, etc.
  • Physical examination
    • Back pain and tenderness
    • Lacerations, abrasions and contusions on back
    • Abdominal and/or chest ecchymosis from seat belt injury (also suggestive of liver, spleen or other abdominal injury)
  • Neurologic examination
    • Cranial nerves
    • Complete motor and sensory examination (Figs. 18 and 19)
    • Upper and lower extremity reflexes

Figure 18. A screening examination of the lower extremities assesses the motor function of the lumbar and first sacral nerve roots: hip adductors, L1-L2; knee extension, L3-L4; knee flexion, L5-S1; great toe extension, L5; and great toe flexion, S1.

(From Benson DR, Keenen TL. Evaluation and treatment of trauma to the vertebral column. Instr Course Lect 1990;39:583.)

Figure 19. A pain and temperature dermatome chart. These sensory modalities are mediated by the lateral spinothalamic tract. Note that C4 includes the upper chest just superior to T2. The rest of the cervical and T1 roots are located in the upper extremities. There is overlap in the territories subserved by each sensory root and variation among individuals.

(From Benson DR, Keenen TL. Evaluation and treatment of trauma to the vertebral column. Instr Course Lect 1990;39:584.)

    • Rectal examination: perianal sensation, rectal tone (Fig. 20)
    • Bulbocavernosus reflex (Fig. 21)
  • In the alert and cooperative patient, the thoracic and lumbar spine can be ‚Äúcleared‚ÄĚ with the absence of pain or tenderness or distraction mechanism of injury and a normal neurologic examination. Otherwise, imaging is required.

Figure 20. Sacral sparing may include the triad of perianal sensation, rectal tone, and great toe flexion.

(From Benson DR, Keenen TL. Evaluation and treatment of trauma to the vertebral column. Instr Course Lect 1990;39:580.)

Figure 21. The bulbocavernosus reflex arc is mediated by the conus medullaris and the lower three sacral roots. Stimulation of the glans penis, glans clitoris, or gentle traction on a Foley catheter to stimulate the bladder will evoke contraction of the rectal sphincter.

(From Benson DR, Keenen TL. Evaluation and treatment of trauma to the vertebral column. Instr Course Lect 1990;39:578.)


RADIOGRAPHIC EVALUATION

  • Anteroposterior (AP) and lateral views of the thoracic and lumbar spine are obtained.
  • Abnormal widening of the interpedicular distance signifies lateral displacement of vertebral body fragments, typical of burst fractures.
  • Vertebral body height loss can be measured by comparing the height of the injured level with adjacent uninjured vertebrae
  • Quantification of sagittal plane alignment can be performed using the Cobb method.
  • Chest and abdominal radiographs obtained during the initial trauma survey are not adequate for assessing vertebral column injury.
  • Computed tomography (CT) and/or magnetic resonance imaging of the injured area may be obtained to characterize the fracture further, to assess for canal compromise, and to evaluate the degree of neural compression.
  • CT scans provide finer detail of the bony involvement in thoracolumbar injuries, and MRI can be used to evaluate for soft tissue injury to the cord, intervertebral discs or for posterior ligamentous disruption.

CLASSIFICATION

 

OTA Classification of Thoracic and Lumbar Spine Injuries

See Fracture and Dislocation Compendium at http://www.ota.org/compendium/index.htm.

McAfee et al.

 

Classification is based on the failure mode of the middle osteoligamentous complex (posterior longitudinal ligament, posterior half of vertebral body and posterior annulus fibrosus)

  • Axial compression
  • Axial distraction
  • Translation within the transverse plane

This led to the following six injury patterns in this classification:

  • Wedge-compression fracture.
  • Stable burst fracture.
  • Unstable burst fracture.
  • Chance fracture.
  • Flexion-distraction injury.
  • Translational injuries.

McCormack et al.

  • This is a load-sharing classification.
  • A point value is assigned to the degree of vertebral body comminution, fracture fragment apposition, and kyphosis. Based on their primary outcome of hardware failure, McCormack et al. concluded that injuries with scores greater than 6 points would be better treated with the addition of anterior column reconstruction to posterior stabilization. A recent study demonstrated very high interobserver and intraobserver reliability of this classification system.

Denis

Minor Spinal Injuries

  • Articular process fractures (1%)
  • Transverse process fractures (14%)
  • Spinous process fractures (2%)
  • Pars interarticularis fractures (1%)

Major Spinal Injuries

  • Compression fractures (48%)
  • Burst fractures (14%)
  • Fracture-dislocations (16%)
  • Seat belt type injuries (5%)
  • Compression fractures
    • These can be anterior (89%) or lateral (11%).
    • They are rarely associated with neurologic compromise.
    • They are generally stable injuries, although they are considered unstable if associated with loss of >50% vertebral body height, angulation >20 to 30 degrees, or multiple adjacent compression fractures.
    • The middle column remains intact; it may act as a hinge with a posterior column distraction injury (seen with compression in 40% to 50%).
    • Four subtypes are described based on endplate involvement (Fig. 22):

Type A:

Fracture of both endplates (16%)

Type B:

Fracture of superior endplate (62%)

Type C:

Fracture of inferior endplate (6%)

Type D:

Both endplates intact (15%)

 

Figure 22. Compression fractures.

(From Browner BD, Jupiter JD, Levine MA, eds. Skeletal Trauma. Philadelphia: WB Saunders, 1992:746.)

    • Treatment includes an extension orthosis (Jewett brace or thoracolumbar spinal orthosis) with early ambulation for most fractures, which are stable. Unstable fractures (>50% height loss or 20 to 30 degrees of kyphosis in nonosteoporotic bone strongly suggests the possibility of posterior ligament complex disruption, which places the patient at risk of increasing kyphotic deformity or neurologic deficit) may require hyperextension casting or open reduction and internal fixation. Upper thoracic fractures are not amenable to casting or bracing and require surgical management to prevent significant kyphosis.
  • Burst fractures
    • No direct relationship exists between the percentage of canal compromise and the degree of neurologic injury.
    • The mechanism is compression failure of the anterior and middle columns under an axial load.
    • An association between lumbar burst fractures, longitudinal laminar fractures, and neurologic injury.
    • These injuries result in loss of posterior vertebral body height and splaying of pedicles on radiographic evaluation.
    • Five types are recognized (Fig. 23):

Type A:

Fracture of both endplates (24%)

Type B:

Fracture of the superior endplate (49%)

Type C:

Fracture of inferior endplate (7%)

Type D:

Burst rotation (15%)

Type E:

Burst lateral flexion (5%)

 

 

Figure 23. Denis classification of burst fractures. Type A involves fractures of both endplates, type B involves fractures of the superior endplate, and type C involves fractures of the inferior endplate. Type D is a combination of a type A fracture with rotation. Type E fractures exhibit lateral translation.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

    • Treatment may consist of hyperextension casting if no neurologic compromise exists and the fracture pattern is stable (see compression fractures, earlier).
    • Early stabilization is advocated to restore sagittal and coronal plane alignment in cases with:
      • Neurologic deficits.
      • Loss of vertebral body height >50%.
      • Angulation >20 to 30 degrees.
      • Canal compromise of >50%.
      • Scoliosis >10 degrees.
    • Anterior, posterior, and combined approaches have been used.
    • Posterior surgery relies on indirect decompression via ligamentotaxis and avoids the morbidity of anterior exposure in patients who have concomitant pulmonary or abdominal injuries; it also has shorter operative times and decreased blood loss. Anterior approaches allow for direct decompression. Posterior instrumentation alone cannot directly reconstitute anterior column support and is therefore somewhat weaker in compression than anterior instrumentation. This has lead to a higher incidence of progressive kyphosis and instrumentation failure when treating highly comminuted fractures.
    • Instrumentation should provide distraction and extension moments.
    • Harrington rods tend to produce kyphosis and are thus contraindicated for use in the lower lumbar spine.
    • Laminectomies should not be done without instrument stabilization.
  • Flexion-distraction injuries (Chance fractures, seat belt type injuries).
    • Patients are usually neurologically intact.
    • Up to 50% may have associated abdominal injuries.
    • Flexion-distraction injury results in compression failure of the anterior column and tension failure of the posterior and middle columns.
    • Injuries rarely occur through bone alone and are most commonly the result of osseous and ligamentous failure. (Fig. 24).

Figure 24. Flexion-distraction injuries. The bony Chance fracture (A) is often associated with lap seat-belt use. This fracture was originally described by Bohler years before Chance. A flexiondistraction injury can occur entirely through soft tissue (B).

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

    • One may see increased interspinous distance on the AP and lateral views.
    • Four types are recognized:

Type A:

One-level bony injury (47%)

Type B:

One-level ligamentous injury (11%)

Type C:

Two-level injury through bony middle column (26%)

Type D:

Two-level injury through ligamentous middle column (16%)

    • Treatment consists of hyperextension casting for type A injuries.
    • For injuries with compromise of the middle and posterior columns with ligamentous disruption (types B,C,D), posterior spinal fusion with compression should be performed.
    • The primary goal of surgery for flexion-distraction injuries is not to reverse neurologic deficit, but to restore alignment and stability to enable early patient mobilization and to prevent secondary displacement.
  • Unless a herniated disc is noted on a preoperative MRI and warrants anterior discectomy, posterior reduction and compressive stabilization of the involved segment are usually adequate.
  • Fracture dislocations
    • All three columns fail under compression, tension, rotation, or shear, with translational deformity.
    • Three types, with different mechanisms (Denis), are known, as follows:

Type A:

Flexion-rotation: posterior and middle column fail in tension and rotation; anterior column fails in compression and rotation; 75% with neurologic deficits, 52% of these being complete lesions (Fig. 25)

Type B:

Shear: shear failure of all three columns, most commonly in the posteroanterior direction; all cases with complete neurologic deficit (Fig. 26)

Type C:

Flexion-distraction: tension failure of posterior and middle columns, with anterior tear of annulus fibrosus and stripping of the anterior longitudinal ligament; 75% with neurologic deficits (all incomplete) (Fig. 27)

Figure 25. A flexion-rotation type of fracture-dislocation.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

Figure 26. A posteroanterior (A) shear-type fracture-dislocation. An anteroposterior (B) shear-type fracture-dislocation. This nomenclature is based on the direction of the shear force that would produce the injury when applied to the superior vertebra.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

    • Generally, these are highly unstable injuries that require surgical stabilization.
    • Posterior surgery is usually most useful for achieving reduction and stability in these injuries.
    • The characteristic deformity of fracture-dislocations is translational malalignment of the involved vertebrae. Realigning the spine is often difficult and is best performed by direct manipulation of the vertebra with bone clamps or elevators. Gradual distraction may be needed to reduce dislocations with no associated fracture.
    • Patients whose fractures are stabilized within 3 days of injury have a lower incidence of pneumonia and a shorter hospital stay than those with fractures stabilized more than 3 days after injury.
    • Patients without neurologic deficit do not typically need urgent surgery. Surgery can be performed when the patient has been adequately stabilized medically. A similar approach should be employed in patients that have complete neurologic injuries when there is little chance for significant recovery.

Figure 27. A flexion distraction type of dislocation.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

 

SPINAL STABILITY

A spinal injury is considered unstable if normal physiologic loads cause further neurologic damage, chronic pain, and unacceptable deformity.

White and Panjabi

Defined scoring criteria have been developed for the assessment of clinical instability of spine fractures (Tables 1 and 2).

Table 1. Thoracic and thoracolumbar spine stability scale

Element

Point Value

Anterior elements unable to function

2

Posterior elements unable to function

2

Disruptions of costovertebral articulations

1

Radiographic criteria

4

Sagittal displacement >2.5 mm (2 pts)

 

Relative sagittal plane angulation >5 degrees (2 pts)

 

Spinal cord or cauda equina damage

2

Dangerous loading anticipated

1

Instability: total of ‚Č•5 points.
From White A, Punjabi M. Clinical Biomechanics of the Spine. Philadelphia: JB Lippincott, 1990:335.

Table 2. Lumbar spine stability scale

Element

Point Value

Anterior elements unable to function

2

Posterior elements unable to function

2

Radiographic criteria

4

Flexion/extension x-rays

 

Sagittal plane translation >4.5 mm or 15% (2 pts)

Sagittal plane rotation (2 pts)

>15 degrees at L1-2, L2-3, and L3-4

>20 degrees at L4-5

>25 degrees at L5-S1

OR

Resting x-rays

Sagittal plane displacement >4.5 mm or 15% (2 pts)

Relative sagittal plane angulation >22 degrees (2 pts)

Spinal cord or cauda equina damage

2

Cauda equina damage

3

Dangerous loading anticipated

1

Instability: total of ‚Č•5 points.
From White A, Punjabi M. Clinical Biomechanics of the Spine. Philadelphia: JB Lippincott, 1990:335.

Denis

The three-column model of spinal stability (Fig. 28 and Table 3) is as follows:

Table 3. Basic types of spinal fractures and columns involved in each

Type of Fracture

Column Involvement

Anterior

Middle

Posterior

Compression

Compression

None

None or distraction (in severe fractures)

Burst

Compression

Compression

None or distraction

Seat belt

None or compression

Distraction

Distraction

Fracture-dislocation

Compression and/or anterior rotation, shear

Distraction and/or rotation, shear

Distraction and/or rotation, shear

From Denis F. The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 1983;8:817831.

  • Anterior column: anterior longitudinal ligament, anterior half of the vertebral body, and anterior annulus
  • Middle column: posterior half of vertebral body, posterior annulus, and posterior longitudinal ligament
  • Posterior column: posterior neural arches (pedicles, facets, and laminae, and posterior ligamentous complex (supraspinous ligament, interspinous ligament, ligamentum flavum, and facet capsules)

 

Figure 28. The three columns of the spine, as proposed by Francis Denis. The anterior column (A) consists of the anterior longitudinal ligament, anterior part of the vertebral body, and the anterior portion of the annulus fibrosis. The middle column (B) consists of the posterior longitudinal ligament, posterior part of the vertebral body, and posterior portion of the annulus. The posterior column (C) consists of the bony and ligamentous posterior elements.

(Modified from Denis F. The three-column spine and its significance in the classification of acute thoracolumbar spine injuries. Spine 1983;8:817831.)

  • Instability exists with disruption of any two of the three columns
  • Thoracolumbar stability usually follows the middle column: if it is intact, then the injury is usually stable.

Three degrees of instability are recognized:

  • First degree (mechanical instability): potential for late kyphosis
    • Severe compression fractures
    • Seat belt type injuries
  • Second degree (neurologic instability): potential for late neurologic injury
    • Burst fractures without neurologic deficit
  • Third degree (mechanical and neurologic instability)
    • Fracture-dislocations
    • Severe burst fractures with neurologic deficit

McAfee

This author noted that burst fractures can be unstable, with early progression of neurologic deficits and spinal deformity as well as late onset of neurologic deficits and mechanical back pain.

  • Factors indicative of instability in burst fractures:
    • >50% canal compromise
    • >15 to 25 degrees of kyphosis
    • >40% loss of anterior body height

GUNSHOT WOUNDS

  • In general, fractures associated with low-velocity gunshot wounds are stable fractures. This is the case with most handgun injuries. They are associated with a low infection rate and can be prophylactically treated with 48 hours of a broad-spectrum antibiotic. Transintestinal gunshot wounds require special attention. In these cases, the bullet passes through the colon, intestine, or stomach before passing through the spine. These injuries carry a significantly higher rate of infection. Broad-spectrum antibiotics should be continued for 7 to 14 days. High-energy wounds, as caused by a rifle or military assault weapon, require open debridement and stabilization.
  • Neural injury is often secondary to a blast effect in which the energy of the bullet is absorbed and transmitted to the soft tissues. Because of this unique mechanism, decompression is rarely indicated. One exception is when a bullet fragment is found in the spinal canal between the level of T12 and L5 in the presence of a neurologic deficit. Rarely, delayed bullet extraction may be indicated for lead toxicity or late neurologic deficits owing to migration of a bullet fragment. Steroids after gunshot wounds to the spine are not recommended, because they have demonstrated no neurologic benefit and appear to be associated with a higher rate of nonspinal complications.

 

PROGNOSIS AND NEUROLOGIC RECOVERY

Bradford and McBride

  • These authors modified the Frankel grading system of neurologic injury for thoracolumbar injuries, dividing Frankel D types (impaired but functional motor function) based on degree of motor function as well as bowel and bladder function:

Type A:

Complete motor and sensory loss

Type B:

Preserved sensation, no voluntary motor

Type C:

Preserved motor, nonfunctional

Type D1:

Low-functional motor (3+/5+) and/or bowel or bladder paralysis

Type D2:

Midfunctional motor (3+ to 4+/5+) and/or neurogenic bowel or bladder dysfunction

Type D3:

High-functional motor (4+/5+) and normal voluntary bowel or bladder function

Type E:

Complete motor and sensory function normal

  • In patients with thoracolumbar spine fractures and incomplete neurologic injuries, greater neurologic improvement (including return of sphincter control) was found in patients treated by anterior spinal decompression versus posterior or lateral spinal decompression.

Dall and Stauffer

  • They prospectively examined neurologic injury and recovery patterns for T12-L1 burst fractures with partial paralysis and >30% initial canal compromise.
  • Conclusions
    • Severity of neurologic injury did not correlate with fracture pattern or amount of CT measured canal compromise.
    • Neurologic recovery did not correlate with the treatment method or amount of canal decompression.
    • Neurologic recovery did correlate with the initial fracture pattern (four types):

Type I:

<15 degrees of kyphosis; maximal canal compromise at level of ligamentum flavum

Type II:

<15 degrees of kyphosis; maximal compromise at the bony posterior arch

Type III:

>15 degrees of kyphosis; maximal compromise at the bony arch

Type IV:

>15 degrees of kyphosis; maximal compromise at the level of the ligamentum flavum

  • Type I or Type II: Significant neurologic recovery occurred in >90%, regardless of the severity of the initial paralysis or treatment method.
  • Type III: Significant neurologic recovery occurred in <50%.
  • Type IV: The response was variable.

Camissa et al.

  • They associated dural tears in 37% of burst fractures with associated laminar fractures; all patients had neurologic deficits.
  • They concluded that the presence of a preoperative neurologic deficit in a patient who had a burst fracture and an associated laminar fracture was a sensitive (100%) and specific (74%) predictor of dural laceration, as well as a predictor of risk for associated entrapment of neural elements.

Keenen et al.

  • They reported an 8% incidence of dural tears in all surgically treated spine fractures, 25% in lumbar burst fractures.
  • In patients with burst fractures and a dural tear, 86% had neurologic deficits versus 42% in those with burst fractures without a dural tear.

COMPLICATIONS

Complications of spinal cord injury are covered in Chapter 8.

 

 

Pelvis

 

ANATOMY

  • The pelvic ring is composed of the sacrum and two innominate bones joined anteriorly at the symphysis and posteriorly at the paired sacroiliac joints (Figs. 29 and 30).
  • The innominate bone is formed at maturity by the fusion of three ossification centers: the ilium, the ischium, and the pubis through the triradiate cartilage at the dome of the acetabulum.
  • The pelvic brim is formed by the arcuate lines that join the sacral promontory posteriorly and the superior pubis anteriorly. Below this is the true or lesser pelvis, in which are contained the pelvic viscera. Above this is the false or greater pelvis that represents the inferior aspect of the abdominal cavity.
  • Inherent stability of the pelvis is conferred by ligamentous structures. These may be divided into two groups according to the ligamentous attachments:
    • Sacrum to ilium: The strongest and most important ligamentous structures occur in the posterior aspect of the pelvis connecting the sacrum to the innominate bones.
      • The sacroiliac ligamentous complex is divided into posterior (short and long) and anterior ligaments. Posterior ligaments provide most of the stability.
      • The sacrotuberous ligament runs from the posterolateral aspect of the sacrum and the dorsal aspect of the posterior iliac spine to the ischial tuberosity. This ligament, in association with the posterior sacroiliac ligaments, is especially important in helping maintain vertical stability of the pelvis.
      • The sacrospinous ligament is triangular, running from the lateral margins of the sacrum and coccyx and inserting on the ischial spine. It is more important in maintaining rotational control of the pelvis if the posterior sacroiliac ligaments are intact.
    • Pubis to pubis: This is the symphysis pubis.
  • Additional stability is conferred by ligamentous attachments between the lumbar spine and the pelvic ring:
    • The iliolumbar ligaments originate from the L4 and L5 transverse processes and insert on the posterior iliac crest.
    • The lumbosacral ligaments originate from the transverse process of L5 to the ala of the sacrum.
  • The transversely placed ligaments resist rotational forces and include the short posterior sacroiliac, anterior sacroiliac, iliolumbar, and sacrospinous ligaments.
  • The vertically placed ligaments resist vertical shear (VS) and include the long posterior sacroiliac, sacrotuberous, and lateral lumbosacral ligaments.

PELVIC STABILITY

Figure 29. Lateral projection of the left innominate bone. Note the muscular attachments to the ilium, ischium, and pubis.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • A stable injury is defined as one that can withstand normal physiologic forces without abnormal deformation.
  • Penetrating trauma infrequently results in pelvic ring destabilization.
  • An unstable injury may be characterized by the type of displacement as:
    • Rotationally unstable (open and externally rotated, or compressed and internally rotated).
    • Vertically unstable.

McBroom and Tile

Sectioned ligaments of the pelvis determine relative contributions to pelvic stability (these included bony equivalents to ligamentous disruptions):

  • Symphysis: pubic diastasis <2.5 cm
  • Symphysis and sacrospinous ligaments: >2.5 cm of pubic diastasis (note that these are rotational movements and not vertical or posterior displacements)
  • Symphysis, sacrospinous, sacrotuberous, and posterior sacroiliac: unstable vertically, posteriorly, and rotationally


Figure 30. Medial projection of the left innominate bone with muscle attachments and outline of the sacroiliac joint surface.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

MECHANISM OF INJURY

  • These may be divided into low-energy injuries, which typically result in fractures of individual bones, or high-energy fractures, which may result in pelvic ring disruption.
    • Low-energy injuries may result from sudden muscular contractions in young athletes that cause an avulsion injury, a low-energy fall, or a straddle-type injury.
    • High-energy injuries typically result from a motor vehicle accident, pedestrian-struck mechanism, motorcycle accident, fall from heights, or crush mechanism.
  • Impact injuries result when a moving victim strikes a stationary object or vice versa. Direction, magnitude, and nature of the force all contribute to the type of fracture.
  • Crush injuries occur when a victim is trapped between the injurious force, such as motor vehicle, and an unyielding environment, such as the ground or pavement. In addition to those factors mentioned previously, the position of the victim, the duration of the crush, and whether the force was direct or a rollover (resulting in a changing force vector) are important to understanding the fracture pattern.
  • Specific injury patterns vary by the direction of force application:
  • Anteroposterior (AP) force
    • This results in external rotation of the hemipelvis.
    • The pelvis springs open, hinging on the intact posterior ligaments.
  • Lateral compression (LC) force: This is most common and results in impaction of cancellous bone through the sacroiliac joint and sacrum. The injury pattern depends on location of force application:
    • Posterior half of the ilium: This is classic LC with minimal soft tissue disruption. This is often a stable configuration.
    • Anterior half of the iliac wing: This rotates the hemipelvis inward. It may disrupt the posterior sacroiliac ligamentous complex. If this force continues to push the hemipelvis across to the contralateral side, it will push the contralateral hemipelvis out into external rotation, producing LC on the ipsilateral side and an external rotation injury on the contralateral side.
    • Greater trochanteric region: This may be associated with a transverse acetabular fracture.
    • External rotation abduction force: This is common in motorcycle accidents.
      • Force application occurs through the femoral shafts and head when the leg is externally rotated and abducted.
      • This tends to tear the hemipelvis from the sacrum.
    • Shear force
      • This leads to a completely unstable fracture with triplanar instability secondary to disruption of the sacrospinous, sacrotuberous, and sacroiliac ligaments.
      • In the elderly individual, bone strength will be less than ligamentous strength and will fail first.
      • In a young individual, bone strength is greater, and thus ligamentous disruptions usually occur.

CLINICAL EVALUATION

  • Perform patient primary assessment (ABCDE): airway, breathing, circulation, disability, and exposure. This should include a full trauma evaluation.
  • Initiate resuscitation: Address life-threatening injuries.
  • Evaluate injuries to head, chest, abdomen, and spine.
  • Identify all injuries to extremities and pelvis, with careful assessment of distal neurovascular status.
  • Pelvic instability may result in a leg-length discrepancy involving shortening on the involved side or a markedly internally or externally rotated lower extremity.
  • The AP-LC test for pelvic instability should be performed once only and involves rotating the pelvis internally and externally.
    • first clot is the best clot Once disrupted, subsequent thrombus formation of a retroperitoneal hemorrhage is difficult because of hemodilution by administered intravenous fluid and exhaustion of the bodyís coagulation factors by the original thrombus.
  • Massive flank or buttock contusions and swelling with hemorrhage are indicative of significant bleeding.
  • Palpation of the posterior aspect of the pelvis may reveal a large hematoma, a defect representing the fracture, or a dislocation of the sacroiliac joint. Palpation of the symphysis may also reveal a defect.
  • The perineum must be carefully inspected for the presence of a lesion representing an open fracture.

HEMODYNAMIC STATUS

Retroperitoneal hemorrhage may be associated with massive intravascular volume loss. The usual cause of retroperitoneal hemorrhage secondary to pelvic fracture is a disruption of the venous plexus in the posterior pelvis. It may also be caused by a large-vessel injury, such as external or internal iliac disruption. Large-vessel injury causes rapid, massive hemorrhage with frequent loss of the distal pulse and marked hemodynamic instability. This often necessitates immediate surgical exploration to gain proximal control of the vessel before repair. The superior gluteal artery is occasionally injured and can be managed with rapid fluid resuscitation, appropriate stabilization of the pelvic ring, and embolization.

  • Options for immediate hemorrhage control include:
    • Application of military antishock trousers (MAST). This is typically performed in the field.
    • Application of an anterior external fixator.
    • Wrapping of a pelvic binder circumferentially around the pelvis (or sheet if a binder is not available).
    • Application of a pelvic C-clamp.
    • Open reduction and internal fixation (ORIF): This may be undertaken if the patient is undergoing emergency laparotomy for other indications; it is frequently contraindicated by itself because loss of the tamponade effect may encourage further hemorrhage.
    • Consider angiography or embolization if hemorrhage continues despite closing of the pelvic volume.

NEUROLOGIC INJURY

  • Lumbosacral plexus and nerve root injuries may be present, but they may not be apparent in an unconscious patient.

GENITOURINARY AND GASTROINTESTINAL INJURY

  • Bladder injury: 20% incidence occurs with pelvic trauma.
  • Urethral injury: 10% incidence occurs with pelvic fractures, in male patients much more frequently than in female patients.
    • Examine for blood at the urethral meatus or blood on catheterization.
    • Examine for a high-riding or floating prostate on rectal examination.
    • Clinical suspicion should be followed by a retrograde urethrogram.

Bowel Injury

Perforations in the rectum or anus owing to osseous fragments are technically open injuries and should be treated as such.
Infrequently, entrapment of bowel in the fracture site with gastrointestinal obstruction may occur. If either is present, the patient should undergo diverting colostomy.

 

RADIOGRAPHIC EVALUATION

Standard trauma radiographs include an AP view of the chest, a lateral view of the cervical spine, and an AP view of the pelvis.

  • AP of the pelvis (Fig. 31):
    • Anterior lesions: pubic rami fractures and symphysis displacement
    • Sacroiliac joint and sacral fractures
    • Iliac fractures
    • L5 transverse process fractures

Figure 31. Anteroposterior view of the pelvis.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

  • Special views of the pelvis include:
    • Obturator and iliac oblique views: They may be utilized in suspected acetabular fractures (see Chapter 26).
    • Inlet radiograph (Fig. 32): This is taken with the patient supine with the tube directed 60 degrees caudally, perpendicular to the pelvic brim.
      • This is useful for determining anterior or posterior displacement of the sacroiliac joint, sacrum, or iliac wing.
      • It may determine internal rotation deformities of the ilium and sacral impaction injuries.

Figure 32. Inlet view of the pelvis: technique (A) and artists sketch (B).

(Modified from Tile M. Fractures of the Pelvis and Acetabulum, 2nd ed. Baltimore: Williams & Wilkins; 1995.)

    • Outlet radiograph (Fig. 33): This is taken with the patient supine with the tube directed 45 degrees cephalad.
      • This is useful for determination of vertical displacement of the hemipelvis.
      • It may allow for visualization of subtle signs of pelvic disruption, such as a slightly widened sacroiliac joint, discontinuity of the sacral borders, nondisplaced sacral fractures, or disruption of the sacral foramina.

Figure 33. Outlet view of the pelvis: technique (A) and artists sketch (B).

(Modified from Tile M. Fractures of the Pelvis and Acetabulum, 2nd ed. Baltimore: Williams & Wilkins; 1995.)

  • Computed tomography: This is excellent for assessing the posterior pelvis, including the sacrum and sacroiliac joints.
  • Magnetic resonance imaging: It has limited clinical utility owing to restricted access to a critically injured patient, prolonged duration of imaging, and equipment constraints. However, it may provide superior imaging of genitourinary and pelvic vascular structures.
  • Stress views: Push-pull radiographs are performed while the patient is under general anesthesia to assess vertical stability.
    • Tile defined instability as ‚Č•0.5 cm of motion.
    • Bucholz, Kellam, and Browner consider ‚Č•1 cm of vertical displacement unstable.
  • Radiographic signs of instability include:
    • Sacroiliac displacement of 5 mm in any plane.
    • Posterior fracture gap (rather than impaction).
    • Avulsion of the fifth lumbar transverse process, the lateral border of the sacrum (sacrotuberous ligament), or the ischial spine (sacrospinous ligament).

CLASSIFICATION

Young and Burgess (Table 4 and Fig. 34)

This system is based on the mechanism of injury

Table 4. Injury classification keys according to the Young and Burgess system

Category

Distinguishing Characteristics

LC

Transverse fracture of pubic rami, ipsilateral or contralateral to posterior injury

I Sacral compression on side of impact

II Crescent (iliac wing) fracture on side of impact

III LC-I or LC-II injury on side of impact; contralateral open-book (APC) injury

APC

Symphyseal diastasis or longitudinal rami fractures

I Slight widening of pubic symphysis or anterior SI joint; stretched but intact anterior SI, sacrotuberous, and sacrospinous ligaments; intact posterior SI ligaments

II Widened anterior SI joint; disrupted anterior SI, sacrotuberous, and sacrospinous ligaments; intact posterior SI ligaments

III Complete SI joint disruption with lateral displacement, disrupted anterior SI, sacrotuberous, and sacrospinous ligaments; disrupted posterior SI ligaments

VS

Symphyseal diastasis or vertical displacement anteriorly and posteriorly, usually through the SI joint, occasionally through the iliac wing or sacrum

CM

Combination of other injury patterns, LC/VS being the most common

Modified from Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002:1487.

 

  • LC: This is an implosion of the pelvis secondary to laterally applied force that shortens the anterior sacroiliac, sacrospinous, and sacrotuberous ligaments. One may see oblique fractures of the pubic rami, ipsilateral or contralateral to the posterior injury.

Type I:

Sacral impaction on the side of impact. Transverse fractures of the pubic rami are stable.

Type II:

Posterior iliac wing fracture (crescent) on the side of impact with variable disruption of the posterior ligamentous structures resulting in variable mobility of the anterior fragment to internal rotation stress. It maintains vertical stability and may be associated with an anterior sacral crush injury.

Type III:

LC-I or LC-II injury on the side of impact; force continued to contralateral hemipelvis to produce an external rotation injury (‚Äúwindswept pelvis‚ÄĚ) owing to sacroiliac, sacrotuberous, and sacrospinous ligamentous disruption. Instability may result with hemorrhage and neurologic injury secondary to traction injury on the side of sacroiliac injury.

 

  • AP compression (APC): This is anteriorly applied force from direct impact or indirectly transferred via the lower extremities or ischial tuberosities resulting in external rotation injuries, symphyseal diastasis, or longitudinal rami fractures.

Figure 34. Young and Burgess classification of pelvic ring fractures.

(From Young JWR, Burgess AR. Radiologic Management of Pelvic Ring Fractures. Baltimore: Urban & Schwarzenberg, 1987, with permission.)

Type I:

Less than 2.5 cm of symphyseal diastasis. Vertical fractures of one or both pubic rami occur, with intact posterior ligaments.

Type II:

More than 2.5 cm of symphyseal diastasis; widening of sacroiliac joints; caused by anterior sacroiliac ligament disruption. Disruption of the sacrotuberous, sacrospinous, and symphyseal ligaments with intact posterior sacroiliac ligaments results in an open book injury with internal and external rotational instability; vertical stability is maintained.

Type III:

Complete disruption of the symphysis, sacrotuberous, sacrospinous, and sacroiliac ligaments resulting in extreme rotational instability and lateral displacement; no cephaloposterior displacement. It is completely unstable with the highest rate of associated vascular injuries and blood loss.

  • VS: vertically or longitudinally applied forces caused by falls onto an extended lower extremity, impacts from above, or motor vehicle accidents with an extended lower extremity against the floorboard or dashboard. These injuries are typically associated with complete disruption of the symphysis, sacrotuberous, sacrospinous, and sacroiliac ligaments and result in extreme instability, most commonly in a cephaloposterior direction because of the inclination of the pelvis. They have a highly associated incidence of neurovascular injury and hemorrhage.
  • Combined mechanical (CM): combination of injuries often resulting from crush mechanisms. The most common are VS and LC.

Tile Classification

Type A

Stable

A1:

Fractures of the pelvis not involving the ring; avulsion injuries

A2:

Stable, minimal displacement of the ring

Type B:

Rotationally unstable, vertically stable

B1:

External rotation instability; open-book injury

B2:

LC injury; internal rotation instability; ipsilateral only

B3:

LC injury; bilateral rotational instability (bucket handle)

Type C:

Rotationally, and vertically unstable

C1:

Unilateral injury

C2:

Bilateral injury, one side rotationally unstable, with the contralateral side vertically unstable

C3:

Bilateral injury, both sides rotationally and vertically unstable with an associated acetabular fracture

OTA Classification of Pelvic Fractures

See Fracture and Dislocation Compendium at http://www.ota.org/compendium/index.htm.

 

FACTORS INCREASING MORTALITY

  • Type of pelvic ring injury
    • Posterior disruption is associated with higher mortality (APC III, VS, LC III)
  • High Injury Severity Score (Tile, 1980, McMurty, 1980)
  • Associated injuries
    • Head and abdominal, 50% mortality
  • Hemorrhagic shock on admission (Gilliland, 1982)
  • Requirement for large quantities of blood
    • 24 U versus 7 U (McMurty, 1980)
  • Perineal lacerations, open fractures (Hanson, 1991)
  • Increased age (Looser, 1976)

Morel-Lavall Lesion (Skin Degloving Injury)

  • Infected in one-third of cases
  • Requires thorough debridement before definitive surgery

TREATMENT

  • The recommended management of pelvic fractures varies from institution to institution, a finding highlighting that these are difficult injuries to treat.

Nonoperative

Fractures amenable to nonoperative treatment include:

  • Lateral impaction type injuries with minimal (<1.5 cm) displacement.
  • Pubic rami fractures with no posterior displacement.
  • Gapping of pubic symphysis <2.5 cm.
  • Rehabilitation:
    • Protect weight bearing typically with a walker or crutches initially.
    • Serial radiographs are required after mobilization has begun to monitor for subsequent displacement.
    • If displacement of the posterior ring >1 cm is noted, weight bearing should be stopped. Operative treatment should be considered for gross displacement.

Tile: Stabilization Options

  • Stable (A1, A2): Stable, minimally displaced fractures with minimal disruption of the bony and ligamentous stability of the pelvic ring may successfully be treated with protected weight bearing and symptomatic treatment.
  • Open-book (B1)
    • Symphyseal diastasis <2 cm: Protected weightbearing and symptomatic treatment are indicated.
    • Symphyseal diastasis >2 cm: External fixation or symphyseal plate is performed (ORIF preferred if laparotomy for associated injuries and no open injury), with possible fixation for the posterior injury.
  • LC (B2, B3)
    • Ipsilateral only: Elastic recoil may improve pelvic anatomy. No stabilization is necessary.
    • Contralateral (bucket-handle): The posterior sacral complex is commonly compressed.
      • Leg-length discrepancy <1.5 cm: No stabilization is necessary.
      • Leg-length discrepancy >1.5 cm: The choice is external fixation versus ORIF.
  • Rotationally and vertically unstable (C1, C2, C3): External fixation with or without skeletal traction and ORIF are options.

Operative Techniques

  • External fixation: This can be applied as a construct mounted on two to three 5-mm pins spaced 1 cm apart along the anterior iliac crest, or with the use of single pins placed in the supraacetabular area in an AP direction (Hanover frame).
    • External fixation is a resuscitative fixation and can only be used for definitive fixation of anterior pelvis injuries; it cannot be used as definitive fixation of posteriorly unstable injuries.
  • Internal fixation: This significantly increases the forces resisted by the pelvic ring compared with external fixation.
    • Iliac wing fractures: Open reduction and stable internal fixation are performed using lag screws and neutralization plates.
    • Diastasis of the pubic symphysis: Plate fixation is used if no open injury or cystostomy tube is present.
    • Sacral fractures: Transiliac bar fixation may be inadequate or may cause compressive neurologic injury; in these cases, plate fixation or sacroiliac screw fixation may be indicated.
    • Unilateral sacroiliac dislocation: Direct fixation with cancellous screws or anterior sacroiliac plate fixation is used.
    • Bilateral posterior unstable disruptions: Fixation of the displaced portion of the pelvis to the sacral body may be accomplished by posterior screw fixation.

Special Considerations

  • Open fractures: In addition to fracture stabilization, hemorrhage control, and resuscitation, priority must be given to evaluation of the anus, rectum, vagina, and genitourinary system.
    • Anterior and lateral wounds generally are protected by muscle and are not contaminated by internal sources.
    • Posterior and perineal wounds may be contaminated by rectal and vaginal tears and genitourinary injuries.
    • Colostomy may be necessary for large bowel perforations or injuries to the anorectal region.
    • Colostomy is indicated for any open injury where the fecal stream will contact the open area.
  • Urologic injury
    • The incidence is 15%.
    • Blood at the meatus or a high-riding prostate may be noted.
    • Eventual swelling of the scrotum and labia (occasional bleeding artery requiring surgery) may occur.
    • Retrograde urethrogram is indicated in patients with suspicion of urologic injury, but one should ensure hemodynamic stability as embolization may be difficult because of dye extravasation.
    • Intra peritoneal bladder ruptures are repaired. Extra peritoneal ruptures may be observed.
    • Urethral injuries are repaired on a delayed basis.
  • Neurologic injury
    • L2 to S4 are possible.
    • L5 and S1 are most common.
    • Neurologic injury depends on the location of the fracture and the amount of displacement.
    • Sacral fractures: neurologic injury
      • Lateral to foramen (Denis I): 6% injury
      • Through foramen (Denis II): 28% injury
      • Medial to foramen (Denis III): 57% injury
    • Decompression of sacral foramen may be indicated if progressive loss of neural function occurs.
    • It may take up to 3 years for recovery.
  • Hypovolemic shock: origin
    • Intrathoracic bleeding
    • Intraperitoneal bleeding
      • Diagnostic tables
      • Ultrasound
      • Peritoneal tap
      • Computed tomography
    • Retroperitoneal bleeding
    • Blood loss from open wounds
    • Bleeding from multiple extremity fractures
  • Average blood replacement (Burgess, J Trauma 1990)
    • LC = 3.6 U
    • AP = 14.8 U
    • VS = 9.2 U
    • CM = 8.5 U
  • Mortality (Burgess, J Trauma 1990)
    • Hemodynamically stable patients 3%
    • Unstable patients 38%
    • LC: head injury major cause of death
    • APC: pelvic and visceral injury major cause of death
    • LC1 and LC2 ‚Üí 50% brain injury
    • LC3 (windswept pelvis: rollover/crush)
      • 60% retroperitoneal hematoma
      • 20% bowel injury
    • AP3 (comprehensive posterior instability)
      • 67% shock
      • 59% sepsis
      • 37% death
      • 18.5% adult respiratory distress syndrome (ARDS)
    • VS
      • 63% shock
      • 56% brain injury
      • 25% splenic injury
      • 25% death
      • 23% lung injury
  • Postoperative management: In general, early mobilization is desired.
    • Aggressive pulmonary toilet should be pursued with incentive spirometry, early mobilization, encouraged deep inspirations and coughing, and suctioning or chest physical therapy if necessary.
    • Prophylaxis against thromboembolic phenomena should be undertaken, with a combination of elastic stockings, sequential compression devices, and chemoprophylaxis if hemodynamic status allows. Duplex ultrasound examinations may be necessary. Thrombus formation may necessitate anticoagulation and/or vena caval filter placement.
    • Weight-bearing status may be advanced as follows:
      • Full weight bearing on the uninvolved lower extremity occurs within several days.
      • Partial weight bearing on the involved lower extremity is recommended for at least 6 weeks.
      • Full weight bearing on the affected extremity without crutches is indicated by 12 weeks.
      • Patients with bilateral unstable pelvic fractures should be mobilized from bed to chair with aggressive pulmonary toilet until radiographic evidence of fracture healing is noted. Partial weight bearing on the less injured side is generally tolerated by 12 weeks.

COMPLICATIONS

  • Infection: The incidence is variable, ranging from 0% to 25%, although the presence of wound infection does not preclude a successful result. The presence of contusion or shear injuries to soft tissues is a risk factor for infection if a posterior approach is used. This risk is minimized by a percutaneous posterior ring fixation.
  • Thromboembolism: Disruption of the pelvic venous vasculature and immobilization constitute major risk factors for the development of deep venous thromboses.
  • Malunion: Significant disability may result, with complications including chronic pain, limb length inequalities, gait disturbances, sitting difficulties, low back pain, and pelvic outlet obstruction.
  • Nonunion: This is rare, although it tends to occur more in younger patients (average age 35 years) with possible sequelae of pain, gait abnormalities, and nerve root compression or irritation. Stable fixation and bone grafting are usually necessary for union.

 

Acetabulum

 

ANATOMY

  • From the lateral aspect of the pelvis, the innominate osseous structural support of the acetabulum may be conceptualized as a two-columned construct (Judet and Letournel) forming an inverted Y (Fig. 35).
  • Anterior column (iliopubic component): This extends from the iliac crest to the symphysis pubis and includes the anterior wall of the acetabulum.
  • Posterior column (ilioischial component): This extends from the superior gluteal notch to the ischial tuberosity and includes the posterior wall of the acetabulum.
  • Acetabular dome: This is the superior weight-bearing portion of the acetabulum at the junction of the anterior and posterior columns, including contributions from each.

Figure 35. (A) A diagram of the two columns as an inverted Y supporting the acetabulum. (B) The two columns are linked to the sacral bone by the sciatic buttress. (C) Lateral aspect of the hemipelvis and acetabulum. The posterior column is characterized by the dense bone at the greater sciatic notch and follows the dotted line distally through the center of the acetabulum, the obturator foramen, and the inferior pubic ramus. The anterior column extends from the iliac crest to the symphysis pubis and includes the entire anterior wall of the acetabulum. Fractures involving the anterior column commonly exit below the anterior-inferior iliac spine as shown by the heavy dotted line. (D) The hemipelvis from its medial aspect, showing the columns from the quadrilateral plate. The area between the posterior column and the heavy dotted line, representing a fracture through the anterior column, is often considered the superior dome fragment.

(From Letournel E, Judet R. Fractures of the Acetabulum. New York: Springer-Verlag, 1964.)

  • Corona mortis
    • A vascular communication between the external iliac or deep inferior epigastric artery and the obturator artery
    • Present in up to 85% of patients
    • May extend over the superior pubic ramus; average distance from the symphysis to corona, 6 cm
  • Ascending branch of medial circumflex
    • Main blood supply to femoral head
    • Deep to quadratus femoris
  • Superior gluteal neurovascular bundle
    • Emerges from the greater sciatic notch

MECHANISM OF INJURY

  • Like pelvis fractures, these injuries are mainly caused by high-energy trauma secondary to a motor vehicle, motorcycle accident, or fall from a height.
  • The fracture pattern depends on the position of the femoral head at the time of injury, the magnitude of force, and the age of the patient.
  • Direct impact to the greater trochanter with the hip in neutral position can cause a transverse type of acetabular fracture (an abducted hip causes a low transverse fracture, whereas an adducted hip a high transverse fracture). An externally rotated and abducted hip causes anterior column injury. An internally rotated hip causes posterior column injury.
  • With indirect trauma, (e.g., a dashboard-type injury to the flexed knee), as the degree of hip flexion increases, the posterior wall is fractured in an increasingly inferior position. Similarly, as the degree of hip flexion decreases, the superior portion of the posterior wall is more likely to be involved.

CLINICAL EVALUATION

  • Trauma evaluation is usually necessary, with attention to airway, breathing, circulation, disability and exposure, depending on the mechanism of injury.
  • Patient factors, such as patient age, degree of trauma, presence of associated injuries, and general medical condition are important because they affect treatment decisions as well as prognosis.
  • Careful assessment of neurovascular status is necessary, because sciatic nerve injury may be present in up to 40% of posterior column disruptions. Femoral nerve involvement with anterior column injury is rare, although compromise of the femoral artery by a fractured anterior column has been described.
  • The presence of associated ipsilateral injuries must be ruled out, with particular attention to the ipsilateral knee in which posterior instability and patellar fractures are common.
  • Soft tissue injuries (e.g., abrasions, contusions, presence of subcutaneous hemorrhage) may provide insight into the mechanism of injury.

RADIOGRAPHIC EVALUATION

  • An anteroposterior (AP) and two Judet views (iliac and obturator oblique views) should be obtained.
  • AP view: Anatomic landmarks include the iliopectineal line (limit of anterior column), the ilioischial line (limit of posterior column), the anterior lip, the posterior lip, and the line depicting the superior weight-bearing surface of the acetabulum terminating as the medial teardrop (Fig. 36).
  • Iliac oblique radiograph (45-degree external rotation view): This best demonstrates the posterior column (ilioischial line), the iliac wing, and the anterior wall of the acetabulum (Fig. 37).

Figure 36. Diagram outlining the major landmarks: the iliopectineal line (anterior column), the ilioischial line (posterior column), the anterior lip of the acetabulum, and the posterior lip of the acetabulum.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

 

Figure 37. Iliac oblique view (A) This view is taken by rotating the patient into 45 degrees of external rotation by elevating the uninjured side on a wedge. (B) Diagram of the anatomic landmarks of the left hemipelvis on the iliac oblique view. This view best demonstrates the posterior column of the acetabulum, outlined by the ilioischial line, the iliac crest, and the anterior lip of the acetabulum.

(From Tile M. Fractures of the Pelvis and Acetabulum, 2nd ed. Baltimore: Williams & Wilkins, 1995.)

Obturator oblique view (45-degree internal rotation view): This is best for evaluating the anterior column and posterior wall of the acetabulum (Fig. 38).

Figure 38. Obterator oblique view (A) This view is taken by elevating the affected hip 45 degrees to the horizontal by means of a wedge and directing the beam through the hip joint with a 15-degree upward tilt. (B) Diagram of the anatomy of the pelvis on the obturator oblique view.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

  • Computed tomography (CT): This provides additional information regarding size and position of column fractures, impacted fractures of the acetabular wall, retained bone fragments in the joint, degree of comminution, and sacroiliac joint disruption. Three-dimensional reconstruction allows for digital subtraction of the femoral head, resulting in full delineation of the acetabular surface.

CLASSIFICATION

Judet-Letournel (Fig. 39)

Based on degree of columnar damage, there are ten fracture patterns, five elementary and five associated:

Elementary Fractures

Associated Fractures

Posterior wall

T-shaped

Posterior column

Posterior column and posterior wall

Anterior wall

Transverse and posterior wall

Anterior wall

Transverse and posterior wall

Anterior column

Anterior column/posterior hemitransverse

Transverse

Both-column


Elementary Fractures

  • Posterior wall fracture
    • This involves a separation of posterior articular surface.
    • Most of the posterior column is undisturbed.
    • It is often associated with posterior femoral head dislocation.
    • The posterior wall fragment is best visualized on the obturator oblique view.
    • Marginal impaction is often present in posterior fracture-dislocations (articular cartilage impacted into underlying cancellous bone).
      • In a series by Brumback, marginal impaction was identified in 23% of posterior fracture-dislocations requiring open reduction. This was best appreciated on CT scan.
  • Posterior column fracture
    • The ischium is disrupted.
    • The fracture line originates at the greater sciatic notch, travels across the retroacetabular surface, exits at the obturator foramen.

Figure 39. Letournel classification of acetabular fractures.

    • The ischiopubic ramus is fractured.
    • Medial displacement of the femoral head can occur.
  • Anterior wall fracture
    • Disruption of a small portion of the anterior roof and acetabulum occurs.
    • Much of anterior column is undisturbed.
    • The ischiopubic ramus is not fractured.
    • The teardrop is often displaced medially with respect to the ilioischial line.
  • Anterior column fracture
    • This is associated with disruption of the iliopectineal line.
    • It is often associated with anteromedial displacement of the femoral head.
    • It is classified according to the level at which the superior margin of the fracture line divides the innominate bone: low, intermediate, or high pattern.
    • The more superiorly the fracture line ascends, the greater the involvement of the weight-bearing aspect of the acetabulum.
    • CT may be helpful in delineating the degree of articular surface involvement.
  • Transverse fracture
    • The innominate bone is separated into two fragments, dividing the acetabular articular surface in one of three ways:
      • Transtectal: through the acetabular dome.
      • Juxtatectal: through the junction of the acetabular dome and fossa acetabuli.
      • Infratectal: through the fossa acetabuli.
    • The more superior the fracture line, the greater the displacement of the acetabular dome will be.
    • The femoral head follows the inferior ischiopubic fragment and may dislocate centrally.
    • The ilioischial line and teardrop maintain a normal relationship.
    • CT typically demonstrates an AP fracture line.

Associated Fractures

  • Associated posterior column and posterior wall fracture
    • Two elementary fracture patterns are present. The posterior wall is usually markedly displaced/rotated in relation to the posterior column. This injury represents one pattern of posterior hip dislocation that is frequently accompanied by injury to the sciatic nerve.
  • T-shaped fracture
    • This combines a transverse fracture of any type (transtectal, juxtatectal, or infratectal) with an additional vertical fracture line that divides the ischiopubic fragment into two parts. The vertical component, or stem, may exit anteriorly, inferiorly, or posteriorly depending on the vector of the injurious force. The vertical component is best seen on the obturator oblique view.
  • Associated transverse and posterior wall fracture
    • The obturator oblique view best demonstrates the position of the transverse component as well as the posterior wall element. By CT, in two-thirds of cases, the femoral head dislocates posteriorly; in one-third of cases, the head dislocates centrally.
    • Marginal impaction may exist; this is best evaluated by CT.
  • Associated anterior column and posterior hemitransverse fracture
    • This combines an anterior wall or anterior column fracture (of any type) with a fracture line that divides the posterior column exactly as it would a transverse fracture. It is termed a hemitransverse because the transverse component involves only one column.
    • Importantly, in this fracture a piece of acetabular articular surface remains nondisplaced and is the key for operative reduction of other fragments.
  • Both-column fracture
    • This is the most complex type of acetabular fracture, formerly called a central acetabular fracture.
    • Both columns are separated from each other and from the axial skeleton, resulting in a floating acetabulum.
    • The spur sign above the acetabulum on an obturator oblique radiograph is diagnostic.

OTA Classification of Acetabular Fractures

See Fracture and Dislocation Compendium at http://www.ota.org/compendium/index.htm.

 

TREATMENT

The goal of treatment is anatomic restoration of the articular surface to prevent posttraumatic arthritis (Fig. 40).

 

Figure 40. Treatment algorithm for acetabular fractures.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

 

Initial Management

The patient is usually placed in skeletal traction to allow for initial soft tissue healing, allow associated injuries to be addressed, maintain the length of the limb, and maintain femoral head reduction within the acetabulum.

Nonoperative

  • A system for roughly quantifying the acetabular dome following fracture can be employed using three measurements: the medial, anterior, and posterior roof arcs, measured on the AP, obturator oblique, and the iliac oblique views, respectively.
    • The roof arc is formed by the angle between two lines, one drawn vertically through the geometric center of the acetabulum, the other from the fracture line to the geometric center.
    • Roof arc angles are of limited utility for evaluation of both column fractures and posterior wall fractures.
  • Nonoperative treatment may be appropriate in:
    • Displacement of less than 2 to 5 mm in the dome, depending on the location of the fracture and patient factors, with maintenance of femoral head congruency out of traction, and an absence of intraarticular osseous fragments.
    • Distal anterior column or transverse (infratectal) fractures in which femoral head congruency is maintained by the remaining medial buttress.
    • Maintenance of the medial, anterior, and the posterior roof arcs greater than 45 degrees.

Operative

  • Surgical treatment is indicated for:
    • Displaced acetabular fractures (>2 to 3 mm).
    • Inability to maintain a congruent joint out of traction.
    • Large posterior wall fragment.
    • Removal of an interposed intraarticular loose fragment.
    • A fracture-dislocation that is irreducible by closed methods.
  • Surgical timing
    • Surgery should be performed within 2 weeks of injury.
    • It requires
      • A well-resuscitated patient.
      • An appropriate radiologic workup.
      • An appropriate understanding of the fracture pattern.
      • An appropriate operative team.
    • Surgical emergencies include:
      • Open acetabular fracture.
      • New-onset sciatic nerve palsy after closed reduction of hip dislocation.
      • Irreducible posterior hip dislocation.
      • Medial dislocation of femoral head against cancellous bone surface of intact ilium.
  • Morel-Lavall Lesion (Skin Degloving Injury)
    • This is infected in one-third of cases.
    • This requires thorough debridement before definitive fracture surgery.
  • Not been shown to be predictive of clinical outcome
    • Fracture pattern
    • Posterior dislocation
    • Initial displacement
    • Presence of intraarticular fragments
    • Presence of acetabular impaction
  • Has been shown to be predictive of clinical outcome
    • Injury to cartilage or bone of femoral head
      • Damage: 60% good/excellent result
      • No damage: 80% good/excellent result
    • Anatomic reduction
    • Age of patient: predictive of the ability to achieve an anatomic reduction

Stability

  • Instability is most common in posterior fracture types but may be present when large fractures of the quadrilateral plate allow central subluxation of the femoral head or anterior with major anterior wall fractures.
  • Central instability results when a quadrilateral plate fracture is of sufficient size to allow for central subluxation of the femoral head. A medial buttress with a spring plate or cerclage wire is necessary to restore stability.
  • Anterior instability results from a large anterior wall fracture or as part of an anterior type fracture with posterior hemitransverse fracture.

Congruity

  • Incongruity of the hip may result in early degenerative changes and posttraumatic osteoarthritis. Evaluation is best made by CT. Acceptance of incongruity is based on the location within the acetabulum.
  • Displaced dome fractures rarely reduce with traction; surgery is usually necessary for adequate restoration of the weight-bearing surface.
  • High transverse or T-type fractures are shearing injuries that are grossly unstable when they involve the superior, weight-bearing dome. Nonoperative reduction is virtually impossible, whereas operative reduction can be extremely difficult.
  • Displaced both-column fractures (floating acetabulum): Surgery is indicated for restoration of congruence if the roof fragment is displaced and secondary congruence cannot be obtained or if the posterior column is grossly displaced.
  • Retained osseous fragments may result in incongruity or an inability to maintain concentric reduction of the femoral head. Avulsions of the ligamentum teres need not be removed unless they are of substantial size.
  • Femoral head fractures generally require open reduction and internal fixation to maintain sphericity and congruity.
  • Soft tissue interposition may necessitate operative removal of the interposed tissues.
  • Assessment of reduction includes:
    • Restoration of pelvic lines.
    • Concentric reduction on all three views.
    • The goal of anatomic reduction.

Surgical Approaches

Approaches to the acetabulum include the Kocher-Langenbach ilioinguinal and extended iliofemoral. No single approach provides ideal exposure of all fracture types. Proper preoperative classification of the fracture configuration is essential to selecting the best surgical approach.

  • Kocher-Langenbach
    • Indications
      • Posterior wall fractures
      • Posterior column fractures
      • Posterior column/posterior wall fractures
      • Juxtatectal/infratectal transverse or transverse with posterior wall fractures
      • Some T-type fractures
    • Access
      • Entire posterior column
      • Greater and lesser sciatic notches
      • Ischial spine
      • Retroacetabular surface
      • Ischial tuberosity
      • Ischiopubic ramus
    • Limitations
      • Superior acetabular region
      • Anterior column
      • Fractures high in greater sciatic notch
    • Complications
      • Sciatic nerve palsy: 10%
      • Infection: 3%
      • Heterotopic ossification: 8% to 25%
  • Ilioinguinal
    • Indications
      • Anterior wall
      • Anterior column
      • Transverse with significant anterior displacement
      • Anterior column/posterior hemitransverse
      • Both-column
    • Access
      • Sacroiliac joint
      • Internal iliac fossa
      • Pelvic brim
      • Quadrilateral surface
      • Superior pubic ramus
      • Limited access to external iliac wing
    • Complications
      • Direct hernia: 1%
      • Significant lateral femoral circumflex artery nerve numbness: 23%
      • External iliac artery thrombosis: 1%
      • Hematoma: 5%
      • Infection: 2%
  • Extended iliofemoral
    • Indications
      • Transtectal transverse plus posterior wall or T-shaped fractures
      • Transverse fractures with extended posterior wall
      • T-shaped fractures with wide separations of the vertical stem of the those with associated pubic symphysis dislocations
      • Certain associated both column fractures
      • Associated fracture patterns or transverse fractures operated on more than 21 days following injury
    • Access
      • External aspect of the ilium
      • Anterior column as far medial as the iliopectineal eminence
      • Posterior column to the upper ischial tuberosity
    • Complications
      • Infection: 2% to 5%
      • Sciatic nerve palsy: 3% to 5%
      • Heterotopic ossification: 20% to 50% without prophylaxis

Postoperative Care

  • Indomethacin or irradiation is indicated for heterotopic ossification prophylaxis.
  • Chemical prophylaxis, sequential compression devices, and compressive stockings for thromboembolic prophylaxis are recommended.
  • Mobilization out of bed is indicated as associated injuries allow, with pulmonary toilet and incentive spirometry.
  • Full weight bearing on the affected extremity should be withheld until radiographic signs of union are present, generally by 8 to 12 weeks postoperatively.

COMPLICATIONS

  • Surgical wound infection: The risk is increased secondary to the presence of associated abdominal and pelvic visceral injuries. Local soft tissue injury from the original impact force may cause closed degloving or local abrasions. Postoperative hematoma formation occurs frequently, further contributing to potential wound infection.
  • Nerve injury
    • Sciatic nerve: The Kocher-Langenbach approach with prolonged or forceful traction can cause sciatic nerve palsy (most often the peroneal branch; incidence, 16% to 33%). The use of somatosensory-evoked potentials may decrease the risk of sciatic injury in posterior approaches.
    • Femoral nerve: The ilioinguinal approach may result in traction injury to the femoral nerve. Rarely, the femoral nerve may be lacerated by an anterior column fracture.
    • Superior gluteal nerve: This is most vulnerable in the greater sciatic notch. Injury to this nerve during trauma or surgery may result in paralysis of the hip abductors, often causing severe disability.
  • Heterotopic ossification: The incidence ranges from 3% to 69%, highest with the extended iliofemoral approach and second highest with the Kocher-Langenbach. The highest risk is a young male patient undergoing a posterolateral extensile approach in which muscle is removed. The lowest risk is with use of the ilioinguinal approach. Both indomethacin and low-dose radiation have been helpful in reducing the incidence of this complication.
  • Avascular necrosis: This devastating complication occurs in 6.6% of cases, mostly with posterior types associated with high-energy injuries.
  • Chondrolysis: This may occur with nonoperative or operative treatment, resulting in posttraumatic osteoarthritis. Concentric reduction with restoration of articular congruity may minimize this complication.

 

 

Glenohumeral Dislocation

EPIDEMIOLOGY

  • The shoulder is the most commonly dislocated major joint of the body, accounting for up to 45% of dislocations.
  • Most shoulder dislocations are anterior; this occurs between eight and nine times more frequently than posterior dislocation, the second most common direction of dislocation.
  • Inferior and superior shoulder dislocations are rare.

ANATOMY (FIG. 41)

 

Figure 41. Views of the shoulder bony anatomy.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

  • Glenohumeral stability depends on various passive and active mechanisms, including:
    • Passive:
      • Joint conformity.
      • Vacuum effect of limited joint volume.
      • Adhesion and cohesion owing to the presence of synovial fluid
      • Scapular inclination: for >90% of shoulders, the critical angle of scapular inclination is between 0 and 30 degrees, below which the glenohumeral joint is considered unstable and prone to inferior dislocation.
      • Ligamentous and capsular restraints (Fig. 42).
        • Joint capsule: Redundancy prevents significant restraint, except at terminal ranges of motion. The anteroinferior capsule limits anterior subluxation of the abducted shoulder. The posterior capsule and teres minor limit internal rotation. The anterior capsule and lower subscapularis restrain abduction and external rotation.
        • Superior glenohumeral ligament: This is the primary restraint to inferior translation of the adducted shoulder.
        • Middle glenohumeral ligament: This is variable, poorly defined, or absent in 30%. It limits external rotation at 45 degrees of abduction.
        • Inferior glenohumeral ligament: This consists of three bands, the superior of which is of primary importance to prevent anterior dislocation of the shoulder. It limits external rotation at 45 to -90 degrees of abduction.
      • Glenoid labrum.
      • Bony restraints: acromion, coracoid, glenoid fossa.
    • Active:
      • Biceps, long-head.
      • Rotator cuff.
  • Coordinated shoulder motion involves:
    • Glenohumeral motion.
    • Scapulothoracic motion.
    • Clavicular and sternoclavicular motion.
    • Acromioclavicular motion.
  • Pathoanatomy of shoulder dislocations:
    • Stretching or tearing of the capsule.
    • Usually off the glenoid, but occasionally off the humeral avulsion of the glenohumeral ligaments (HAGL lesion).
  • Labral damage.

Figure 42. Anterior glenohumeral ligaments. This drawing shows the anterosuperior, anteromedial, and anteroinferior glenohumeral ligaments. The anteromedial and anteroinferior glenohumeral ligaments are often avulsed from the glenoid or glenoid labrum in traumatic anterior instability.

(From Grantís Atlas of Anatomy, 4th ed. Baltimore: Williams & Wilkins, 1956.)

    • A Bankart lesion refers to avulsion of anteroinferior labrum off the glenoid rim. It may be associated with a glenoid rim fracture (bony Bankart).
  • Hill-Sachs lesion: A posterolateral head defect is caused by an impression fracture on the glenoid rim; this is seen in 27% of acute anterior dislocations and 74% of recurrent anterior dislocations (Fig. 43).

Figure 43. Hill-Sachs lesion associated with anterior shoulder dislocation. On dislocation, the posterior aspect of the humeral head engages the anterior glenoid rim. The glenoid rim then initiates an impression fracture that can enlarge.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • Shoulder dislocation with associated rotator cuff tear.
    • This is common in older patients.
      • >40 years of age: 35% to 40%
      • >60 years of age: may be as high as 80%
    • Beware of inability to lift the arm in an older patient following a dislocation.

ANTERIOR GLENOHUMERAL DISLOCATION

Incidence

  • Anterior dislocations represent 90% of shoulder dislocations.

Mechanism of Injury

Anterior glenohumeral dislocation may occur as a result of trauma, secondary to either direct or indirect forces.

  • Indirect trauma to the upper extremity with the shoulder in abduction, extension, and external rotation is the most common mechanism.
  • Direct, anteriorly directed impact to the posterior shoulder may produce an anterior dislocation.
  • Convulsive mechanisms and electrical shock typically produce posterior shoulder dislocations, but they may also result in an anterior dislocation.
  • Recurrent instability related to congenital or acquired laxity or volitional mechanisms may result in anterior dislocation with minimal trauma.

Clinical Evaluation

  • It is helpful to determine the nature of the trauma, the chronicity of the dislocation, pattern of recurrence with inciting events, and the presence of laxity or a history of instability in the contralateral shoulder.
  • The patient typically presents with the injured shoulder held in slight abduction and external rotation. The acutely dislocated shoulder is painful, with muscular spasm.
  • Examination typically reveals squaring of the shoulder owing to a relative prominence of the acromion, a relative hollow beneath the acromion posteriorly, and a palpable mass anteriorly.
  • A careful neurovascular examination is important, with attention to axillary nerve integrity. Deltoid muscle testing is usually not possible, but sensation over the deltoid may be assessed. Deltoid atony may be present and should not be confused with axillary nerve injury. Musculocutaneous nerve integrity can be assessed by the presence of sensation on the anterolateral forearm (Fig. 44).

Figure 44. Technique for testing axillary nerve function. With the arm adducted and stabilized by the examiner, the patient is asked to abduct the arm. The motor component (A) of the axillary nerve is documented by observing or palpating deltoid muscle contraction. The sensory component (B) of the axillary nerve is documented by testing the sensation to the lateral aspect of the upper arm.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • Patients may present after spontaneous reduction or reduction in the field. If the patient is not in acute pain, examination may reveal a positive apprehension test, in which passive placement of the shoulder in the provocative position (abduction, extension, and external rotation) reproduces the patientís sense of instability and pain (Fig. 45).

Figure 45. Evaluation of the injured shoulder in varying degrees of abduction. Top left: External rotation force is applied to the arm in 45 degrees of abduction. Top right: The shoulder is abducted 90 degrees. Next, the external rotation force with some extension is applied, which produces pain, usually posteriorly, and marked apprehension in the patient. This position most commonly produces pain and severe apprehension. Bottom left: The external rotation and extension force is applied to the arm in 120 degrees of abduction. This causes apprehension in some patients but not as marked with the arm in 90 degrees of abduction. Bottom right: The Feagin test. With the patients elbow resting on the top of the physicians shoulder, a downward force on the proximal humerus in some instances produces apprehension.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2001.)

 

Radiographic Evaluation

  • Trauma series of the affected shoulder: Anteroposterior (AP), scapular-Y, and axillary views taken in the plane of the scapula (Figs. 46 and 47).
  • Velpeau axillary: If a standard axillary cannot be obtained because of pain, the patient may be left in a sling and leaned obliquely backward 45 degrees over the cassette. The beam is directed caudally, orthogonal to the cassette, resulting in an axillary view with magnification (Fig. 48).

 

Figure 46. Technique for obtaining anteroposterior (AP) (upper panel) and true AP (lower panel) x-rays of the shoulder. In an AP view, the x-ray actually represents an oblique view of the shoulder joint. In a true AP view, the x-ray beam is parallel to the joint so overlap between the humeral head and the glenoid surface is minimal.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Figure 47. (A) The axillary lateral x-ray view. Ideally, the arm is abducted 70 to 90 degrees and the beam is directed superiorly up to the x-ray cassette. (B) When the patient cannot fully abduct the arm, a curved cassette can be placed in the axilla and the beam can be directed inferiorly through the glenohumeral joint onto the cassette.

(From Rockwood CA, Szalay EA, Curtis RJ, et al. X-ray evaluation of shoulder problems. In: Rockwood CA, Matsen FA III, eds. The Shoulder. Philadelphia: WB Saunders, 1990:119225.)

Figure 48. Positioning of the patient for the Velpeau axillary lateral view x-ray.

(Modified from Bloom MH, Obata WG. Diagnosis of posterior dislocation of the shoulder with use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am 1967;49: 943949.)

  • Special views:
    • West Point axillary: This is taken with patient prone with the beam directed cephalad to the axilla 25 degrees from the horizontal and 25 degrees medial. It provides a tangential view of the anteroinferior glenoid rim (Fig. 49).

Figure 49. West Point view for the identification of a glenoid rim lesion. This x-ray is taken with the patient in the prone position. The beam is angled approximately 25 degrees (A) to provide a tangential view of the glenoid. In addition, the beam is angled 25 degrees downward (B) to highlight the anterior and posterior aspects of the glenoid. In this fashion, the entire glenoid rim can be clearly visualized.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

    • Hill-Sachs view: This AP radiograph is taken with the shoulder in maximal internal rotation to visualize a posterolateral defect.
    • Stryker notch view: The patient is supine with the ipsilateral palm on the crown of the head and the elbow pointing straight upward. The x-ray beam is directed 10 degrees cephalad, aimed at the coracoid. This view can visualize 90% of posterolateral humeral head defects (Fig. 50).

Figure 50. (A) The position of the patient for the Stryker notch view. The patient is supine with the cassette posterior to the shoulder. The humerus is flexed approximately 120 degrees so the hand can be placed on top of the patientís head. Note that the angle of the x-ray tube is 10 degrees superior. (B) Defects in the posterolateral aspect of the humeral head are seen in three different patients with recurring anterior dislocations of the shoulder.

(Modified from Hall RH, Isaac F, Booth CR. Dislocation of the shoulder with special reference to accompanying small fractures. J Bone Joint Surg 1959;41:489494.)

    • Computed tomography may be useful in defining humeral head or glenoid impression fractures, loose bodies, and anterior labral bony injuries (bony Bankart lesion).
  • Single- or double-contrast arthrography may be utilized to evaluate rotator cuff pathologic processes.
  • Magnetic resonance imaging may be used to identify rotator cuff, capsular, and glenoid labral (Bankart lesion) pathologic processes.

Classification

 

Degree of Stability:

Dislocation versus Subluxation

Chronology:

Congenital
Acute versus chronic
Locked (fixed)
Recurrent
Acquired: generally from repeated minor injuries (swimming, gymnastics, weights); labrum often intact but with capsular laxity; increased glenohumeral joint volume; subluxation common

Force:

Atraumatic: usually owing to congenital laxity; noinjury; often asymptomatic; self-reducing
Traumatic: usually caused by one major injury; anterior or inferior labrum may be detached (Bankart lesion); unidirectional; generally requires assistance for reduction

Patient contribution:

Voluntary versus involuntary

Direction:

Subcoracoid
Subglenoid
Intrathoracic

 

Treatment

Nonoperative

  • Closed reduction should be performed after adequate clinical evaluation and administration of analgesics and/or sedation. Described techniques include:
    • Traction-countertraction (Fig. 51)

Figure 51. Closed reduction of the left shoulder with traction against countertraction.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

    • Hippocratic technique: This is effective with only one person performing reduction, with one foot placed across the axillary folds and onto the chest wall, with gentle internal and external rotation with axial traction on the affected upper extremity.
    • Stimson technique: After administration of analgesics and/or sedatives, the patient is placed prone on the stretcher with the affected upper extremity hanging free. Gentle, manual traction or 5 lb of weight is applied to the wrist, with reduction effected over 15 to 20 minutes (Fig. 52).

Figure 52. The Stimson technique for closed shoulder reduction. With the patient in prone position, a weight is hung from the wrist to distract the shoulder joint. Eventually, with sufficient fatigue in the shoulder musculature, the joint can be easily reduced.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

    • Milch technique: With the patient supine and the upper extremity abducted and externally rotated, thumb pressure is applied by the physician to push the humeral head into place.
    • Kocher maneuver: The humeral head levered on the anterior glenoid to effect reduction; this is not recommended because of increased risk of fracture.
  • Postreduction care includes immobilization for 2 to 5 weeks. A shorter period of immobilization may be used for patients older than 40 years of age because stiffness of the ipsilateral hand, wrist, elbow, and shoulder tends to complicate treatment. Younger patients with a history of recurrent dislocation may require longer periods of immobilization.
  • In comparison to a simple sling, immobilization in a Velpeau dressing does not appear to alter the subsequent development of recurrent instability.
  • Aggressive occupational therapy should be instituted following immobilization, including increasing degrees of shoulder external rotation, flexion, and abduction as time progresses, accompanied by full, active range of motion to the hand, wrist, and elbow.
  • Irreducible acute anterior dislocation (rare) is usually the result of interposed soft tissue and requires open reduction.

Operative

  • Indications for surgery include:
    • Soft tissue interposition.
    • Displaced greater tuberosity fracture.
    • Glenoid rim fracture >5 mm in size.
    • Selective repair in the acute period (e.g., in young athletes).
  • Surgical options for stabilization include repair of the anterior labrum, capsular shift, capsulorrhaphy, muscle or tendon transfers, and bony transfers. Recent developments include the use of arthroscopy for diagnostic and therapeutic purposes (e.g., arthroscopic anterior labral repair), as well as thermal capsulorrhaphy.
  • Postoperative management typically includes the use of a shoulder immobilizer for 3 weeks in patients <30 years, 2 weeks for patients 30 to 40 years, and 1 to 2 weeks for patients >50 years of age, depending on the type of surgical stabilization. Patients are allowed to remove the immobilizer two to four times per day for shoulder, wrist, and hand range-of-motion exercises. Occupational therapy is aimed at active and passive range of motion and regaining upper extremity strength.

Complications

  • Recurrent anterior dislocation: related to ligament and capsular changes.
    • The most common complication after dislocation is recurrent dislocation
    • Incidence:
      • Age 20 years: 80% to 92% (lower in non-athletes)
      • Age 30 years: 60%
      • Age 40 years: 10% to 15%
    • Most recurrences occur within the first 2 years and tend to occur in men.
    • Prognosis is most affected by age at the time of initial dislocation.
    • Incidence is unrelated to the type or length of immobilization.
    • Patient activity has been identified as an independent factor for developing recurrent instability.
  • Osseous lesions:
    • Hill-Sachs lesion
    • Glenoid lip fracture (bony Bankart lesion)
    • Greater tuberosity fracture
    • Fracture of acromion or coracoid
    • Posttraumatic degenerative changes
  • Soft tissue injuries:
    • Rotator cuff tear (older patients)
    • Capsular or subscapularis tendon tears
  • Vascular injuries: These typically occur in elderly patients with atherosclerosis and usually involve the axillary artery. They may occur at the time of open or closed reduction.
  • Nerve injuries: These involve particularly the musculocutaneous and axillary nerves, usually in elderly individuals; neurapraxia almost always recovers, but if it persists beyond 3 months it requires further evaluation with possible exploration.

POSTERIOR GLENOHUMERAL DISLOCATION

Incidence

  • These injuries represent 10% of shoulder dislocations and 2% of shoulder injuries.
  • They are often unrecognized by primary care and emergency physicians, with 60% to 80% missed on initial examination.

Mechanism of Injury

  • Indirect trauma: This is the most common mechanism.
    • The shoulder typically is in the position of adduction, flexion, and internal rotation.
    • Electric shock or convulsive mechanisms may produce posterior dislocations owing to the greater muscular force of the internal rotators (latissimus dorsi, pectoralis major, and subscapularis muscles) compared with the external rotators of the shoulder (infraspinatus and teres minor muscles).
  • Direct trauma: This results from force application to the anterior shoulder, resulting in posterior translation of the humeral head.

Clinical Evaluation

  • Clinically, a posterior glenohumeral dislocation does not present with striking deformity; the injured upper extremity is typically held in the traditional sling position of shoulder internal rotation and adduction.
  • A careful neurovascular examination is important to rule out axillary nerve injury, although it is much less common than with anterior glenohumeral dislocation.
  • On examination, limited external rotation (often <0 degrees) and limited anterior forward elevation (often <90 degrees) may be appreciated.
  • A palpable mass posterior to the shoulder, flattening of the anterior shoulder, and coracoid prominence may be observed.

Radiographic Evaluation

  • Trauma series of the affected shoulder: AP, scapular-Y, and axillary views. A Velpeau axillary view (see earlier) may be obtained if the patient is unable to position the shoulder for a standard axillary view.
  • On a standard AP view of the shoulder, signs suggestive of a posterior glenohumeral dislocation include:
    • Absence of the normal elliptic overlap of the humeral head on the glenoid.
    • Vacant glenoid sign: The glenoid appears partially vacant (space between anterior rim and humeral head >6 mm).
    • Trough sign: impaction fracture of the anterior humeral head caused by the posterior rim of glenoid (reverse Hill-Sachs lesion). This is reported to be present in 75% of cases.
    • Loss of profile of neck of humerus: The humerus is in full internal rotation.
    • Void in the superior/inferior glenoid fossa, owing to inferosuperior displacement of the dislocated humeral head.
  • Glenohumeral dislocations are most readily recognized on the axillary view; this view may also demonstrate the reverse Hill-Sachs defect.
  • Computed tomography scans are valuable in assessing the percentage of the humeral head involved with an impaction fracture.

Classification

Etiologic Classification

Traumatic:

Sprain, subluxation, dislocation, recurrent, fixed (unreduced)

Atraumatic:

Voluntary, congenital, acquired (due to repeated microtrauma)

Anatomic Classification

Subacromial (98%):

Articular surface directed posteriorly with no gross displacement of the humeral head as in anterior dislocation; lesser tuberosity typically occupies glenoid fossa; often associated with an impaction fracture on the anterior humeral head

Subglenoid (very rare):

Humeral head posterior and inferior to the glenoid

Subspinous (very rare):

Humeral head medial to the acromion and inferior to the spine of the scapula

 

Treatment

Nonoperative

  • Closed reduction requires full muscle relaxation, sedation, and analgesia.
    • The pain from an acute, traumatic posterior glenohumeral dislocation is usually greater than with an anterior dislocation and may require general anesthesia for reduction.
    • With the patient supine, traction should be applied to the adducted arm in the line of deformity with gentle lifting of the humeral head into the glenoid fossa.
    • The shoulder should not be forced into external rotation, because this may result in a humeral head fracture if an impaction fracture is locked on the posterior glenoid rim.
    • If prereduction radiographs demonstrate an impaction fracture locked on the glenoid rim, axial traction should be accompanied by lateral traction on the upper arm to unlock the humeral head.
  • Postreduction care should consist of a sling and swathe if the shoulder is stable. If the shoulder subluxes or redislocates in the sling and swathe, a shoulder spica should be placed with amount of external rotation determined by the position of stability. Immobilization is continued for 3 to 6 weeks, depending on the age of the patient and stability of the shoulder.
    • With a large anteromedial head defect, better stability may be achieved with immobilization in external rotation.
    • External rotation and deltoid isometric exercises may be performed during the period of immobilization.
    • After discontinuation of immobilization, an aggressive internal and external rotator strengthening program is instituted.

Operative

  • Indications for surgery include:
    • Major displacement of an associated lesser tuberosity fracture.
    • A large posterior glenoid fragment.
    • Irreducible dislocation or an impaction fracture on the posterior glenoid preventing reduction.
    • Open dislocation.
    • An anteromedial humeral impaction fracture (reverse Hill-Sachs lesion):
    • Twenty to 40% humeral head involvement: transfer the lesser tuberosity with attached subscapularis into the defect (modified McLaughlin procedure).
    • Greater than 40% humeral head involvement: hemiarthroplasty with neutral version of the prosthesis.
  • Surgical options include open reduction, infraspinatus muscle/tendon plication (reverse Putti-Platt procedure), long head of the biceps tendon transfer to the posterior glenoid margin (Boyd-Sisk procedure), humeral and glenoid osteotomies, and capsulorraphy.
  • Voluntary dislocators should be treated nonoperatively, with counseling and strengthening exercises.

Complications

  •  
  • Fractures: These include fractures of the posterior glenoid rim, humeral shaft, lesser and greater tuberosities, and humeral head.
  • Recurrent dislocation: The incidence is increased with atraumatic posterior glenohumeral dislocations, large anteromedial humeral head defects resulting from impaction fractures on the glenoid rim, and large posterior glenoid rim fractures. They may require surgical stabilization to prevent recurrence.
  • Neurovascular injury: This is much less common in posterior versus anterior dislocation, but it may include injury to the axillary nerve as it exits the quadrangular space or to the nerve to the infraspinatus (branch of the suprascapular nerve) as it traverses the spinoglenoid notch.
  • Anterior subluxation: This may result from overtightening posterior structures, forcing the humeral head anteriorly. It may cause limited flexion, adduction, and internal rotation.

INFERIOR GLENOHUMERAL DISLOCATION (LUXATIO ERECTA)

  • This very rare injury is more common in elderly individuals.

Mechanism of Injury (Fig. 53)

  • It results from a hyperabduction force causing impingement of the neck of the humerus on the acromion, which levers the humeral head out inferiorly.

Figure 53. Locked inferior dislocation of the glenohumeral joint, also known as luxatio erectae. With hyperabduction of the arm, the lateral acromion acts as a lever against the proximal humerus to dislocate the shoulder inferiorly. After dislocation, the humeral head is locked inferior to the glenoid rim. In these patients, the rotator cuff tendons are typically detached from the humeral head, and there may also be an associated fracture of the greater tuberosity.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • The superior aspect of articular surface is directed inferiorly and is not in contact with the inferior glenoid rim. The humeral shaft is directed superiorly.
  • Rotator cuff avulsion and tear, pectoralis injury, proximal humeral fracture, and injury to the axillary artery or brachial plexus are common.

Clinical Evaluation

  • Patients typically present in a characteristic salute fashion, with the humerus locked in 110 to 160 degrees of abduction and forward elevation. Pain is usually severe.
  • The humeral head is typically palpable on the lateral chest wall and axilla.
  • A careful neurovascular examination is essential, because neurovascular compromise almost always complicates these dislocations.

Radiographic Evaluation

  • Trauma series of the affected shoulder: AP, scapular-Y, and axillary views are taken.
  • The AP radiograph is typically diagnostic, with inferior dislocation of the humeral head and superior direction of the humeral shaft along the glenoid margin.
  • The radiograph must be carefully scrutinized for associated fractures, which are common and may be clinically not detected because of a diffusely painful shoulder.

Treatment

Nonoperative

  • Reduction may be accomplished by the use of traction-countertraction maneuvers.
  • Axial traction should be performed in line with the humeral position (superolaterally), with a gradual decrease in shoulder abduction. Countertraction should be applied with a sheet around the patient, in line with, but opposite to the traction vector.
  • The arm should be immobilized in a sling for 3 to 6 weeks, depending on the age of the patient. Older individuals may be immobilized for shorter periods to minimize shoulder stiffness.

Operative

  • Occasionally, the dislocated humeral head buttonholes through the inferior capsule and soft tissue envelope, preventing closed reduction. Open reduction is then indicated with enlarging of the capsular defect and repair of the damaged structures.

Complications

  • Neurovascular compromise: This complicates nearly all cases of inferior glenohumeral dislocation, but it usually recovers following reduction.

SUPERIOR GLENOHUMERAL DISLOCATION

  • This very rare injury is less common than inferior glenohumeral dislocation.

Mechanism of Injury

  • Extreme anterior and superior directed force applied to the adducted upper extremity, such as a fall from a height onto the upper extremity, forces the humeral head superiorly from the glenoid fossa.
  • It is associated with fractures of the acromion, clavicle, coracoid, and humeral tuberosities, as well as injury to the acromioclavicular joint.
  • Typically it is accompanied by soft tissue injury to the rotator cuff, glenohumeral capsule, biceps tendon, and surrounding musculature.

Clinical Evaluation

  • The patient typically presents with a foreshortened upper extremity held in adduction.
  • Clinical examination typically reveals a palpable humeral head above the level of the acromion.
  • Neurovascular injuries are common and must be ruled out.

Radiographic Evaluation

  • Trauma series of the affected shoulder: AP, scapular-Y, and axillary views are obtained.
  • The AP radiograph is typically diagnostic, with dislocation of the humeral head superior to the acromion process.
  • The radiograph must be carefully scrutinized for associated fractures, which are common and may be clinically not detected because of a diffusely painful shoulder.

Treatment

  • Closed reduction should be attempted with the use of analgesics and sedatives.
  • Axial traction with countertraction may be applied in an inferior direction, with lateral traction applied to the upper arm to facilitate reduction.
  • As with inferior dislocations, soft tissue injury and associated fractures are common; irreducible dislocations may require open reduction.

Complications

  • Neurovascular complications are usually present and typically represent traction injuries that resolve with reduction.

 

Elbow Dislocation

EPIDEMIOLOGY

  • Accounts for 11% to 28% of injuries to the elbow.
  • Posterior dislocation is most common.
  • Simple dislocations are those without fracture.
  • Complex dislocations are those that occur with an associated fracture and represent just under 50% of elbow dislocations.
  • Highest incidence in the 10- to 20-year old age group associated with sports injuries, although recurrent dislocation is uncommon.

ANATOMY

  • The elbow is a ‚Äúmodified hinge‚ÄĚ joint with a high degree of intrinsic stability owing to joint congruity, opposing tension of triceps and flexors, and ligamentous constraints.
  • The three separate articulations are:
    • Ulnohumeral (hinge).
    • Radiohumeral (rotation).
    • Proximal radioulnar (rotation).
  • Stability (Fig. 54)
    • Anterior-posterior: trochlea-olecranon fossa (extension); coronoid fossa, radiocapitellar joint, biceps-triceps-brachialis (flexion).
    • Valgus: The medial collateral ligament (MCL) complex: the anterior bundle is the primary stabilizer in flexion and extension, and the anterior capsule and radiocapitellar joint function in extension.
    • Varus: The lateral ulnar collateral ligament is static, and the anconeus muscle is dynamic.
    • Function of the MCL
      • It is the primary medial stabilizer, especially the anterior band.
      • Full extension provides 30% of valgus stability.
      • Ninety degrees of flexion provides >50% of valgus stability.
      • Resection of anterior band will cause gross instability except in extension.
    • Lateral ligaments
      • These prevent posterior subluxation and rotation of the ulna away from the humerus with the forearm supination (posterolateral rotatory instability).
  • Normal range of motion: 0 to 150 degrees flexion, 85 degrees supination, and 80 degrees pronation.
  • Functional range of motion requires: 30 to 130 degrees flexion, 50 degrees supination, and 50 degrees pronation.

MECHANISM OF INJURY

  • Most commonly, injury is caused by a fall onto an outstretched hand or elbow, resulting in a levering force to unlock the olecranon from the trochlea combined with translation of the articular surfaces to produce the dislocation.
  • Posterior dislocation: This is a combination of elbow hyperextension, valgus stress, arm abduction, and forearm supination.

Figure 54. The elbow is an inherently stable joint. (A) The trochlear notch of the ulna provides a nearly 180-degree capture of the trochlea, which tilts posteriorly approximately 30 degrees. (B) The ridge in the center of the trochlear notch interdigitates with a groove on the trochlea, further enhancing stability. (C) Flexion of the elbow is enhanced by the anterior translation of the trochlea with respect to the humeral shaft as well as the coronoid and radial fossae on the anterior surface of the humerus that accept the coronoid process and radial head respectively. (D) Posteriorly, the olecranon fossa enhances extension by accommodating the olecranon process.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • Anterior dislocation: A direct force strikes the posterior forearm with the elbow in a flexed position.
  • Most elbow dislocations and fracture-dislocations result in injury to all the capsuloligamentous stabilizers of the elbow joint. The exceptions include fracture-dislocations of the olecranon and injuries with fractures of the coronoid involving nearly the entire coronoid process.
  • The capsuloligamentous injury progresses from lateral to medial; the elbow can completely dislocate with the anterior band of the MCL remaining intact. There is a variable degree of injury to the common flexor and extensor musculature (Fig. 55).

Figure 55. The capsuloligamentous structures of the elbow are injured in a lateral to medial progression during dislocation of the elbow. The elbow can dislocate with the anterior band of the medial collateral ligament (MCL) remaining intact.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

CLINICAL EVALUATION

  • Patients typically guard the injured upper extremity, which shows variable gross instability and swelling.
  • A careful neurovascular examination is essential and should be performed before radiography or manipulation.
  • Following manipulation or reduction, repeat neurovascular examination should be performed to assess neurovascular status.
  • Serial neurovascular examinations should be performed when massive antecubital swelling exists or when the patient is felt to be at risk for compartment syndrome.
  • Angiography may be necessary to evaluate vascular compromise.
    • Following reduction, if arterial flow is not reestablished and the hand remains poorly perfused, the patient should be prepared for arterial reconstruction with saphenous vein grafting.
    • Angiography should be performed in the operating room and should never delay operative intervention when vascular compromise is present.
    • The radial pulse may be present with brachial artery compromise as a result of collateral circulation.

ASSOCIATED INJURIES

  • Associated fractures most often involve the radial head and/or coronoid process of the ulna.
  • Acute neurovascular injuries are uncommon; the ulnar nerve and anterior interosseous branches of the median nerve are most commonly involved.
  • The brachial artery may be injured, particularly with an open dislocation.

RADIOGRAPHIC EVALUATION

  • Standard anteroposterior and lateral radiographs of the elbow should be obtained.
  • Radiographs should be scrutinized for associated fractures about the elbow.

CLASSIFICATION

  • Simple versus complex (associated with fracture)
  • According to the direction of displacement of the ulna relative to the humerus (Fig. 56):
    • Posterior
    • Posterolateral
    • Posteromedial
    • Lateral
    • Medial
    • Anterior

Figure 56. Elbow dislocations.

(From Browner BD, Jupiter JB, Levine AM, eds. Skeletal Trauma. Philadelphia: WB Saunders, 1992:1142, with permission.)

 

TREATMENT PRINCIPLES

  • Restoration of the inherent bony stability of the elbow is the goal.
  • Restoration of the trochlear notch of the ulna, particularly the coronoid process, is also the goal.
  • Radiocapitellar contact is very important to the stability of the injured elbow.
  • The lateral collateral ligament is more important than the MCL in the setting of most cases of traumatic elbow instability.
  • The trochlear notch (coronoid and olecranon), radial head, and lateral collateral ligament should be repaired or reconstructed, but the MCL rarely needs to be repaired.
  • If the elbow is stable, or can be made stable with surgery on the lateral side, the MCL will heal properly with active motion, and its repair will not be necessary for stability.
  • Morrey recommended that the elbow should not redislocate before reaching 45 degrees of flexion from a fully flexed position; Jupiter and Ring recommended that the elbow should be able to go to 30 degrees before substantial subluxation or dislocation.

 

Fracture-Dislocations

 

 

This is an elbow dislocation with an associated fracture about the elbow.

  • Radial head: These make up 5% to 11% of cases.
  • Medial or lateral epicondyle (12% to 34%): They may result in mechanical block following closed reduction owing to entrapment of fragment.
  • Coronoid process (5% to 10%): These are secondary to avulsion by brachialis muscle and are most common with posterior dislocation.
    • Types I, II, and III, based on size of fragment (Fig. 57):
      • Type I, avulsion of the tip of the coronoid process.
      • Type II, a single or comminuted fragment involving 50% of the coronoid process or less.
      • Type III, a single or comminuted fragment involving >50% of the process.
  • Elbow dislocations that are associated with one or more intraarticular fractures are at greater risk for recurrent or chronic instability.
  • Fracture-dislocations of the elbow usually occur in one of several distinct, recognizable injury patterns, including:
    • Posterior dislocation with fracture of the radial head.
    • Posterior dislocation with fractures of the radial head and coronoid process the so-called terrible triad injury.
    • Varus posteromedial rotational instability pattern injuries.
    • Anterior olecranon fracture-dislocations.
    • Posterior olecranon fracture-dislocations.
  • The following observations may be useful in guiding treatment:
    • Terrible triad injuries nearly always have a small transverse fracture of the tip of the coronoid including the anterior capsular attachment. Much less commonly, the coronoid fracture is either very large or involves the anteromedial facet of the coronoid preferentially.

Figure 57. Regan and Morrey classification of coronoid fractures.

(From Regan W, Morrey BF. Fractures of coronoid process of the ulna. J Bone Joint Surg 1989;71:13481354, with permission.)

    • Varus posteromedial rotational instability pattern injuries are defined by a fracture of the anteromedial facet of the coronoid process.
    • In the setting of an olecranon fracture-dislocation, the coronoid fracture can be one simple large fragment, it can be fragmented in to two or three large pieces (anteromedial facet, central, and lesser sigmoid notch) with or without a tip fragment, or it can be more comminuted.

Types of Elbow Instability

  • Posterolateral rotatory instability (elbow dislocations with or without associated fractures)
  • Varus posteromedial rotational instability (anteromedial coronoid facet fractures)
  • Olecranon fracture-dislocations

Posterolateral Rotatory Instability (Fig. 58)

  • This results in dislocation of the elbow with or without fractures of the radial head and coronoid.
  • This occurs during a fall on to the outstretched arm that create a valgus, axial, and posterolateral rotatory force. The ulna and the forearm supinate away from the humerus and dislocate posteriorly.
  • This may result in injury to the radial head or coronoid.
  • The soft tissue injury proceeds from lateral to medial, with the anterior band of the MCL being the last structure injured.
  • It is possible to dislocate the elbow with the anterior band of the MCL remaining intact.

Varus, Posteromedial Rotational Instability

  • This occurs with a fall onto the outstretched arm that creates a varus stress, axial load, and posteromedial rotational force to the elbow.

Figure 58. Posterolateral rotatory instability (PLRI) occurs in several stages. Elbow dislocation is the final stage.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • This results in fracture of the anteromedial facet of the coronoid process and (1) injury to the lateral collateral ligament, (2) fracture of the olecranon, or (3) an additional fracture of the coronoid at its base.

Anterior Olecranon Fracture-Dislocations

  • These result from a direct blow to the flexed elbow.
  • Some authors suggest that these injuries may result from the same mechanism that usually creates elbow dislocations, particularly in older osteopenic individuals.

Instability Scale (Morrey)

Type I:

Posterolateral rotatory instability; positive pivot shift test; lateral ulnar collateral ligament disrupted

Type II:

Perched condyles; varus instability; lateral ulnar collateral ligament, anterior and posterior capsule disrupted

Type IIIa:

Posterior dislocation; valgus instability; lateral ulnar collateral ligament, anterior and posterior capsule, and posterior MCL disrupted

Type IIIb:

Posterior dislocation; grossly unstable; lateral ulnar collateral ligament, anterior and posterior capsule, anterior and posterior MCL disrupted

TREATMENT

Simple Elbow Dislocation

Nonoperative

  • Acute simple elbow dislocations should undergo closed reduction with the patient under sedation and adequate analgesia. Alternatively, general or regional anesthesia may be used.
  • Correction of medial or lateral displacement followed by longitudinal traction and flexion is usually successful for posterior dislocations (Fig. 59).
  • For posterior dislocations, reduction should be performed with the elbow flexed while providing distal traction.
  • Neurovascular status should be reassessed, followed by evaluation of stable range of elbow motion.
  • Postreduction radiographs are essential.
  • Postreduction management should consist of a posterior splint at 90 degrees and elevation.
  • Early, gentle, active range of elbow motion is associated with better long-term results. Prolonged immobilization is associated with unsatisfactory results and greater flexion contracture.
  • A hinged elbow brace through a stable arc of motion may be indicated in cases of instability without associated fracture.
  • Recovery of motion and strength may require 3 to 6 months.

Operative

  • When the elbow cannot be held in a concentrically reduced position, redislocates before postreduction radiography, or dislocates later in spite of splint immobilization, the dislocation is deemed unstable, and operative treatment is required.
  • There are three general approaches to this problem: (1) open reduction and repair of soft tissues back to the distal humerus, (2) hinged external fixation, or (3) cross-pinning of the joint.

Figure 59 (A) Parvinís method of closed reduction of an elbow dislocation. The patient lies prone on a stretcher, and the physician applies gentle downward traction of the wrist for a few minutes. As the olecranon begins to slip distally, the physician lifts up gently on the arm. No assistant is required, and if the maneuver is done gently, no anesthesia is required. (B) In Meyn and Quigleyís method of reduction, only the forearm hangs from the side of the stretcher. As gentle downward traction is applied on the wrist, the physician guides reduction of the olecranon with the opposite hand.

(A, redrawn from Parvin RW. Closed reduction of common shoulder and elbow dislocations without anesthesia. Arch Surg 1957;75:972-975. B, redrawn from Meyn MA, Quigley TB. Reduction of posterior dislocation of the elbow by traction on the dangling arm. Clin Orthop 1974;103:106-108.)

Elbow Fracture-Dislocations

Nonoperative

  • This is a reasonable treatment option in patients with dislocation and fracture of the radial head only.
  • Patients who elect nonoperative treatment need to be aware of the potential for instability and the substantial potential for restriction of motion or arthrosis from the radial head fracture.
  • Under close supervision, it is reasonable to remove the splint and to begin active motion at the patientís first visit to the office, typically about a week after injury.

Operative

  • This includes radial head resection, repair or replacement, and lateral collateral ligament repair.
  • If the radial head cannot be repaired, resection and replacement with a metal prosthesis will enhance immediate and long-term stability.
  • Most authors do not support acute collateral ligament reconstruction.
  • Some authors however, stress the importance of the lateral collateral ligament to elbow stability and advocate reattachment of this ligament to the lateral epicondyle.
  • When the lateral collateral ligament is repaired, immediate active motion is usually possible (particularly if radiocapitellar contact has also been restored), but up to 10 days of immobilization is reasonable.

Terrible Triad Fracture-Dislocations

  • The addition of a coronoid fracture, no matter how small, to a dislocation of the elbow and fracture of the radial head dramatically increases the instability and the potential for problems.
  • The term terrible triad of the elbow was coined by Hotchkiss to refer to this injury pattern.
  • Not all terrible triad injuries will be unstable, but it can be difficult to predict which injuries will be unstable.
  • Nonoperative treatment is risky because the elbow can dislocate in a cast, unknown to the patient.
  • Radial head resection without prosthetic replacement is unwise because recurrent dislocation of the elbow is common.
  • Good results have been reported with repair of the coronoid or anterior capsule, repair or replacement of the radial head, and lateral collateral ligament repair.
  • This restores stability in most cases, but in some patients MCL repair or hinged external fixation is also necessary.

COMPLICATIONS

  • Loss of motion (extension): This is associated with prolonged immobilization. Some authors recommend posterior splint immobilization for 3 to 4 weeks, although recent trends have been to begin early (1 week) range of elbow motion.
  • Neurologic compromise: Sustained neurologic deficits at the time of injury should be observed.
    • Spontaneous recovery usually occurs; a decline in nerve function (especially after manipulation) and severe pain in nerve distribution are indications for exploration and decompression.
    • Exploration is recommended if no recovery is seen after 3 months following electromyography.
  • Vascular injury: The brachial artery is most commonly disrupted during injury.
    • Prompt recognition of vascular injury is essential, with closed reduction to reestablish perfusion.
    • If, after reduction, perfusion is not reestablished, angiography is indicated to identify the lesion, with arterial reconstruction when indicated.
  • Compartment syndrome (Volkmann contracture): This may result from massive swelling due to soft tissue injury. Postreduction care must include elevation and avoidance of hyperflexion of the elbow. Serial neurovascular examinations and compartment pressure monitoring may be necessary, with forearm fasciotomy when indicated.
  • Instability/redislocation: This is rare after isolated, traumatic posterior elbow dislocation; the incidence is increased in the presence of an associated coronoid process and radial head fracture (terrible triad of the elbow). It may necessitate capsuloligamentous reconstruction, internal fixation, prosthetic replacement of the radial head, or hinged external fixation.
  • Heterotopic bone/myositis ossificans:
    • Anteriorly it forms between the brachialis muscle and the capsule; posteriorly it may form medially or laterally between the triceps and the capsule.
    • The risk is increased with multiple reduction attempts, a greater degree of soft tissue trauma, or the presence of associated fractures.
    • It may result in significant loss of function.
    • Forcible manipulation or passive stretching increases soft tissue trauma and should be avoided.
    • Indomethacin or local radiation therapy is recommended for prophylaxis after surgery and in the presence of significant soft tissue injury and/or associated fractures.

Hip Dislocations

EPIDEMIOLOGY

  • Up to 50% of patients sustain concomitant fractures elsewhere at the time of hip dislocation.
  • Unrestrained motor vehicle accident occupants are at a significantly higher risk for sustaining a hip dislocation than passengers wearing a restraining device.
  • Anterior dislocations constitute 10% to 15% of traumatic dislocations of the hip, with posterior dislocations accounting for the remainder.
  • Sciatic nerve injury is present in 10% to 20% of posterior dislocations (Fig. 60).

Figure 60. Left: Sciatic nerve impingement by the posteriorly dislocated femoral head. Right: Sciatic nerve impingement by a posterior acetabular fracture fragment in a posterior fracturedislocation of the hip.

(From Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 4th ed, vol. 1. Philadelphia: Lippincott-Raven, 1996:1756 with permission.)

 

ANATOMY

  • The hip articulation has a ball-and-socket configuration with stability conferred by bony and ligamentous restraints, as well as the congruity of the femoral head with the acetabulum.
  • The acetabulum is formed from the confluence of the ischium, ilium, and pubis at the triradiate cartilage.
  • Forty percent of the femoral head is covered by the bony acetabulum at any position of hip motion. The effect of the labrum is to deepen the acetabulum and increase the stability of the joint.
  • The hip joint capsule is formed by thick longitudinal fibers supplemented by much stronger ligamentous condensations (iliofemoral, pubofemoral, and ischiofemoral ligaments) that run in a spiral fashion, preventing excessive hip extension (Fig. 61).

Figure 61. The hip capsule and its thickenings (ligaments) as visualized from anteriorly (A) and posteriorly (B).

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

  • The main vascular supply to the femoral head originates from the medial and lateral femoral circumflex arteries, branches of the profunda femoral artery. An extracapsular vascular ring is formed at the base of the femoral neck with ascending cervical branches that pierce the hip joint at the level of the capsular insertion. These branches ascend along the femoral neck and enter the bone just inferior to the cartilage of the femoral head. The artery of the ligamentum teres, a branch of the obturator artery, may contribute blood supply to the epiphyseal region of the femoral head (Fig. 62).

Figure 62. Vascular anatomy of the femoral head and neck. Top: Anterior aspect. Bottom: Posterior aspect. LFC, lateral femoral circumflex artery.

(From Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 4th ed, vol. 2. Philadelphia: Lippincott-Raven, 1996:1662.)

  • The sciatic nerve exits the pelvis at the greater sciatic notch. A certain degree of variability exists in the relationship of the nerve with the piriformis muscle and short external rotators of the hip. Most frequently, the sciatic nerve exits the pelvis deep to the muscle belly of the piriformis.

MECHANISM OF INJURY

  • Hip dislocations almost always result from high-energy trauma, such as motor vehicle accident, fall from a height, or industrial accident. Force transmission to the hip joint occurs with application to one of three common sources:
    • The anterior surface of the flexed knee striking an object
    • The sole of the foot, with the ipsilateral knee extended
    • The greater trochanter
  • Less frequently, the dislocating force may be applied to the posterior pelvis with the ipsilateral foot or knee acting as the counterforce.
  • Direction of dislocation anterior versus posteriors determined by the direction of the pathologic force and the position of the lower extremity at the time of injury.

Anterior Dislocations

  • These comprise 10% to 15% of traumatic hip dislocations.
  • They result from external rotation and abduction of the hip.
  • The degree of hip flexion determines whether a superior or inferior type of anterior hip dislocation results:
    • Inferior (obturator) dislocation is the result of simultaneous abduction, external rotation, and hip flexion.
    • Superior (iliac or pubic) dislocation is the result of simultaneous abduction, external rotation, and hip extension.

Posterior Dislocations

  • They are much more frequent than anterior hip dislocations.
  • They result from trauma to the flexed knee (e.g., dashboard injury) with the hip in varying degrees of flexion:
    • If the hip is in the neutral or slightly adducted position at the time of impact, a dislocation without acetabular fracture will likely occur.
    • If the hip is in slight abduction, an associated fracture of the posterior-superior rim of the acetabulum usually occurs.

CLINICAL EVALUATION

  • Full trauma survey is essential because of the high-energy nature of these injuries. Many patients are obtunded or unconscious when they arrive in the emergency room as a result of associated injuries. Concomitant intraabdominal, chest, and other musculoskeletal injuries, such as acetabular, pelvic, or spine fractures, are common.
  • Patients presenting with dislocations of the hip typically are unable to move the lower extremity and are in severe discomfort.
  • The classic appearance of an individual with a posterior hip dislocation is a patient in severe pain with the hip in a position of flexion, internal rotation, and adduction. Patients with an anterior dislocation hold the hip in marked external rotation with mild flexion and abduction. The appearance and alignment of the extremity, however, can be dramatically altered by ipsilateral extremity injuries.
  • A careful neurovascular examination is essential, because injury to the sciatic nerve or femoral neurovascular structures may occur at time of dislocation. Sciatic nerve injury may occur with stretching of the nerve over the posteriorly dislocated femoral head. Posterior wall fragments from the acetabulum may also pierce or partially lacerate the nerve. Usually, the peroneal portion of the nerve is affected, with little if any dysfunction of the tibial nerve. Rarely, injury to the femoral artery, vein, or nerve may occur as a result of an anterior dislocation. Ipsilateral knee, patella, and femur fractures are common. Pelvic fractures and spine injuries may also be seen.

RADIOGRAPHIC EVALUATION

  • An anteroposterior (AP) radiograph of the pelvis is essential, as well as a cross-table lateral view of the affected hip.
  • On the AP view of the pelvis:
    • The femoral heads should appear similar in size, and the joint spaces should be symmetric throughout. In posterior dislocations, the affected femoral head will appear smaller than the normal femoral head. In anterior dislocation, the femoral head will appear slightly larger than the normal hip because of magnification of the femoral head to the x-ray cassette.
    • The Shenton line should be smooth and continuous.
    • The relative appearance of the greater and lesser trochanters may indicate pathologic internal or external rotation of the hip. The adducted or abducted position of the femoral shaft should also be noted.
    • One must evaluate the femoral neck to rule out the presence of a femoral neck fracture before any manipulative reduction.
  • A cross-table lateral view of the affected hip may help distinguish a posterior from an anterior dislocation.
  • Use of 45-degree oblique (Judet) views of the hip may be helpful to ascertain the presence of osteochondral fragments, the integrity of the acetabulum, and the congruence of the joint spaces. Femoral head depressions and fractures may also be seen.
  • Computed tomography (CT) scans are usually obtained following closed reduction of a dislocated hip. If closed reduction is not possible and an open reduction is planned, a computed tomography scan should be obtained to detect the presence of intra-articular fragments and to rule out associated femoral head and acetabular fractures.
  • The role of magnetic resonance imaging in the evaluation of hip dislocations has not been established; it may prove useful in the evaluation of the integrity of the labrum and the vascularity of the femoral head.

CLASSIFICATION

Hip dislocations are classified based on (1) the relationship of the femoral head to the acetabulum and (2) whether or not associated fractures are present.

 

Thompson and Epstein Classification of Posterior Hip Dislocations (Fig. 63)

Figure 63. Thompson and Epstein classification of posterior hip dislocations.

Type I:

Simple dislocation with or without an insignificant posterior wall fragment

Type II:

Dislocation associated with a single large posterior wall fragment

Type III:

Dislocation with a comminuted posterior wall fragment

Type IV:

Dislocation with fracture of the acetabular floor

Type V:

Dislocation with fracture of the femoral head

Epstein Classification of Anterior Hip Dislocations (Fig. 64)

Type I:

Superior dislocations, including pubic and subspinous

IA:

No associated fractures

IB:

Associated fracture or impaction of the femoral head

IC:

Associated fracture of the acetabulum

Type II:

Inferior dislocations, including obturator, and perineal

IIA:

No associated fractures

IIB:

Associated fracture or impaction of the femoral head

IIC:

Associated fracture of the acetabulum

 

Figure 64. Epstein classification of anterior hip dislocations.

(From Rockwood CA Jr, Green DP, eds. Rockwood and Greenís Fractures in Adults, 3rd ed. Philadelphia: Lippincott-Raven, 1996:1576 - 1579.)

 

 

OTA Classification of Hip Dislocations

See Fracture and Dislocation Compendium at http://www.ota.org/compendium/index.htm.

TREATMENT

  • One should reduce the hip on an emergency basis to decrease the risk of osteonecrosis of the femoral head; it remains controversial whether this should be accomplished by closed or open methods. Most authors recommend an immediate attempt at a closed reduction, although some believe that all fracture-dislocations should have immediate open surgery to remove fragments from the joint and to reconstruct fractures.
  • The long-term prognosis worsens if reduction (closed or open) is delayed more than 12 hours. Associated acetabular or femoral head fractures can be treated in the subacute phase.

Closed Reduction

Regardless of the direction of the dislocation, the reduction can be attempted with in-line traction with the patient lying supine. The preferred method is to perform a closed reduction using general anesthesia, but if this is not feasible, reduction under intravenous sedation is possible. There are three popular methods of achieving closed reduction of the hip:

ALLIS METHOD

This consists of traction applied in line with the deformity. The patient is placed supine with the surgeon standing above the patient on the stretcher. Initially, the surgeon applies in-line traction while the assistant applies countertraction by stabilizing the patientís pelvis. While increasing the traction force, the surgeon should slowly increase the degree of flexion to approximately 70 degrees. Gentle rotational motions of the hip as well as slight adduction will often help the femoral head to clear the lip of the acetabulum. A lateral force to the proximal thigh may assist in reduction. An audible clunk is a sign of a successful closed reduction (Fig. 65).

Figure 65. The Allis reduction technique for posterior hip dislocations.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

 

STIMSON GRAVITY TECHNIQUE

The patient is placed prone on the stretcher with the affected leg hanging off the side of the stretcher. This brings the extremity into a position of hip flexion and knee flexion of 90 degrees each. In this position, the assistant immobilizes the pelvis, and the surgeon applies an anteriorly directed force on the proximal calf. Gentle rotation of the limb may assist in reduction (Fig. 66).

Figure 66. The Stimson gravity method of reduction

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenís Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

 

BIGELOW AND REVERSE BIGELOW MANEUVERS

These have been associated with iatrogenic femoral neck fractures and are not as frequently used as reduction techniques. In the Bigelow maneuver, the patient is supine, and the surgeon applies longitudinal traction on the limb. The adducted and internally rotated thigh is then flexed at least 90 degrees. The femoral head is then levered into the acetabulum by abduction, external rotation, and extension of the hip. In the reverse Bigelow maneuver, used for anterior dislocations, traction is again applied in the line of the deformity. The hip is then adducted, sharply internally rotated, and extended.

  • Following closed reduction, radiographs should be obtained to confirm the adequacy of reduction. The hip should be examined for stability while the patient is still sedated or under anesthesia. If there is an obvious large displaced acetabular fracture, the stability examination need not be performed.
    • Stability is checked by flexing the hip to 90 degrees in neutral position. A posteriorly directed force is then applied. If any sensation of subluxation is detected, the patient will require additional diagnostic studies and possibly surgical exploration or traction.
    • Following successful closed reduction and completion of the stability examination, the patient should undergo CT evaluation.

Open Reduction

  • Indications for open reduction of a dislocated hip include:
    • Dislocation irreducible by closed means.
    • Nonconcentric reduction.
    • Fracture of the acetabulum or femoral head requiring excision or open reduction and internal fixation.
    • Ipsilateral femoral neck fracture.
  • A standard posterior approach (Kocher-Langenbeck) will allow exploration of the sciatic nerve, removal of posteriorly incarcerated fragments, treatment of major posterior labral disruptions or instability, and repair of posterior acetabular fractures.
  • An anterior (Smith-Peterson) approach is recommended for isolated femoral head fractures. A concern when using an anterior approach for a posterior dislocation is the possibility of complete vascular disruption. By avoiding removal of the capsule from the femoral neck and trochanters (i.e., taking down the capsule from the acetabular side), injury to the lateral circumflex artery or its branches should not occur.
  • An anterolateral (Watson-Jones) approach is useful for most anterior dislocations and combined fracture of both femoral head and neck.
  • A direct lateral (Hardinge) approach will allow exposure anteriorly and posteriorly through the same incision.
  • In the case of an ipsilateral displaced or nondisplaced femoral neck fracture, closed reduction of the hip should not be attempted. The hip fracture should be provisionally stabilized through a lateral approach. A gentle reduction is then performed, followed by definitive fixation of the femoral neck.
  • Management after closed or open reduction ranges from short periods of bed rest to various durations of skeletal traction. No correlation exists between early weight bearing and osteonecrosis. Therefore, partial weight bearing is advised.
    • If reduction is concentric and stable: A short period of bed rest is followed by protected weight bearing for 4 to 6 weeks.
    • If reduction is concentric but unstable: Skeletal traction for 4 to 6 weeks is followed by protective weight bearing.

PROGNOSIS

  • The outcome following hip dislocation ranges from an essentially normal hip to a severely painful and degenerated joint.
  • Most authors report a 70% to 80% good or excellent outcome in simple posterior dislocations. When posterior dislocations are associated with a femoral head or acetabular fracture, however, the associated fractures generally dictate the outcome.
  • Anterior dislocations of the hip are noted to have a higher incidence of associated femoral head injuries (transchondral or indentation types). The only patients with excellent results in most authors series are those without an associated femoral head injury.

COMPLICATIONS

  • Osteonecrosis: This is observed in 5% to 40% of injuries, with increased risk associated with increased duration of dislocation (>6 to 24 hours); however, some authors suggest that osteonecrosis may result from the initial injury and not from prolonged dislocation. Osteonecrosis may become clinically apparent up to 5 years after injury. Repeated reduction attempts may also increase its incidence.
  • Posttraumatic osteoarthritis: This is the most frequent long-term complication of hip dislocations; the incidence is dramatically higher when dislocations are associated with acetabular fractures or transchondral fractures of the femoral head.
  • Recurrent dislocation: This is rare (<2%), although patients with decreased femoral anteversion may sustain a recurrent posterior dislocation, whereas those with increased femoral anteversion may be prone to recurrent anterior dislocations.
  • Neurovascular injury: Sciatic nerve injury occurs in 10% to 20% of hip dislocations. It is usually caused by a stretching of the nerve from a posteriorly dislocated head or from a displaced fracture fragment. Prognosis is unpredictable, but most authors report 40% to 50% full recovery. Electromyographic studies are indicated at 3 to 4 weeks for baseline information and prognostic guidance. If no clinical or electrical improvement is seen by 1 year, surgical intervention may be considered. If a sciatic nerve injury occurs after closed reduction is performed, then entrapment of the nerve is likely and surgical exploration is indicated. Injury to the femoral nerve and femoral vascular structures has been reported with anterior dislocations.
  • Femoral head fractures: These occur in 10% of posterior dislocations (shear fractures) and in 25% to 75% of anterior dislocations (indentation fractures).
  • Heterotopic ossification: This occurs in 2% of patients and is related to the initial muscular damage and hematoma formation. Surgery increases its incidence. Prophylaxis choices include indomethacin for 6 weeks or use of radiation.
  • Thromboembolism: This may occur after hip dislocation owing to traction-induced intimal injury to the vasculature. Patients should be given adequate prophylaxis consisting of compression stockings, sequential compression devices, and chemoprophylaxis, particularly if they are placed in traction.

Knee Dislocation

EPIDEMIOLOGY

  • Traumatic knee dislocation is an uncommon injury that may be limb-threatening; it should therefore be treated as an orthopaedic emergency.
  • True incidence is probably underreported.
    • From 20% to 50% spontaneously reduce.
  • It is rare: at the Mayo Clinic, only 14 traumatic knee dislocations were observed in 2 million admissions. The largest series reported was from Los Angeles County Hospital, where over a 10-year period, 53 knee dislocations were seen.

ANATOMY

  • The ginglymoid (hinge joint) consists of three articulations: patellofemoral, tibiofemoral, and tibiofibular. Under normal cyclic loading, the knee may experience up to five times body weight per step. The normal range of motion is from 10 degrees of extension to 140 degrees of flexion with 8 to 12 degrees of rotation through the flexion-extension arc. The dynamic and static stability of the knee is conferred mainly by soft tissues (ligaments, muscles, tendons, menisci) in addition to the bony articulations.
  • Significant soft tissue injury is necessary for knee dislocation, including ruptures of at least three of four major ligamentous structures of the knee. The anterior and posterior cruciate ligaments (ACL and PCL) are disrupted in most cases, with a varying degree of injury to the collateral ligaments, capsular elements, and menisci.
  • The popliteal vascular bundle courses through a fibrous tunnel at the level of the adductor hiatus. Within the popliteal fossa, the five geniculate branches are given off, after which the vascular structures run deep to the soleus and through another fibrous canal. It is this tethering effect that leaves the popliteal vessels vulnerable to tenting and injury, especially at the moment of dislocation.
  • Associated fractures of the tibial eminence, tibial tubercle, fibular head or neck, and capsular avulsions are common and should be suspected.

MECHANISM OF INJURY

  • High-energy: A motor vehicle accident with a dashboard injury involves axial loading to a flexed knee.
  • Low-energy: This includes athletic injuries and falls.
  • Hyperextension with or without varus/valgus leads to anterior dislocation.
  • Flexion plus posterior force leads to posterior dislocation (dashboard injury).
    • Associated injuries include fractures of the femur, acetabulum, and tibial plateau.

CLINICAL EVALUATION

  • Patients present with gross knee distortion unless the knee underwent spontaneous reduction. Immediate reduction should be undertaken without waiting for radiographs. Of paramount importance is the arterial supply, with secondary consideration given to neurologic status.
  • Patients who sustain a knee dislocation that spontaneously reduces may have a relatively normal-appearing knee. Subtle signs of injury such as mild abrasions, or a minimal effusion, or complaints of knee pain may be the only abnormalities.
  • The extent of ligamentous injury is related to the degree of displacement, with injury occurring with displacement greater than 10% to 25% of the resting length of the ligament. Gross instability may be realized after reduction.
  • Isolated Ligament Examination
    • ACL
      • Lachman at 30 degrees
    • PCL
      • Posterior drawer at 90 degrees
    • Lateral collateral ligament (LCL)/Posterolateral corner (PLC)
      • Varus stress at 30 degrees and full extension
      • Increased tibial external rotation at 30 degrees
      • Increased posterior tibial translation at 30 degrees
    • Medial collateral ligament (MCL)
      • Valgus stress at 30 degrees
  • Combined Ligament Examination
    • LCL/PLC and cruciate
      • Increased varus in full extension and at 30 degrees
    • MCL and cruciate
      • Increased valgus in full extension and at 30 degrees
    • PLC and PCL
      • Increased tibial external rotation at 30 and 90 degrees
      • Increased posterior tibial translation at 30 and 90 degrees
    • Stability in full extension
      • Excludes significant PCL or capsular injury.
  • A careful neurovascular examination is critical, both before and after reduction, and serially thereafter, because vasospasm or thrombosis resulting from an unsuspected intimal tear may cause delayed ischemia hours or even days after reduction.
    • Vascular injury popliteal artery disruption (20% to 60%): The popliteal artery is at risk during traumatic dislocations of the knee owing to the bowstring effect across the popliteal fossa secondary to proximal and distal tethering. In a cadaveric study, hyperextension of the knee induced by anterior dislocation resulted in posterior capsular tearing at 30 degrees and popliteal artery tearing at 50 degrees. Although collateral circulation may result in the presence of distal pulses and capillary refill, it is inadequate to maintain limb viability.
    • The mechanism of arterial injury varies with the type of dislocation. When anterior dislocations injure the artery, it is usually by traction, resulting in an intimal tear. In contrast, vascular injuries associated with posterior dislocations are frequently complete arterial tears.
    • Vascular examination
      • Dorsalis pedis (DP) and posterior tibial (PT) artery pulses should be evaluated.
      • Pulse absent
        • Consider immediate closed reduction.
        • If still absent, proceed to the operating room for exploration.
        • If pulse returns, consider angiogram versus observation.
        • An 8-hour ischemic time is maximum.
      • Pulse present
        • If the ankle-brachial index (ABI) is >0.9, observe the patient.
        • If the ABI is <0.9, proceed with angiogram and/or exploration.
      • Vascular injuries: principles
        • Evaluate and document the vascular status (DP/PT pulses and capillary refill) in any patient with a proven or suspected knee dislocation.
        • Once the dislocation is reduced, the circulation should be reevaluated.
        • Revascularization should be performed within 8 hours.
        • Arteriography should not delay surgical reanastomosis.
        • It is unacceptable to suggest spasm as a cause for decreased or absent pulses in an attempt to justify observation.
        • If arterial insufficiency or abnormality is present, there is a vascular injury.
        • Arterial injury is treated with excision of the damaged segment and reanastomosis with a reverse saphenous vein graft.
        • An experienced vascular surgeon should be consulted to verify clinical findings and to interpret studies.
      • Vascular injuries: recommendations
        • Ischemic limb after reduction
          • Immediate surgical exploration is indicated.
          • Injury and location are predictable.
          • Arteriogram is indicated only if an additional associated proximal injury is present.
        • Abnormal vascular status: viable limb
          • Diminished pulses are noted.
          • Decreased capillary refill is seen.
          • The ABI is <0.9.
          • An urgent arteriogram is indicated.
        • Normal vascular status and no ligament or extremity surgery
          • PT/DP pulses and capillary refill are normal.
          • The ABI is >0.9.
          • Careful observation with serial examinations is warranted.
            • Vascular surgery and invasive radiology should be available.
          • Magnetic resonance angiography (MRA)/magnetic resonance imaging (MRI)
            • Evaluate for nonocclusive (intimal) injury.
            • Sensitivity and specificity are uncertain.
            • Arteriogram is indicated if results are abnormal.
        • Normal vascular status: potential or planned ligament or extremity surgery
          • PT/DP pulses and capillary refill are normal.
          • The ABI is >0.9.
          • Careful observation with serial examinations is indicated.
            • Vascular surgery and invasive radiology should be available.
          • MRA/MRI are part of the preoperative evaluation.
          • Routine arteriography is performed within 24 to 48 hours.
          • Intimal injury
            • Anticoagulation is administered.
            • No tourniquet is used.
            • Consider limited and delayed surgery (10 to 14 days).
            • No endoscopic PCL (tibial tunnel) is performed.
      • Neurologic injury peroneal nerve (10% to 35%): This is commonly associated with posterolateral dislocations, with injury varying from neurapraxia (usual) to complete transaction (rare). Primary exploration with grafting or repair is not effective; secondary exploration at 3 months is associated with poor results. Bracing and/or tendon transfer may be necessary for treatment of muscular deficiencies.

RADIOGRAPHIC EVALUATION

  • A knee dislocation is a potentially limb-threatening condition. Because of the high incidence of neurovascular compromise, immediate reduction is recommended before radiographic evaluation. Following reduction, anteroposterior (AP) and lateral views of the knee should be obtained to assess the reduction and evaluate associated injuries. Widened knee joint spaces may indicate soft tissue interposition and the need for open reduction.
  • Plain radiographs
    • AP and lateral
    • 45-degree oblique
    • Patellar sunrise
    • Findings
      • Obvious dislocation
      • Irregular/asymmetric joint space
      • Lateral capsular sign (Segond)
      • Avulsions
      • Osteochondral defects
  • The use of angiography in every case of knee dislocation is controversial. Vascular compromise is an indication for operative intervention. Identifying intimal tears in a neurovascularly intact limb may be unnecessary because most do not result in thrombosis and vascular occlusion. Some authors advocate selective arteriography only if the ABI is <0.9. Regardless, the patient should be closely observed for evidence of vascular insufficiency.
  • MRI
    • Indications: all knee dislocations and equivalents
    • Valuable diagnostic tool
      • Preoperative planning
      • Identification of ligament avulsions
      • MCL: injury location
      • Lateral structures: popliteus, LCL, biceps
      • Meniscal pathology
        • Displaced in notch an indication for early surgery
        • Limited arthroscopy secondary to extravasation
      • Articular cartilage lesions

CLASSIFICATION

Descriptive

This is based on displacement of the proximal tibia in relation to the distal femur. It also should include open versus closed, reducible versus irreducible. It may be classified as occult, indicating a knee dislocation with spontaneous reduction.

Anterior:

Forceful knee hyperextension beyond -30 degrees; most common (30% to 50%); associated with posterior (and possibly anterior) cruciate ligament tear, with increasing incidence of popliteal artery disruption with increasing degree of hyperextension

Posterior:

Posteriorly directed force against proximal tibia of flexed knee (25%); dashboard injury; accompanied by anterior and posterior ligament disruption as well as popliteal artery compromise with increasing proximal tibial displacement

Lateral:

Valgus force (13%); medial supporting structures disrupted, often with tears of both cruciate ligaments

Medial:

Varus force (3%); lateral and posterolateral structures disrupted

Rotational:

Varus/valgus with rotatory component (4%); usually results in buttonholing of the femoral condyle through the articular capsule

Anatomic Classification (Schenck, 1992)

I

Single cruciate + collateral

ACL + collateral
PCL + collateral

II

ACL/PCL

Collaterals intact

IIIM

ACL/PCL/MCL

LCL + PLC intact

IIIL

ACL/PCL/LCL + PLC

MCL intact

IV

ACL/PCL/MCL/LCL + PLC

 

V

          Fracture-dislocation

C

          Arterial injury

N

          Nerve injury

Utility of Anatomic Classification

  • It requires the surgeon to focus on what is torn.
  • It directs treatment to what is injured.
  • It leads to accurate discussion of injuries among clinicians.
  • Comparison of similar injuries can be made within the wide spectrum of knee dislocations.

TREATMENT

  • Immediate closed reduction is essential, even in the field and especially in the compromised limb. Direct pressure on the popliteal space should be avoided during or after reduction. Reduction maneuvers for specific dislocations:
    • Anterior: Axial limb traction is combined with lifting of the distal femur.
    • Posterior: Axial limb traction is combined with extension and lifting of the proximal tibia.
    • Medial/lateral: Axial limb traction is combined with lateral/medial translation of the tibia.
    • Rotatory: Axial limb traction is combined with derotation of the tibia.
  • The posterolateral dislocation is believed to be irreducible owing to buttonholing of the medial femoral condyle through the medial capsule, resulting in a dimple sign over the medial aspect of the limb; it requires open reduction
  • The knee should be splinted at 20 to 30 degrees of flexion. The knee must be perfectly reduced in the splint.
  • External fixation
    • This approach is better for the grossly unstable knee.
    • Protects vascular repair.
    • Permits skin care for open injuries.

General Treatment Considerations

  • Most authors recommend repair of the torn structures.
  • Nonoperative treatment has been associated with poor results.
  • Period of immobilization
    • A shorter period leads to improved motion and residual laxity.
    • A longer period leads to improved stability and limited motion.
  • Recent clinical series have reported better results with operative treatment.
  • No prospective, controlled, randomized trials of comparable injuries have been reported.
  • Once stiffness occurs, it is very difficult to treat.
  • Complete PLC disruption is best treated with early open repair.
    • Late reconstruction is difficult.
  • Reconstitution of the PCL is important.
    • It allows tibiofemoral positioning.
    • Collateral and ACL surgery evolves around PCL reconstitution.
    • ACL reconstruction before PCL treatment is never indicated.

Nonoperative

  • Immobilization in extension for 6 weeks
  • External fixation
    • Unstable or subluxation in brace
    • Obese patient
    • Multitrauma patient
    • Head injury
    • Vascular repair
    • Fasciotomy or open wounds
    • Removal of fixator under anesthesia
  • Arthroscopy
    • Manipulation for flexion
    • Assessment of residual laxity

Operative

  • Indications for operative treatment of knee dislocation include:
    • Unsuccessful closed reduction.
    • Residual soft issue interposition.
    • Open injuries.
    • Vascular injuries.
  • Vascular injuries require external fixation and vascular repair with a reverse saphenous vein graft from the contralateral leg; amputation rates as high as 86% have been reported when there is a delay beyond 8 hours with documented vascular compromise to limb. A fasciotomy should be performed at time of vascular repair for limb ischemia times longer than 6 hours.
  • Ligamentous repair is controversial: The current literature favors acute repair of lateral ligaments followed by early motion and functional bracing. Timing of surgical repair depends on the condition of both the patient and the limb. Meniscal injuries should also be addressed at the time of surgery.

Treatment Recommendations of Specific Patterns

  • ACL + MCL (class I knee dislocation)
    • MCL: predictable healing
    • Cylinder cast immobilization in extension for 2 weeks
    • Hinged brace permitting to range of motion
    • Delayed ACL reconstruction
      • Motion restored
      • Residual laxity and desired activity level
  • ACL + LCL/PLC (class I knee dislocation)
    • Delayed surgery at 14 days
      • Capsular healing
      • Identification of lateral structures
    • Arthroscopic ACL: femoral fixation
      • Instruments and experience with open techniques
      • Femoral fixation
    • Tibial fixation/ACL tensioned after LCL/PLC
    • Open posterolateral repair/reconstruction
  • ACL + PLC (class II knee dislocation)
    • Collateral ligaments intact
    • Hinged brace and early range of motion
      • Extension stop at 0 degrees
    • Arthroscopic reconstruction after 6 weeks
      • PCL only in most cases
      • ACL/PCL limited to high-demand patient
    • Sedentary individuals: no surgery
  • ACL + PLC + MCL (class IIIM knee dislocation)
    • Immobilization in extension
    • Early surgery (2 weeks)
      • Examination under anesthesia and limited diagnostic arthroscopy (MRI)
      • Single straight medial parapatellar incision
      • Open PCL reconstruction or repair
      • MCL repair
  • ACL + PLC + LCL/PLC (class IIIL knee dislocation)
    • Immobilization in extension
    • Delayed surgery at 14 days
      • Diagnostic arthroscopy
      • Arthroscopic or open PCL
      • Open LCL/PLC
    • Incisions critical: avoidance of the midline
      • PCL: medial (open or arthroscopic)
      • Straight posterolateral

COMPLICATIONS

  • Limited range of motion: This is most common, related to scar formation and capsular tightness. This reflects the balance between sufficient immobilization to achieve stability versus mobilization to restore motion. If it is severely limiting, lysis of adhesions may be undertaken to restore range of motion.
  • Ligamentous laxity and instability: Redislocation is uncommon, especially after ligamentous reconstruction and adequate immobilization.
  • Vascular compromise: This may result in atrophic skin changes, hyperalgesia, claudication, and muscle contracture. Recognition of popliteal artery injury is of paramount importance, particularly 24 to 72 hours after the initial injury, when late thrombosis related to intimal injury may be overlooked.
  • Nerve traction injury: Injury resulting in sensory and motor disturbances portends a poor prognosis, because exploration in the acute (<24 hours), subacute (1 to 2 weeks), and long-term settings (3 months) has yielded poor results. Bracing or muscle tendon transfers may be necessary to improve function.

 

PATELLA DISLOCATION

Epidemiology

  • Patellar dislocation is more common in women, owing to physiologic laxity, as well as in patients with hypermobility and connective tissue disorders (e.g., Ehlers-Danlos or Marfan syndrome).

Anatomy

  • The Q angle is defined as the angle subtended by a line drawn from the anterior superior iliac spine through the center of the patella, with a second line from the center of the patella to the tibial tubercle (Fig. 67). The Q angle ensures that the resultant vector of pull with quadriceps action is laterally directed; this lateral moment is normally counterbalanced by patellofemoral, patellotibial, and retinacular structures as well as patellar engagement within the trochlear groove. An increased Q angle predisposes to patella dislocation.

Figure 67. The Q (quadriceps) angle is measured from the anterior superior iliac spine through the patella and to the tibial tubercle.

(From Insall JN. Surgery of the Knee. New York: Churchill Livingstone, 1984.)

  • Dislocations are associated with patella alta, congenital abnormalities of the patella and trochlea, hypoplasia of the vastus medialis, and hypertrophic lateral retinaculum.

Mechanism of Injury

  • Lateral dislocation: Forced internal rotation of the femur on an externally rotated and planted tibia with knee in flexion is the usual cause. It is associated with a 5% risk of osteochondral fractures.
  • Medial instability is rare and usually iatrogenic, congenital, traumatic, or associated with atrophy of the quadriceps musculature.

Intra-articular dislocation: This is uncommon but may occur following knee trauma in adolescent male patients. The patella is avulsed from quadriceps tendon and is rotated around horizontal axis, with the proximal pole lodged in the intercondylar notch.

  • Superior dislocation: This occurs in elderly individuals from forced hyperextension injuries to the knee with the patella locked on an anterior femoral osteophyte.

Clinical Evaluation

  • Patients with an unreduced patella dislocation will present with hemarthrosis, an inability to flex the knee, and a displaced patella on palpation.
  • Lateral dislocations may also cause medial retinacular pain.
  • Patients with reduced or chronic patella dislocation may demonstrate a positive apprehension test, in which a laterally directed force applied to the patella with the knee in extension reproduces the sensation of impending dislocation, causing pain and quadriceps contraction to limit patella mobility.

Radiographic Evaluation

  • AP and lateral views of the knee should be obtained. In addition, an axial (sunrise) view of both patellae should be obtained. Various axial views have been described by several authors (Fig. 68):
    • Hughston 55 degrees of knee flexion: sulcus angle, patellar index
    • Merchant 45 degrees of knee flexion: sulcus angle, congruence angle
    • Laurin 20 degrees of knee flexion: patellofemoral index, lateral patellofemoral angle
  • Assessment of patella alta or baja is based on the lateral radiograph of the knee:
    • Blumensaat line: The lower pole of the patella should lie on a line projected anteriorly from the intercondylar notch on lateral radiograph with the knee flexed to 30 degrees.
    • Insall-Salvati ratio: The ratio of the length of the patellar ligament (LL; from the inferior pole of the patella to the tibial tubercle) to the patellar length (LP; the greatest diagonal length of the patella) should be 1.0. A ratio of 1.2 indicates patella alta, whereas 0.8 indicates patella baja (Fig. 69).

Figure 68. Representation of the (A) Hughston (knee flexed to 55 degrees) (B) Merchant (knee flexed to 45 degrees) and (C) Laurin (knee flexed to 20 degrees) patellofemoral views.

(From Bucholz RW, Heckman JD, eds. Rockwood and Greenís Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002.)

Figure 69. Insall-Salvati technique for measuring patellar height.

(From Insall NJ. Surgery New York: Churchill Livingstone, 1984.)

 

 

Classification

  • Reduced versus unreduced
  • Congenital versus acquired
  • Acute (traumatic) versus chronic (recurrent)
  • Lateral, medial, intraarticular, superior

Treatment

Nonoperative

  • Reduction and casting or bracing in knee extension may be undertaken with or without arthrocentesis for comfort.
  • The patient may ambulate in locked extension for 3 weeks, at which time progressive flexion can be instituted with physical therapy for quadriceps strengthening. After a total of 6 to 8 weeks, the patient may be weaned from the brace as tolerated.
  • Surgical intervention for acute dislocations is rarely indicated except in displaced intraarticular fractures.
  • Intraarticular dislocations may require reduction with the patient under anesthesia.
  • Functional taping has been described in the physical therapy literature with moderate success.

Operative

  • This is primarily used with recurrent dislocations.
  • No single procedure corrects all patellar malalignment problems; the patient‚Äôs age, diagnosis, level of activity, and condition of the patellofemoral articulation must be taken into consideration.
  • Patellofemoral instability should be addressed by correction of all malalignment factors.
  • Degenerative articular changes influence the selection of the realignment procedure.
  • Surgical interventions include:
    • Lateral release: Indicated for patellofemoral pain with lateral tilt, lateral retinacular pain with lateral patellar position, and lateral patellar compression syndrome. It may be performed arthroscopically or as an open procedure.

Medial plication: This may be performed at the time of lateral release to centralize patella.

Proximal patella realignment: Medialization of the proximal pull of the patella is indicated when a lateral release/ medial plication fails to centralize the patella. The release of tight proximal lateral structures and reinforcement of the pull of medial supporting structures, especially the vastus medialis obliquus, are performed in an effort to decrease lateral patellar tracking and improve congruence of the patellofemoral articulation. Indications include recurrent patellar dislocations that have not responded to nonoperative therapy and acute dislocations in young, athletic patients, especially with medial patellar avulsion fractures or radiographic lateral subluxation/tilt after closed reduction.

Distal patella realignment: Reorientation of the patellar ligament and tibial tubercle is indicated when an adult patient experiences recurrent dislocations and patellofemoral pain with malalignment of the extensor mechanism. This is contraindicated in patients with open physes and normal Q angles. It is designed to advance and medialize tibial tubercle, thus correcting patella alta and normalizing the Q angle.

Complications

  • Redislocation: The risk is higher in patients younger than 20 years at the time of the first episode. Recurrent dislocation is an indication for surgical intervention.
  • Loss of knee motion: This may result from prolonged immobilization. Surgical intervention may lead to scarring with resultant arthrofibrosis. This emphasizes the need for aggressive physical therapy to increase quadriceps tone to maintain patella alignment and to maintain knee motion.
  • Patellofemoral pain: This may result from retinacular disruption at time of dislocation or from chondral injury.

QUADRICEPS TENDON RUPTURE

  • Typically occurs in patients >40 years old.
  • It usually ruptures within 2 cm proximal to superior pole of patella.
  • Rupture level is often associated with the patientís age.
    • Rupture occurs at the bone-tendon junction in most patients >40 years old.
    • Rupture occurs at the midsubstance in most patients <40 years old.
  • Risk factors for quadriceps rupture
  • Tendinitis
    • Anabolic steroid use
    • Local steroid injection
    • Diabetes mellitus
    • Inflammatory arthropathy
    • Chronic renal failure
  • History
    • Sensation of a sudden pop while stressing the extensor mechanism
    • Pain at the site of injury
    • Inability/difficulty weight bearing
  • Physical examination
    • Knee joint effusion
    • Tenderness at the upper pole of patella
    • Loss of active knee extension
      • With partial tears, intact active extension
    • Palpable defect proximal to the superior pole of the patella
      • If defect present but patient able to extend the knee, then intact extensor retinaculum
      • If no active extension, then both tendon and retinaculum completely torn
  • Radiographic examination
    • AP, lateral, and tangential (Sunrise, Merchant)
    • Distal displacement of the patella
    • Blumensaat line
      • This is based on a lateral x-ray with the knee in 30 degrees of flexion.
      • The lower pole of the patella should be at the level of the line projected anteriorly from the intercondylar notch (Blumensaat line).
      • Patella alta possible with patellar tendon rupture and patella baja with quadriceps tendon rupture.
    • MRI or ultrasound
      • Useful for unclear diagnosis
  • Treatment
    • Nonoperative
      • Reserved for incomplete tears in which active, full knee extension is preserved.
      • The leg is immobilized in extension for approximately 4 to 6 weeks.
      • Progressive physical therapy may be required to regain strength and motion.
  • Operative
    • Indicated for complete ruptures.
    • Reapproximation of tendon to bone using nonabsorbable sutures passed through bone tunnels.
    • Repair the tendon close to the articular surface to avoid patellar tilting.
    • Midsubstance tears may undergo end-to-end repair after edges are freshened and slightly overlapped (Fig. 70).

Figure 70. Sequential steps of placing Krackow locking loop ligament sutures for tendon or ligament repair.

(From Krackow KA, Thomas SC, Jones LC. A new stitch for ligament tendon fixation: brief note. J Bone Joint Surg Am 1980;68:359.)

    • The patient may benefit from reinforcement from a distally based partial-thickness quadriceps tendon turned down across the repair site (Scuderi technique).
    • Chronic tears may require a V-Y advancement of a retracted quadriceps tendon (Codivilla V-Y-plasty technique).
  • Postoperative management
    • A knee immobilizer or cylinder cast is used for 5 to 6 weeks.
    • Immediate versus delayed (3 weeks) weight bearing is indicated as tolerated.
    • At 2 to 3 weeks, a hinged knee brace is used, starting with 45 degrees of active range of motion with 10 to 15 degrees of progression each week.
  • Complications
    • Rerupture
    • Persistent quadriceps atrophy/weakness
    • Loss of knee motion
    • Infection

PATELLA TENDON RUPTURE

  • Less common than quadriceps tendon rupture
  • Most common in patients <40 years old
  • Associated with degenerative changes of the tendon
  • Rupture common at the inferior pole of the patella
  • Risk factors
    • Rheumatoid arthritis
    • Systemic lupus erythematosus
    • Diabetes
    • Chronic renal failure
    • Systemic corticosteroid therapy
    • Local steroid injection
    • Chronic patella tendinitis
  • Anatomy of patellar tendon
    • Averages 4 mm thick but widens to 5 to 6 mm at the tibial tubercle
    • Merges with the medial and lateral retinaculum
    • Composition: 90% type I collagen
  • Blood supply
    • Fat pad vessels supply the posterior aspect of the tendon via the inferior medial and lateral geniculate arteries.
    • Retinacular vessels supply anterior portion of tendon via the inferior medial geniculate and recurrent tibial arteries.
    • Proximal and distal insertion areas are relatively avascular and subsequently are a common site of rupture.
  • Biomechanics
    • The greatest forces are at 60 degrees of knee flexion.
    • Forces through the patellar tendon are 3.2 times body weight while climbing stairs.
  • History
    • Often a report of forceful quadriceps contraction against a flexed knee
    • Possible audible pop
    • Inability to bear weight or extend the knee against gravity
  • Physical examination
    • Palpable defect
    • Hemarthrosis
    • Painful passive knee flexion
    • Partial or complete loss of active extension
    • Quadriceps atrophy with chronic injury
  • Radiographic examination
    • AP and lateral x-rays.
    • Patella alta visible on lateral view
      • Patella superior to Blumensaat line
    • Ultrasonography an effective means to determine continuity of the tendon
      • However, operator and reader dependent
    • MRI
      • Effective means to assess patella tendon, especially if other intraarticular or soft tissue injuries suspected
      • Relatively high cost
  • Classification
    • No widely accepted means of classification
    • Can be categorized by:
      • Location of tear
        • Proximal insertion most common
    • Timing between injury and surgery
      • Most important factor for prognosis
      • Acute: within 2 weeks
  • Treatment
    • Surgical treatment is required for restoration of the extensor mechanism.
    • Repairs are categorized as early or delayed.
  • Nonoperative
    • Nonoperative treatment is reserved for partial tears in which patient able to extend the knee fully.
    • Treatment is immobilization in full knee extension for 3 to 6 weeks.
  • Early repair
    • The overall outcome is better for a delayed repair.
    • Primary repair of the tendon is performed.
    • Surgical approach is through a midline incision.
    • Patellar tendon rupture and retinacular tears are exposed.
    • Frayed edges and hematoma are debrided.
    • Nonabsorbable sutures are used to repair the tendon to the patella.
    • Sutures are passed through parallel, longitudinal bone tunnels and are tied proximally.
    • Retinacular tears should be repaired.
    • One can reinforce the repair with wire, cable, or tape.
    • One should assess the repair intraoperatively with knee flexion.
  • Postoperative management
    • A hinged knee brace locked at 20 degrees.
    • Immediate isometric quadriceps exercises are prescribed.
    • Active flexion with passive extension occurs at 2 weeks; start with 0 to 45 degrees and advance 30 degrees each week.
    • Active extension occurs at 3 weeks.
    • Initial toe-touch weight bearing is gradually advanced to full weight bearing by 6 weeks.
    • Maintain a hinged knee brace, which is gradually increased as motion increases.
    • All restrictions are lifted after full range of motion and 90% of the contralateral quadriceps strength are obtained, usually at 4 to 6 months.
  • Delayed repair
    • This occurs >6 weeks from the initial injury.
    • It often results in a poorer outcome.
    • Quadriceps contraction and patellar migration are commonly encountered.
    • Adhesions between the patella and femur may be present.
    • Options include hamstring and fascia lata autograft augmentation of primary repair or Achilles tendon allograft.
    • Postoperative management
      • More conservative than with early repair.
      • A bivalved cylinder cast is worn for 6 weeks.
      • Active range of motion is started at 6 weeks.
  • Complications
    • Knee stiffness
    • Persistent quadriceps weakness
    • Rerupture
    • Infection
    • Patella baja

ACHILLES TENDON RUPTURE

Epidemiology

  • Most Achilles tendon problems are related to overuse injuries and are multifactorial.
  • The principal factors include host susceptibility and mechanical overload.
  • The spectrum of injury ranges from paratenonitis to tendinosis to acute rupture.
  • In a trauma setting, a true rupture is the most common presentation.
  • Delayed or missed diagnosis of Achilles tendon rupture by primary treating physicians is relatively common (up to 25%).

Anatomy

  • The Achilles tendon is the largest tendon in the body.
  • It lacks a true synovial sheath and instead has a paratenon with visceral and parietal layers permitting approximately 1.5 cm of tendon glide.
  • It receives its blood supply from three sources:
    • The musculotendinous junction.
    • The osseous insertion.
    • Multiple mesosternal vessels on the anterior surface of the tendon.

Clinical Evaluation

  • With either partial or complete Achilles tendon rupture, patients typically experience sharp pain, often described as feeling like being kicked in the leg.
  • With a partial rupture, physical examination may only reveal a localized, tender area of swelling.
  • With complete rupture, examination normally reveals a palpable defect in the tendon.
    • In this setting, the Thompson test is generally positive (i.e., squeezing the calf does not cause active plantar flexion), and the patient usually is incapable of performing a single heel-raise (Fig. 71).

Figure 71. The Thompson test for continuity of the gastrocnemius-soleus complex. Without rupture of the Achilles tendon, squeezing the calf causes active plantar flexion of the foot. With rupture, squeezing the superficial posterior compartment of the leg does not induce plantar flexion of the foot.

(Adapted from Browner B, Jupiter J, Levine A. Skeletal Trauma: Fractures, Dislocations, and Ligamentous Injuries, 2nd ed. Philadelphia: WB Saunders, 1997.)

    • The Thompson test can be falsely positive when the accessory ankle flexors (posterior tibialis, flexor digitorum longus, flexor hallucis longus muscles, or accessory soleus muscles) are squeezed together with the contents of the superficial posterior leg compartment.

Treatment

  • Goals are to restore normal musculotendinous length and tension and thereby to optimize ultimate strength and function of the gastrocnemius-soleus complex.
  • Whether operative or nonoperative treatment best achieves these goals remains a matter of controversy.
    • Proponents of surgical repair point to lower recurrent rupture rates, improved strength, and a higher percentage of patients who return to sports activities.
    • Proponents of nonoperative treatment stress the high surgical complication rates resulting from wound infection, skin necrosis, and nerve injuries.
    • When major complications, including recurrent ruptures, are compared, both forms of treatment have similar complication rates.
    • Most authors tend to treat active patients who are interested in continuing athletic endeavors with operative treatment and inactive patients or those with other complicating medical factors (e.g., immunosuppression, soft tissue injuries, history of recurrent lower extremity infections, vascular or neurologic impairment) with nonoperative approaches.
  • Nonoperative treatment begins with a period of immobilization.
    • Initially, the leg is placed in a splint for 2 weeks, with the foot in plantar flexion to allow hematoma consolidation.
    • Thereafter, a short or long leg cast is placed for 6 to 8 weeks, with less plantar flexion and progressive weight bearing generally permitted at 2 to 4 weeks after injury.
    • After removal of the cast, a heel lift is used while making the transition back to wearing normal shoes.
    • Progressive resistance exercises for the calf muscles are started at 8 to 10 weeks, with a return to athletic activities at 4 to 6 months.
    • Patients are informed that attainment of maximal plantar flexion power may take 12 months or more and that some residual weakness is common.
  • Surgical treatment is often preferred when treating younger and more athletic patients.
    • Several different operative techniques have been described, including percutaneous and open approaches.
    • Percutaneous approaches have the advantage of decreased dissection but have historically carried the disadvantages of potential entrapment of the sural nerve and an increased chance of inadequate tendon capture.
    • Open approaches have the intrinsic advantages of permitting complete evaluation of the injury and inspection of final tendon end reapproximation; however, they carry the disadvantages of higher rates of wound dehiscence and skin adhesion problems.
      • The surgical technique uses a medial longitudinal approach to avoid injury to the sural nerve.
      • The paratenon is carefully dissected, and sutures are placed in each tendon end for tendon reapproximation. The paratenon is closed in a separate layer.
    • Postoperative management consists of a partial weight bearing short leg cast for 6 to 8 weeks. This is followed by use of a 1-cm heel lift for 1 month. As with nonoperatively treated patients, progressive resistance exercises are started at 8 to 10 weeks, with a return to sports at 4 to 6 months.
    • With distal ruptures or sleeve avulsions, an open technique and reattachment of the tendon to the calcaneus is performed. This is usually done with transosseous suture fixation.