IThoracic And Lumbar Spine Fractures

O Edward A. Smirnov, MD, D. Greg Anderson, MD, Todd J. Albert, MD, and Vincent J. Devlin, MD

1. Why is it important to assess radiographically the entire spinal axis when a significant spine fracture is identified in one region of the spine?

There is a 5% to 20% chance that a patient has a second fracture in a different region of the spine. Factors that increase the risk of missed spine fractures on initial evaluation include head injuries, intoxication, drug use, and polytrauma.

2. What factors increase the risk of neurologic injury with thoracic and lumbar spine fractures?

1. High-energy injuries, especially burst fractures and fracture dislocations

2. Fractures located above the L2 level. The conus medullaris and spinal cord occupy the spinal canal in this location, and these neural elements are more prone to neurologic injury than the nerve roots of the cauda equina

3. Are plain radiographs sufficient to distinguish the common types of thoracic and lumbar spine fractures?

No! Although anteroposterior (AP) and lateral radiographs are the best first imaging test to assess a spine fracture, a computed tomography (CT) scan must be obtained when radiographs suggest a significant thoracic or lumbar fracture. Failure to obtain a CT scan may lead to inappropriate diagnosis and treatment. Magnetic resonance imaging (MRI) plays a complementary role and is useful in the assessment of patients with neurologic deficit and for evaluation of the posterior ligamentous complex (PLC).

4. What parameters are important to assess on radiographs of thoracic and lumbar fractures? (Fig. 57-1)

• Percentage of vertebral body compression: The anterior vertebral height (B) is divided by the posterior vertebral height (A) or the height of an adjacent non-fractured vertebra and multiplied by 100.

• Local kyphotic deformity: The angle (C) between the vertebral endplates above and below the injured level is determined (Cobb method). This value (kyphosis angle) is compared with the normal sagittal alignment for the specific levels of the spine under evaluation.

• Integrity of the posterior spinal column: Findings that suggest disruption of the posterior spinal column include widening or splaying of the spinous processes or a localized kyphotic deformity of a thoracolumbar spinal segment.

• Signs of major spinal column disruption: Relative distraction, translation, or rotational displacement of adjacent vertebrae implies a severe injury with disruption of all three spinal columns.

5. Define the three-column model of the spine as described by Denis (Fig. 57-2).

• The anterior column is composed of the anterior longitudinal ligament, anterior half of the vertebral body, and anterior half of the disc

• The middle column is composed of the posterior half of the vertebral body, the posterior half of the disc, and the posterior longitudinal ligament

• The posterior column includes the pedicles, facet joints, lamina, and posterior ligament complex

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Figure 57-1. Useful radiographic parameters for assessing thoracic and lumbar fractures: (1) percentage of vertebral body compression, (2) local kyphotic deformity, and (3) disruption of the posterior spinal column. Percentage of vertebral body compression is determined by dividing the anterior vertebral height (B) by the posterior vertebral height (A). The local kyphotic deformity is determined by measuring the angle (C) between the vertebral endplates above and below the injured level.

Figure 57-1. Useful radiographic parameters for assessing thoracic and lumbar fractures: (1) percentage of vertebral body compression, (2) local kyphotic deformity, and (3) disruption of the posterior spinal column. Percentage of vertebral body compression is determined by dividing the anterior vertebral height (B) by the posterior vertebral height (A). The local kyphotic deformity is determined by measuring the angle (C) between the vertebral endplates above and below the injured level.

Figure 57-2. Denis' three-column model of the spine. The middle column is made up of the posterior longitudinal ligament, the posterior annulus fibrosis, and the posterior aspects of the vertebral body and disc. (Lee YP, Templin C, Eismont F, et al. Thoracic and upper lumbar trauma. In: Browner BD, Jupiter Jb, Levine AM, et al., editors. Skeletal Trauma, 4th ed. Philadelphia: Saunders; 2008.)

Posterior

Posterior

Figure 57-2. Denis' three-column model of the spine. The middle column is made up of the posterior longitudinal ligament, the posterior annulus fibrosis, and the posterior aspects of the vertebral body and disc. (Lee YP, Templin C, Eismont F, et al. Thoracic and upper lumbar trauma. In: Browner BD, Jupiter Jb, Levine AM, et al., editors. Skeletal Trauma, 4th ed. Philadelphia: Saunders; 2008.)

6. What are the six most common patterns of thoracolumbar fractures described by McAfee?

McAfee expanded Denis's concepts and classified thoracic and lumbar spine fractures into six patterns based on CT scan analysis. Injury patterns were determined based on the forces (compression, axial distraction or translation) that disrupt the middle spinal column (Fig. 57-3) (Table 57-1).

Figure 57-3. McAfee classification of thoracic and lumbar fractures. A, Compression fracture. B, Stable burst fracture. C, Unstable burst fracture. D, Chance fracture. E, Flexion-distraction injury. F, Fracture-dislocation or translational injury.

Table 57-1. The McAfee Classification of Thoracic and Lumbar Fractures

MODE OF SPINAL COLUMN FAILURE

FRACTURE TYPE

ANTERIOR

MIDDLE

POSTERIOR

INJURY MECHANISM

Compression

Compression

Intact

Intact

Axial load, flexion

Stable Burst

Compression

Compression

Intact

Compression

Unstable Burst

Compression

Compression

Compression, lateral flexion, or rotation

Compression, lateral flexion, rotation

Flexion-Distraction

Compression

Tension

Tension

Flexion-distraction

Chance

Tension

Tension

Tension

Tension

Translational (Fracture-Dislocation)

Shear, Rotation

Shear, Rotation

Shear, Rotation

Shear, rotation

7. Discuss limitations regarding classification systems for thoracic and lumbar spine fractures.

A wide variety of classification schemes have been proposed including the AO/Magerl classification, the Denis classification, the McAfee classification, and the Load-Sharing classification.

• The AO/Magerl classification identifies three primary injury patterns: compression, distraction, and torsion. However, these injuries are subdivided into more than 50 distinct injury patterns, which makes application of this classification challenging in clinical practice.

• Similarly, the Denis classification proposed four main fracture types—compression, seat-belt, burst, and fracture-dislocations—but described more than 16 injury subtypes. Its complexity and the discovery that the middle spinal column plays a secondary role in determining spinal instability have stimulated additional research.

• The McAfee classification provides sufficient detail to place injuries into six distinct categories and facilitates communication with the multidisciplinary team involved in trauma care.

• The Load-Sharing classification provides valuable guidance in determining an appropriate surgical approach for thoracolumbar fracture repair.

However, the previous classifications do not stratify neurologic injury, do not define spinal instability, fail to incorporate MRI data, and lack guidelines for nonoperative versus operative treatment. Such limitations have led to ongoing research to develop a comprehensive, valid, user-friendly classification to guide treatment. The Thoracolumbar Injury Classification and Severity Score (TLICS) has recently been introduced to address these issues. This score is based on three factors:

• Injury mechanism

• Neurologic status

• Integrity of the posterior ligamentous complex (PLC)

A score of 3 or less suggests nonoperative treatment; a score of 4 suggests nonoperative or operative treatment; and a score of 5 or greater suggests operative treatment. Point values are assigned to each factor as follows:

• Injury mechanism: compression fracture (1), burst fracture (2), translational-rotational injury (3), distraction injury (4)

• Neurologic status: Intact (0), nerve root injury (2), incomplete cord/conus injury (3), complete cord/conus injury (2), cauda equina injury (3)

• PLC status: Intact (0), indeterminate (2), disrupted (3)

COMPRESSION FRACTURES

8. Describe the mechanism, injury pattern, and treatment of a thoracic or lumbar compression fracture.

Compression fractures represent an isolated failure of the anterior spinal column due to a combination of flexion and axial compression loading (Fig. 57-4). Because the structural stability of the spine is not compromised by this single-column injury, treatment consists of early patient mobilization. Typically the patient is treated with an orthosis (e.g. Jewett brace, thoracolumbosacral orthosis [TLSO]) until back pain resolves. Radiographic and clinical follow-up is generally carried out on a monthly basis for the first 3 months after injury.

Figure 57-4. Compression fracture. A, Lateral radiograph. B, Axial computed tomography scan. A compression fracture represents an injury of the anterior spinal column. Note the loss of anterior vertebral height. Treatment with an orthosis led to complete resolution of symptoms within 2 months.

9. What radiographic features are considered worrisome when assessing compression fractures?

• Loss of vertebral height exceeding 50% (suggests possible posterior ligamentous injury)

• Segmental kyphosis exceeding 20° (suggests possible posterior ligamentous injury)

• Multiple adjacent compression fractures (may require surgical treatment if significant kyphotic deformity occurs)

• Loss of the pedicle shadow on the anteroposterior (AP) radiograph or presence of a soft tissue mass on MRI (suggests possibility of a pathologic fracture secondary to tumor or infection)

10. Why is a compression fracture with greater than 40% to 50% loss of anterior vertebral body height considered unstable?

Because it is highly likely that an associated posterior ligament complex disruption is present. The posterior ligament complex experiences about one third of the tensile load transmitted to the vertebral body to cause fracture. In young persons with good bone quality, the magnitude of the load required to create a compression fracture may result in tensile failure of the posterior ligamentous complex.

11. Outline the treatment of compression fractures secondary to osteoporosis.

Osteoporotic compression fractures are usually due to low-energy trauma in patients with weakened bone. They are common in the elderly, as well as patients on chronic steroid therapy. Multiple fractures may occur and may lead to significant spinal deformities and/or pain. It is important to rule out pathologic fracture due to tumor (e.g. multiple myeloma, metastatic disease) or metabolic bone disease (e.g. osteomalacia). Fracture treatment depends on severity and location of injury. Most fractures can be managed with an orthosis. It is important to diagnose and treat the underlying osteoporosis in addition to treating the fracture. Baseline bone density studies of the spine and hip should be performed. Osteoporosis treatment options include exercise, hormone replacement therapy, bisphosphonate therapy, calcitonin, or teriparatide. Open surgical treatment with spinal canal decompression combined with stabilization and fusion is generally reserved for fractures associated with neurologic deficit. Minimally invasive surgical procedures such as vertebroplasty and kyphoplasty have been popularized for the treatment of select acute and subacute compression fractures. These procedures attempt to relieve pain by supplementing the structural integrity of the collapsed vertebral body via the injection of polymethylmethacrylate (PMMA) bone cement.

STABLE BURST FRACTURES

12. Describe the mechanism and injury pattern associated with a stable burst fracture.

Key features that identify a stable burst fracture (Fig. 57-5) include:

• Fracture involves the anterior and middle spinal columns

• Height loss of the vertebral body is present

• Posterior vertebral body cortex is disrupted

• Facet joints and lamina do not demonstrate any displaced fractures

• Preservation of posterior spinal column integrity (absence of widening between the spinous processes at the fracture level when compared with adjacent spinal levels)

• The patient has intact neurologic status n

Figure 57-5. Stable L1 burst fracture. This fracture involves the anterior and middle spinal columns. Note the disruption of the posterior vertebral body cortex. The posterior spinal column is not disrupted. A, Lateral radiograph. B, Anteroposterior radiograph. C, Sagittal computed tomography (CT). D, Axial CT. Treatment with a thoracolumbosacral orthosis led to resolution of symptoms.

Although bone may be retropulsed into the spinal canal, the resultant compromise of the spinal canal is less than 50%. Loss of anterior column vertebral height is less than 50%. The local kyphotic deformity is generally less than 15° to 25°. Despite the possible presence of a nondisplaced vertical fracture in the lamina, the facet joints and the posterior ligament complex remain intact.

13. What are the treatment options for a stable burst fracture?

Stable burst fractures are usually treated by nonoperative techniques. An excellent method is closed reduction and body-cast immobilization. Immobilization in a TLSO is the most common method used currently. A cervical extension is added for fractures above T7, and a thigh cuff is considered for low lumbar fractures (L4, L5). The cast or brace is generally worn for 3 months.

14. What percent of burst fractures is misdiagnosed as compression fractures on plain radiographs?

Approximately 25% of burst fractures are misdiagnosed as compression fractures if radiographs alone are evaluated. For this reason, it is important to evaluate significant thoracic and lumbar spine fractures with a CT scan.

15. What radiographic criteria help to distinguish a burst fracture from a compression fracture?

Loss of posterior vertebral body height (compared with the vertebrae above and below), any break in the posterior aspect of the vertebral body, or interpedicular widening on the AP view are signs of a burst fracture. The posterior vertebral body angle may aid diagnosis. This angle is formed by a line drawn along the vertebral endplate and the posterior vertebral body margin. If this angle is greater than 100°, a burst fracture is likely present.

UNSTABLE BURST FRACTURES

16. Describe the mechanism and injury pattern of an unstable burst fracture.

Unstable burst fractures result from axial compression forces that disrupt all three columns of the spine. The anterior and middle columns fail in compression with loss of vertebral body height and retropulsion of the posterior vertebral body wall into the spinal canal. The AP radiograph shows a widening of the distance between the pedicles at the level of fracture. Unlike a stable burst fracture, the posterior ligamentous complex (PLC) is disrupted. Posterior spinal column disruption permits development of a kyphotic deformity. CT scans are used to determine the percentage of spinal canal compromise and the presence or absence of an associated laminar fracture.

17. What is the major concern about a burst fracture associated with a laminar fracture?

Possible incarceration of the dura or neural elements in the fracture site with associated cerebrospinal (CSF) leakage may be present. One study demonstrated incarceration of the dural sac in the fracture site in more than one third of burst fractures associated with a laminar fracture.

18. What nonspinal injuries are commonly associated with burst fractures?

Calcaneus fractures, long bone fractures, and closed head injuries.

19. What are the major criteria for recommending nonsurgical treatment for burst fractures?

Burst fractures without neurologic deficit, with canal compromise less than 50%, and with less than 30° of initial kyphosis may be considered for nonsurgical treatment. Such patients require close clinical and radiographic monitoring for the potential development of neurologic deficit and progressive kyphotic deformity.

20. What are the major criteria for recommending surgical treatment for burst fractures?

Indications for surgical treatment of burst fractures are controversial and include:

• Progressive neurologic deficit

• CT evidence of spinal canal compromise associated with incomplete neurologic deficit

• Burst fracture associated with significant disruption of the posterior column—for example, facet subluxation, significant disruption of the posterior ligamentous complex

• Greater than 50% loss of vertebral body height

• Kyphosis greater than 25° to 30° at the level of fracture

• Inability to immobilize the patient with a brace due to associated injuries or body habitus See Figure 57-6.

Figure 57-6. Unstable burst fracture. Treatment with long segment fixation. A 43-year-old man sustained a T12 burst fracture when a mobile home roof fell on him during a storm. The patient was neurologically intact. A, A preoperative anteroposterior (AP) radiograph shows approximately 50 percent loss of height at T12 and L1. B, A preoperative lateral view shows local kyphosis measuring 27°. C, Axial computed tomography shows a minimal burst component at L1.

Continued y

Figure 57-6. Unstable burst fracture. Treatment with long segment fixation. A 43-year-old man sustained a T12 burst fracture when a mobile home roof fell on him during a storm. The patient was neurologically intact. A, A preoperative anteroposterior (AP) radiograph shows approximately 50 percent loss of height at T12 and L1. B, A preoperative lateral view shows local kyphosis measuring 27°. C, Axial computed tomography shows a minimal burst component at L1.

Continued

Figure 57-6, cont'd. D, This injury was stabilized with posterior pedicle screws and rods. E, Postoperative AP radiograph showing two cross-connectors used for additional stability. (Lee YP, Templin C, Eismont F, et al. Thoracic and upper lumbar trauma. In: Browner BD, Jupiter JB, Levine AM, et al, editors. Skeletal Trauma. 4th ed. Philadelphia: Saunders; 2008.)

21. What are the surgical goals in treating unstable burst fractures?

• Decompression: Spinal canal decompression is generally indicated for patients with neurologic deficits, especially incomplete deficits. Neurologic assessment should include lower extremity sensory and motor function, as well as bowel and bladder function

• Realignment: Spinal realignment is achieved through use of spinal instrumentation with correction of kyphotic deformity

• Stabilization: The combination of spinal instrumentation and spinal fusion can restore long-term stability to injured spinal segments

22. What are three options for decompression of spinal canal stenosis resulting from a burst fracture in a patient with a neurologic deficit?

• Indirect decompression: Distraction applied to the fracture through the use of posterior spinal instrumentation has the potential to reduce the fracture fragments and decompress the spinal canal through ligamentotaxis. This technique is most likely to be successful if performed within the first 72 hours after the fracture occurs

• Direct posterolateral decompression: The fragments impinging on the neural elements are pushed away anteriorly to decompress the dural sac after exposure of the spinal canal is achieved through a laminectomy or transpedicular approach. This procedure is performed in conjunction with posterior spinal instrumentation and fusion

• Direct anterior decompression: The fracture may be exposed directly through an anterior approach, and the entire vertebral body may be removed (corpectomy) to decompress the spinal canal. A bone graft or cage is used to reconstruct the anterior spinal column. Spinal stability is restored by placement of anterior spinal instrumentation, posterior spinal instrumentation, or a combination of both anterior and posterior spinal implants

See Figure 57-7.

Figure 57-7. Unstable burst fracture. L1 burst fracture treated with posterior pedicle screw fixation followed by anterior decompression and reconstruction using structural allograft. The preoperative lateral radiograph (A) and computed tomography (CT) scan (B) demonstrate 60% loss of vertebral body height and 90% spinal canal occlusion. C, CT following urgently performed posterior decompression and short segment fixation demonstrate approximately 50% residual canal compromise. The lateral (D) and anteroposterior (E) radiographs demonstrate tibial allograft placement after anterior decompression. This second surgery was performed 10 days after the posterior procedure. The patient sustained multiple injuries following a high-speed motorcycle accident. (From Chapman JR, Mirza SK. Anterior treatment of thoracolumbar fractures. Spine State Art Rev 1998;12:647-61.)

Figure 57-7. Unstable burst fracture. L1 burst fracture treated with posterior pedicle screw fixation followed by anterior decompression and reconstruction using structural allograft. The preoperative lateral radiograph (A) and computed tomography (CT) scan (B) demonstrate 60% loss of vertebral body height and 90% spinal canal occlusion. C, CT following urgently performed posterior decompression and short segment fixation demonstrate approximately 50% residual canal compromise. The lateral (D) and anteroposterior (E) radiographs demonstrate tibial allograft placement after anterior decompression. This second surgery was performed 10 days after the posterior procedure. The patient sustained multiple injuries following a high-speed motorcycle accident. (From Chapman JR, Mirza SK. Anterior treatment of thoracolumbar fractures. Spine State Art Rev 1998;12:647-61.)

23. What are the advantages and disadvantages of using pedicle screws for treatment of thoracolumbar burst fractures?

Advantages:

• Emergent decompression and short-segment instrumentation and fusion can be expeditiously performed and permits early patient mobilization.

• Fewer spine segments require instrumentation and fusion when pedicle screws are used, compared with when rod and hook constructs are utilized.

• Pedicle screws can be used with contoured rods to maintain and restore normal sagittal alignment.

Disadvantages:

• Second-stage anterior corpectomy and fusion may be required in fractures with extensive vertebral body comminution because pedicle screw constructs without anterior column structural support are prone to screw breakage

• Patients with residual cord/root compression in the setting of persistent neurologic deficit will require delayed anterior decompression and fusion

24. What are the common indications for use of an anterior approach and anterior instrumentation in a thoracolumbar burst fracture?

Indications include fractures from T11 to L3, especially when an incomplete neurologic lesion with compromise of the spinal canal would benefit from direct decompression of the spinal canal. Significant kyphotic deformities in which anterior column structural grafting is indicated also respond well to an anterior approach (Fig. 57-8).

Figure 57-8. Unstable burst fracture. L1 burst fracture treated with corpectomy, anterior femoral allograft, and anterior rod-screw construct (Kaneda instrumentation). A, Preoperative lateral radiograph. B, Preoperative sagittal MRI. Postoperative C, anteroposterior and D, lateral radiographs. (From Devlin VJ, Pitt DD. The evolution of surgery of the anterior spinal column. Spine State Art Rev 1998; 12:493-527.)

Figure 57-8. Unstable burst fracture. L1 burst fracture treated with corpectomy, anterior femoral allograft, and anterior rod-screw construct (Kaneda instrumentation). A, Preoperative lateral radiograph. B, Preoperative sagittal MRI. Postoperative C, anteroposterior and D, lateral radiographs. (From Devlin VJ, Pitt DD. The evolution of surgery of the anterior spinal column. Spine State Art Rev 1998; 12:493-527.)

25. Discuss the major limitations of an anterior approach to thoracolumbar burst fractures.

Fractures below L3 are difficult to treat with anterior instrumentation because of local anatomic constraints due to the proximity of the aorta, vena cava, and iliac vessels. Anterior corpectomy for acute fractures is frequently accompanied by significant bleeding from the fractured vertebra. There is limited ability to realign the spine from an anterior approach in the presence of posttraumatic translational or scoliotic deformities, and such injuries are more effectively treated with initial posterior instrumentation. It is not possible to explore lamina fractures noted on CT scan for potential incarceration of the dura with associated CSF leak from the anterior approach. Care must be taken in cases with significant disruption of the posterior column, and patients with osteoporotic bone as the anterior screw fixation may not provide adequate stability in these cases. Noncompliant/combative patients represent additional contraindications to anterior-only approaches. These patients require the added stability of posterior instrumentation because they will be noncompliant with postoperative brace wear.

CHANCE FRACTURES

26. Describe the mechanism and injury pattern of a Chance fracture.

Chance fractures generally result from a flexion injury mechanism in a lap-belt-restrained car passenger. Radiographs show three spinal columns injured transversely due to failure of the spinal segment in tension. The axis of rotation for this injury is anterior to the vertebral body. The disruption of the spine may progress through bone (vertebral body, pedicle, and spinous process), soft tissue (disc, facet joint, and interspinous ligament), or a combination of bone and soft tissue structures.

27. What nonspinal injuries are commonly associated with Chance fractures?

A high incidence of intraabdominal (bowel) injury (45%) is associated with Chance fractures.

28. What are the treatment options for a Chance fracture?

In general, patients with Chance fractures are treated with posterior spinal instrumentation and fusion (Fig. 57-9). A short-segment posterior instrumentation construct, which applies compression forces across the fracture, is appropriate. The pattern of injury determines the minimum number of levels requiring instrumentation. If the injury to the middle column involves the posterior disc, MRI is indicated to identify a disc herniation that may require excision prior to application of posterior compression forces. Uncommonly, patients who sustain injuries entirely through bone and do not have concomitant abdominal or neurologic injuries may be treated with extension casting.

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Figure 57-9. Chance fracture. A, Anteroposterior radiograph. B, Lateral radiograph. C, Postoperative lateral radiograph. D, Postoperative anteroposterior radiograph. (From Puno RM, Bhojraj SY, Glassman SD, et al. Flexion distraction injuries of the thoracolumbar and lumbar spine in the adult and pediatric patient. Spine State Art Rev 1993;7:223-48.)

Figure 57-9. Chance fracture. A, Anteroposterior radiograph. B, Lateral radiograph. C, Postoperative lateral radiograph. D, Postoperative anteroposterior radiograph. (From Puno RM, Bhojraj SY, Glassman SD, et al. Flexion distraction injuries of the thoracolumbar and lumbar spine in the adult and pediatric patient. Spine State Art Rev 1993;7:223-48.)

FLEXION-DISTRACTION INJURIES

29. Describe the mechanism and injury pattern of a flexion-distraction injury.

Common injury mechanisms for flexion-distraction injuries include motor vehicle accidents and falls from a height. Such injuries result in tensile failure of the posterior spinal column and compressive failure of the anterior column and possibly the middle column. Posterior column injuries include separation of the spinous processes and facet joints. The vertebral body is wedged anteriorly (see Fig. 57-10). Bony fragments from the middle column may be retropulsed into the spinal canal. The axis of rotation for a flexion-distraction injury is within the vertebral body, in contrast to a Chance fracture where the axis of rotation is located anterior to the vertebral body. A flexion-distraction injury may be misdiagnosed initially as a compression fracture if the disruption of the posterior spinal column is unrecognized.

30. What are the treatment options for a flexion-distraction injury?

These unstable injuries are treated with posterior spinal instrumentation and posterior fusion (see Fig. 57-10).

Figure 57-10. Flexion-distraction injury. A, Preoperative an-teroposterior (AP) radiograph. B, Preoperative lateral radiograph. C, Preoperative computed tomography scan. D, Postoperative AP radiograph. E, Postoperative lateral radiograph. (From Holt BT, McCormack T, Gaines RW Jr. Short-segment fusion: Anterior or posterior approach? Spine State Art Rev 1993;7:277-86.)

TRANSLATIONAL INJURIES (FRACTURE-DISLOCATIONS)

31. Describe the mechanism and injury pattern of a translational injury (fracture-dislocation).

Fracture-dislocations result from high-energy injuries and are the most unstable type of spine fractures. The structural integrity of all three spinal columns is completely disrupted with resultant displacement of the spine in one or more planes (Fig. 57-11). Severe neurologic deficits generally accompany this injury pattern.

Figure 57-11. Translational injury. A, Preoperative lateral radiograph. B, Axial computed tomography (CT) image. C, Sagittal CT image. D, Postoperative anteroposterior radiograph. E, Postoperative lateral radiographs.

32. What are the treatment options for a translational injury (fracture-dislocation)?

These injuries require surgical stabilization regardless of the patient's neurologic status. These injuries are best treated initially from a posterior approach to realign the spine and restore spinal stability by fixation two or three levels above and below the injury. Anterior column reconstruction may be indicated if there is severe comminution precluding achievement construct stability with isolated posterior instrumentation or if spinal canal decompression is required (especially for patients with incomplete neurologic deficits) (see Fig. 57-11).

GUNSHOT INJURIES TO THE SPINE

33. How does the treatment of thoracolumbar injuries due to gunshot wounds differ from other mechanisms of injury?

Gunshot injuries generally spare the spinal ligaments, and thus most gunshot injuries are mechanically stable. However, many patients may have a neurologic deficit resulting from the blast wound to the neurologic elements. Most patients can be treated nonoperatively and mobilized in a TLSO. Tetanus prophylaxis should be considered. Broad-spectrum antibiotics should be administered for 48 to 72 hours. Transcolonic gunshots to the spine are treated with antibiotics for 7 to 14 days. Steroid use does not improve neurologic outcome, and use of steroids is associated with an increased rate of complications. Evidence of acute lead intoxication, an intracanal copper bullet, or new-onset neurologic deficit are potential indications for surgical decompression and bullet removal. Literature does not support bullet removal for intracanal cervical and thoracic gunshots but does support intracanal bullet removal for the T12 to L5 levels.

Key Points

1. Computed tomography (CT) is an integral part of the initial assessment of thoracic and lumbar spine fractures.

2. Comprehensive assessment of a thoracic or lumbar fracture includes a description of the injury mechanism, neurologic status, and integrity of the posterior ligamentous complex (PLC).

3. Abdominal visceral injuries are frequently associated with a flexion-distraction spinal injury mechanism.

Websites

Decision making in thoracolumbar fractures: http://www.neurologyindia.com/text.asp?2005/53/4/534/22626 Orthopaedic Trauma Association Spine Lectures: http://www.ota.org/res_slide/Spine_INDEX.ppt

Surgical treatment of thoracolumbar spine fractures: http://www.coluna.com.br/revistacoluna/volume5/vol_5_%5B2%5Dpg_84-89.pdf Thoracic spine fractures and dislocations: http://emedicine.medscape.com/article/1267029-overview

Thoracolumbar injury classification and severity scale (TLICSS): http://www.orthopaedia.com/display/Main/Thoracolumbar+Injury+ Classification+and+Severity+Scale ■+ %28TLICSS%29

BiBLiOGRAPHY

1. Bono CM, Heary RF. Gunshot wounds to the spine. Spine J 2004;4:230-40.

2. Cammisa FP, Eismont FJ, Green BA. Dural lacerations occurring with burst fractures and associated laminar fractures. J Bone Joint Surg 1989;71A:1044.

3. Denis F. The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 1983;8:817-31.

4. Kim DH, Ludwig SC, Vaccaro AR, et al, editors. Atlas of Spine Trauma: Adult and Pediatric. Philadelphia: Saunders; 2008.

5. Magerl F, Aebi M, Gertzbein SD, et al. A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 1994;3:184-201.

6. McAfee PC, Yuan HA, Frederickson BE, et al. The value of computed tomography in thoracolumbar fractures. J Bone Joint Surg 1983;65A:461-73.

7. Mirza SK, Mirza AJ, Chapman JR, et al. Classifications of thoracic and lumbar fractures: Rationale and supporting data. J Am Acad Orthop Surg 2002;10:364-77.

8. Oner FC, vanGils APG, Faber JAJ, et al. Some complications of common treatment schemes of thoracolumbar spine fractures can be predicted with magnetic resonance imaging. Spine 2002;27:629-36.

9. Parker JW, Lane jR, Karaikovic EE, et al. Successful short-segment instrumentation and fusion for thoracolumbar spine fractures. Spine 2000;25:1157-70.

10. Reitman CR, editor. Management of thoracolumbar fractures. Monograph Series, American Academy of Orthopaedic Surgeons, Rosemont, IL; 2004.

11. Vaccaro AR, Baron EM, Sanfilippo J, et al. Reliability of a novel classification system for thoracolumbar injuries: The Thoracolumbar Injury Severity Score. Spine 2006;31:S62-S69.

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