Vertebral Fracture

Approximately 11,000 new spinal cord injuries occur each year, and approximately 250,000 people in the United States have a spinal cord injury. Approximately half the injuries occur in the thoracic, lumbar, and sacral areas; the other half occur in the cervical spine. The average age at injury is 32 years, and 55% of those injured are aged 16-30 years. Approximately 80% of patients in the US national database are male.[3, 4]

In a retrospective analysis of patients 55 years or older who had traumatic fracture to the lumbar spine, an independent predictor of mortality was age 70 years or older, whereas instrumented surgery and vertebroplasty or kyphoplasty were associated with decreased odds of death.[5]

Vehicular accidents account for approximately one third of reported cases, and approximately 25% of cases are due to violence. Other injuries are typically the result of falls or recreational sporting activities. The incidence of injuries due to violence has been increasing, while the incidence of injuries due to vehicular accidents has been declining.

The cost of a spinal cord injury that causes paraplegia is approximately $200,000 for the first year and $21,000 annually thereafter. The average lifetime cost of treating a patient with paraplegia is $730,000 for those injured at age 25 years and approximately $500,000 for those injured at age 50 years. The life expectancy for individuals with spinal cord injuries is shortened by 15-20 years. The major causes of death are pneumonia, pulmonary embolism, and sepsis.

Fractures of the thoracolumbar spine can be classified into 4 groups based on the mechanism of injury: flexion-compression, axial-compression, flexion-distraction, rotational fracture-dislocation. The mechanism of injury is used interchangeably with the name of the fracture. These major fractures are presented below in escalating order of severity.

Flexion-compression mechanism (wedge or compression fracture)

The flexion-compression mechanism usually results in an anterior wedge compression fracture. As the name implies, the anterior column is compressed, with varying degrees of middle and posterior column insult. (See the image below.)

Ferguson and Allen developed a classification system that characterizes 3 distinct patterns of injury, as follows[6] :

• The first pattern involves anterior column failure while the middle and posterior columns remain intact. Imaging studies demonstrate wedging of the anterior component of the vertebral bodies. Loss of anterior vertebral body height is usually less than 50%. This is a stable fracture.

• The second pattern involves both anterior column failure and posterior column ligamentous failure. Imaging studies demonstrate anterior wedging and may indicate increased interspinous distance. Anterior wedging can produce a loss of vertebral body height greater than 50%. This has an increased possibility of being an unstable injury.

• The third pattern involves failure of all 3 columns. Imaging studies demonstrate not only anterior wedging, but also varying degrees of posterior vertebral body disruption. This is an unstable fracture. Additionally, the possibility exists for cord, nerve root, or vascular injury from free-floating fracture fragments dislodged in the spinal canal.

Axial-compression mechanism

The axial-compression mechanism results in an injury called a burst fracture, and the pattern involves failure of both the anterior and middle columns. Both columns are compressed, and the result is loss of height of the vertebral body. Five subtypes are described, and each is dependent on concomitant (namely rotation) extension and flexion: (1) fracture of both endplates, (2) fracture of the superior endplate (most common), (3) fracture of the inferior endplate, (4) burst rotation fracture, and (5) burst lateral flexion fracture.[7]

McAfee classified burst fractures based on the constitution of the posterior column (stable or unstable).[8] In stable burst fractures, the posterior column is intact; in unstable burst fractures, the posterior column has sustained significant insult. Imaging studies of both stable and unstable burst fractures demonstrate loss of vertebral body height. Additionally, unstable fractures may have posterior element displacement and/or vertebral body or facet dislocation or subluxation. As with a severe wedge fracture, the possibility exists for a cord, nerve root, or vascular injury from posterior displacement of fracture fragments into the canal. Denis showed that the frequency rate of neurologic sequelae could be as high as 50%.[9]  Recommendations call for detailed imaging studies to identify the possibility of canal impingement, which requires decompressive surgery.

Flexion-distraction mechanism

The flexion-distraction mechanism results in an injury called a Chance (or seatbelt) fracture. This pattern involves failure of the posterior column with injury to ligamentous components, bony components, or both. The pathophysiology of this injury pattern is dependent on the axis of flexion. Several subtypes exist, and each is dependent on the axis of flexion and on the number and degree of column failure.

The classic Chance fracture has its axis of flexion anterior to the anterior longitudinal ligament; this results in a horizontal fracture through the posterior and middle column bony elements along with disruption of the supraspinous ligament. This is considered a stable fracture. Imaging studies show an increase in the interspinous distance and possible horizontal fracture lines through the pedicles, transverse processes, and pars interarticularis.

The flexion-distraction subtype has its axis of flexion posterior to the anterior longitudinal ligament. In addition to the previously mentioned radiographic findings, this type of injury also has an anterior wedge fracture. Because all 3 columns are involved, this is considered an unstable injury.

If the pars interarticularis is disrupted in either type of fracture, then the instability of the injury is increased, which may be radiographically demonstrated by significant subluxation. Neurologic sequelae, if they occur, appear to be related to the degree of subluxation.

Rotational fracture-dislocation mechanism

The precise mechanism of rotational fracture-dislocation is a combination of lateral flexion and rotation with or without a component of posterior-anteriorly directed force. The resultant injury pattern is failure of both the posterior and middle columns with varying degrees of anterior column insult. The rotational force is responsible for disruption of the posterior ligaments and articular facet. With sufficient rotational force, the upper vertebral body rotates and carries the superior portion of the lower vertebral body along with it. This causes the radiographic "slice" appearance sometimes seen with these types of injuries.

Denis subtyped fracture-dislocations into flexion-rotation, flexion-distraction, and shear injuries.[9] The flexion-rotation injury pattern results in failure of both the middle and posterior columns along with compression of the anterior column. Imaging studies may demonstrate vertebral body subluxation or dislocation, increased interspinous distance, and an anterior wedge fracture.

The flexion-distraction injury pattern represents failure of both the posterior and middle columns. The pars interarticularis is also disrupted. Imaging studies demonstrate an increased interspinous distance and fracture line(s) through the pedicles and transverse processes, with extension into the pars interarticularis and subsequent subluxation.

The shear (sagittal slice) injury pattern results in a 3-column failure. The combined rotational and posterior-to-anterior force vectors result in vertebral body rotation and annexation of the superior portion of the adjacent and more caudal vertebral body. Imaging studies demonstrate both the nature of the fracture and dislocation.

Each of these fractures is considered unstable. Neurologic sequelae are common.

Minor Fractures

Minor fractures include fractures of the transverse processes of the vertebrae, spinous processes, and pars interarticularis. Minor fractures do not usually result in associated neurologic compromise and are considered mechanically stable. However, because of the large forces required to cause these fractures, associated abdominal injuries may occur. In this context, the index of suspicion for associated injuries should increase and the physician should examine the patient for associated injuries.

Fractures Secondary to Osteoporosis

Osteoporosis causes fractures of the vertebrae and fractures of other bones such as the proximal humerus, distal forearm, proximal femur (hip), and pelvis (see Osteoporosis). Women are at greatest risk. The prevalence rate for these fractures increases steadily with age, ranging from 20% for 50-year-old women to 65% for older women. Most vertebral fractures are not associated with severe trauma. Many patients remain undiagnosed and present with symptoms such as back pain and increased kyphosis. The presence of a significant vertebral fracture is associated with increased mortality. Patients with these fractures have a relative risk of death that is 9 times greater than healthy counterparts. Approximately 20% of women with vertebral fractures have another fracture of a different bone within a year.[10]

Efforts are currently underway to reliably predict who is at risk for these fractures. Bone densitometry is used to assess relative bone strength and fracture risk. Risk factors for osteoporosis fractures include postmenopausal age, white race, and low bone density prior to menopause. Predicting which patients are at risk using risk factor analysis or bone imaging allows for the administration of specific treatments that promote bone deposition or delay resorption. Prevention of fractures is critical and should include exogenous calcium and an appropriate exercise regimen. Many hormonal therapies are also available, including raloxifene and calcitonin.

The American College of Physicians developed a guideline for the pharmacologic treatment of low bone density or osteoporosis to prevent fractures.[11]

Pathologic Fractures

Pathologic fractures are the result of metastatic disease of primary cancers affecting the lung, prostate, and breast. Kaposi sarcoma can also result in vertebral body fractures. Occasionally, cancer affects the spine itself or is the result of meningeal neoplasia. Pathologic fractures tend to affect the vertebral body at both the thoracic and lumbar levels. They cause kyphotic deformity and may result in compression of the cord or cauda equina. If the patient has neurologic deficits, consider emergent radiotherapy, steroid use, and surgical decompression and stabilization. (See the image below.)

Fractures Secondary to Infection

Pott disease (tuberculosis spondylitis) results from the hematogenous spread of microbacteria to the spine [see Pott Disease (Tuberculous Spondylitis)]. Other bacteria can be spread to the spine and cause osteomyelitis. As bacteria proliferate, vertebral damage occurs and primarily affects the vertebral bodies. As in the case of pathologic fractures, associated fractures and an increase in kyphotic deformity may be present. Treatment includes antibiotics. The presence of a neurologic deficit may prompt instrumentation and stabilization of the spine.

Patients With Special Considerations

Elderly patients usually have significant osteoporotic disease and degenerative bone disease. These patients may experience a significant fracture even from a relatively minor, low-energy mechanism of injury. Compression fractures in both the thoracic and lumbar regions are common. These patients also may have pathologic fractures. Central cord syndrome is common for patients who develop neurologic deficits. For elderly patients with stable fractures, early mobilization is important to decrease morbidity and mortality.

Special consideration should be given to pediatric patients with significant trauma to the thoracic or lumbar spine. Because the skeleton is immature and the ligaments are elastic, significant force must be generated to cause a fracture, especially those associated with neurologic deficits. One entity that occurs in pediatric patients is spinal cord injury without radiographic abnormality. If injury and neurologic deficits are strongly considered, perform imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) scans. If the mechanism or circumstances are not consistent with the injury, consider abuse or neglect. Pediatric patients should be examined for additional injuries and bruises.

Patients in altered mental states pose a diagnostic challenge. In the absence of a reliable history and review of systems, findings from the physical examination and radiographic studies can help the physician assess vertebral injuries. In altered or intubated patients with other significant fractures such as pelvic fractures, multiple rib fractures, or scapular fractures, the physician should have a heightened index of suspicion for vertebral fractures. Once these patients have been stabilized, abdominal and chest radiographs may be supplemented with lateral views to reduce the likelihood of a missed vertebral fracture.

Patient history

Details of the injury and mechanism of trauma are helpful in understanding the forces involved and the possible injury. Back pain in the setting of a major accident or a fall from a significant height (>10-15 ft) may increase the index of suspicion. The threshold for obtaining radiographic studies under these circumstances is lowered, and attention to spinal precautions and logrolling is increased. The concern is to not have iatrogenically induced deterioration of neurologic function or worsening of symptoms.

A major accident may involve significant vehicular damage, a head-on collision at high speed, vehicular rollover, or death at the scene. Accidents in which extrication, damage to the steering wheel or windshield, or passenger space intrusion occurred may produce spine injuries. Vehicular accidents involving motorcycles, bicycles, or pedestrians have a higher propensity for spine injuries. Questions about seatbelt use and airbag deployment are helpful in developing a high index of suspicion for vertebral injuries.

Symptoms include pain or the development of neural deficits such as weakness, numbness, and tingling. Even transient symptoms should be investigated. The morbidity of a spinal cord injury is so significant that even minor symptoms should be investigated.

Physical examination

Patients with vertebral fractures secondary to trauma should be evaluated and treated in a systematic fashion as outlined by advanced trauma life-support protocols. At first, attention should be directed toward the patient's airway, breathing, and circulation (ABC). Clinicians should adhere to cervical spine precautions. The patient can be logrolled off the spinal cord while radiographs are performed.

A neurologic examination should be performed as part of the expanded primary survey or secondary survey. The neurologic examination should include the cranial nerves, motor and sensory components, coordination, and reflexes. The physician should examine the pelvic areas, perineal areas, and extremities. A rectal examination is indicated, especially if the patient has weakness in the extremities. An injury to the thoracic or lumbosacral cord would likely result in neural deficits at the trunk, genital area, and lower extremities. Specific syndromes, such as Brown-Séquard syndrome and anterior cord syndrome, may affect a major part of the spinal cord.

Associated injuries

Patients with vertebral fractures typically experience significant force as the cause of injury. As such, they are likely to have associated injuries. Almost any organ can be affected, and the secondary survey should address these issues.

An altered patient may have an intercranial injury. Chest deformity, decreased breath sounds, low oximetry readings, or poor oxygen saturation are commonly associated with pulmonary injury. Consider cardiac injury if the patient has muffled heart tones, rhythm disturbances, or hemodynamic instability. Blunt or penetrating abdominal injury may be associated with spinal fractures; in these situations, conducting a neurologic examination and instituting spinal precautions is important until a spinal cord injury has been excluded. Orthopedic injuries require a significant force to fracture the bone and thus may be associated with vertebral fractures.

A correlation exists between fracture of the transverse process of L1 and same-side renal injury. Patients with calcareous injuries have approximately a 10% chance of associated lumbar vertebral injury. Patients involved in a motor vehicle accident while wearing a lap belt who sustain lumbar fractures are at significant risk for concomitant intra-abdominal injuries (eg, diaphragmatic, hollow viscus, or solid-organ injuries).

Hemodynamic instability

In the setting of a spinal cord injury with a neurologic deficit, close attention should be paid to the hemodynamic status of the patient. In the case of neurogenic shock, hypotension is associated with relative bradycardia as a result of autonomic hyporeflexia. The thoracic sympathetic chain is disrupted, which removes sympathetic tone and leaves unopposed vagal tone. This should be distinguished from hemorrhagic shock, in which a patient is tachycardic, hypotensive, and similarly unresponsive and flaccid. Thus, attention to the heart rate and a mechanism for exsanguination may help differentiate between these forms of shock.

Patients who are on beta blockers may remain bradycardic despite being in hemorrhagic shock. A bedside ultrasound evaluation is a noninvasive screen for free fluid in the peritoneum. The more invasive peritoneal tap and lavage is the classic method of assessment for free fluid. Both types of shock require aggressive fluid and hemodynamic resuscitation.

Spinal shock refers to the temporary loss of spinal reflex activity that occurs below a total or near-total spinal cord injury. It initially results in hyporeflexia and flaccid paralysis. With time, the descending inhibitory influence is removed and hyperreflexive arches, even spasticity, may occur. For patients with spinal shock, pressures may be used after obtaining the proper fluid balance.

Patients with vertebral fractures who are neurologically intact should be assessed for the need for emergent decompressive surgery. Once the patient is hemodynamically stable and life-threatening injuries have been controlled, attention should be directed to neurologic injuries. The second consideration is obtaining a mechanically stable weight-bearing construct that allows for mechanical stability. This facilitates future ambulation and rehabilitation.

Patients with incomplete neurologic injuries need to be assessed for emergent decompressive surgery. For these patients, surgery may help maximize salvage of neurologic function. The surgeon can combine decompressive and stabilization procedures of the spine.

A study by Baldwin et al assessed conservative treatment of thoracolumbar spinal fractures.[12] Given the shortage of neurosurgeons at many trauma centers in the United States, Baldwin et al designed a treatment protocol that used radiologic criteria to screen for potentially stable fractures and to guide treatment without spinal consultation. Using both prospective and retrospective evaluation, the study determined that use of a treatment protocol for stable thoracolumbar fractures appeared safe and could help conserve resources.

Surgery for patients with complete neurologic deficit and paraplegia for more than 2-3 days is controversial. Decompressive procedures have little merit. Spinal stabilization is helpful in achieving mechanical stability and allows for more effective rehabilitation.

Basic vertebral anatomy

The vertebral column has 2 major roles: (1) a structural, weight-bearing role as the centerpiece of the axial skeleton and (2) a role as the conduit for the spinal cord. The vertebral column has 31 vertebrae. The typical vertebral body consists of a ventral segment, the body, and a dorsal part, the vertebral arch. The vertebral arch consists of a pair of pedicles and laminae and encloses the vertebral foramen. The intervertebral disks form the fibrocartilaginous articulation of the vertebral bodies. The vertebral bodies are stabilized anteriorly by the anterior longitudinal ligament and posteriorly by the posterior longitudinal ligament. The spinal canal is formed by the longitudinal apposition of the vertebral bodies, arches, disks, and ligaments. The spinal cord, meninges, and nerve roots course in the spinal canal.

Thoracic region

The thoracic region of the spine has a relatively high stability because of the stabilizing effects of the ribs and the rib cage. This region extends from the first thoracic vertebra (T1) down to the level of 10th thoracic vertebra (T10). Additional stabilizing effects are provided by the almost-vertical orientation of the articulating processes and the shinglelike oblique arrangement of the spinal processes. A significant force is required to cause a fracture or dislocation in this region. The low thoracic region has false ribs at levels T11 and T12; thus, this region of the spine is less stable. This region can be considered the transition zone between the thoracic and lumbar regions because it resembles the lumbar region in stability and mechanisms of injury.

Lumbar and low thoracic regions

The lumbar and low thoracic vertebrae are larger and wider, which is an adaptation required for their weight-bearing role as supports for the upper body and axial skeleton. In contrast to the mid and upper thoracic regions, the lumbar and low thoracic areas lack the stabilizing effect of the rib cage. The spinous processes are more horizontal, which provides increased mobility but less mechanical stability. The lumbar and low thoracic areas have greater mobility, which allows for flexion, extension, and rotation of the upper skeleton in relation to the pelvis and lower extremities.

As a result of increased mobility, the low thoracic and lumbar regions are more susceptible to injury. The transition area between the low-mobility thoracic region (T1 through T10) and the highly mobile lumbar area (approximately T11 through L2) is susceptible to injury. In adults, the spinal cord ends at the lumbosacral enlargement and conus medullaris at approximately the vertebral level of L1. Consequently, injuries to the low thoracic spine and L1 can result in significant paralysis and paraplegia of the lower body because they injure the lumbosacral enlargement of the spinal cord. In contrast, the mid and low lumbar regions are more forgiving because the individual nerve roots of the cauda equina course in this region and they are smaller, more flexible, and more resistant to injury as compared to the lumbosacral enlargement.

Three-column model of the spine

Denis proposed the 3-column model of the spine, which described both the functional units that contribute to the stability of the spine and the destabilizing effect of injuries to the various columns.[9] Denis defines the anterior column as containing the anterior longitudinal ligament, the anterior half of the vertebral body, and the related portion of the intervertebral disk and its annulus fibrosus. The middle column contains the posterior longitudinal ligament, the posterior half of the vertebral body, and the intervertebral disk and its annulus. The posterior column contains the bony elements of the posterior neural arch and the ligamental elements, which include the ligamentum flavum, the interspinous ligaments, and the supraspinous ligaments. The joint capsule of the intervertebral articulations is also part of the posterior column. Disruption of 2 or more columns results in an unstable configuration.

Laboratory studies are not useful in the diagnostic workup of patients with vertebral fractures, although they are important ancillary studies for evaluating possible comorbid conditions.

Patients with vertebral or pelvic fractures resulting from a major trauma require serial hemoglobin determinations as an indicator of hemodynamic stability.

Other laboratory studies aid the evaluation of associated organ damage. A urinalysis or urine dip for blood can help rule out associated kidney injury. An elevated amylase or lipase level may suggest pancreatic injury. Elevated cardiac markers in the setting of chest trauma may indicate a cardiac contusion. Elevated urine myoglobin or serum creatine kinase level in the context of a crush injury may indicate evolving rhabdomyolysis. A pregnancy test should be obtained in females of childbearing age.

In patients with metastatic disease to the bone and resultant pathologic fractures, a serum calcium determination is necessary. These patients may have hypercalcemia that requires medical attention.

Routine laboratory analysis is part of the preoperative workup. The evaluation should include a complete blood cell count, serum chemistries, coagulation profile, and urinalysis. Results of these studies have a bearing on total patient care rather than specific issues related to the fracture.

Upon initial presentation to the emergency department, plain radiographs should be obtained if a vertebral fracture is suggested based on the results of the clinical examination. Plain radiographs are helpful in screening for fractures, but hairline fractures or nondisplaced fractures may be difficult to detect.

CT scan imaging can readily detect bony fractures and help with the assessment of the extent of fractures. CT scans are very sensitive and can identify even subtle fractures.[1] A CT myelogram can be used to determine the degree of impingement of the bony fragments on the thecal scan when MRI imaging is not available or is contraindicated.

MRI is usually the study of choice to detect the extent of damage to the spinal cord. MRI is the most sensitive tool for detecting lesions of both neural tissue and bone.[13]  The American College of Radiology recommends MRI for patients with suspected spinal cord injury, cord compression due to disc protrusion or hematoma, or suspected ligamentous instability.[1]

In a study to determine thoracolumbar spine injury in 13 US trauma centers, the majority underwent computed tomography (93.3%), 6.3% only plain films, and 0.2% magnetic resonance imaging exclusively. Thoracolumbar spine injury was identified in 499 patients (16.3%). Positive clinical examination (pain, midline tenderness, deformity, neurologic deficit) resulted in a sensitivity of 78.4% and a specificity of 72.9%. The addition of age of 60 years or older and high-risk mechanism (fall, crush, motor vehicle crash with ejection/rollover, unenclosed vehicle crash, auto vs. pedestrian) increased sensitivity to 98.9% with specificity of 29.0% for clinically significant injuries and 100% sensitivity and 27.3% specificity for injuries requiring surgery.[14]

Bone densitometry can be performed in an attempt to predict the risk of fracture from osteoporosis. Results from an imaging study such as plain radiography or spiral CT scan can be compared to a known standard. Patients with significant loss of bone density can be given treatment to enhance bone deposition.

Prehospital care

Paramedics and first responders ascribe to the basic tenet of "do no harm." Their routine protocol is to use spinal immobilization for patients with major traumatic injuries, patients whose mechanism of injury is not clear, and patients who may have experienced some trauma. Of course, the initial focus is on cervical spine injuries, and they routinely apply a cervical spine immobilization device, typically a rigid plastic cervical collar. They use a logroll technique when transferring the patient onto a long spine board or rescue board, which avoids unnecessary movement. Once on a spine board, the patient is secured and prepared for transport. Even patients with no spinal tenderness or neurologic deficits are transported in this fashion. The goal of routine spinal immobilization protocols is to avoid injuries during transport and during the prehospital phase.

Once in the hospital, remove the patient from the board as soon as practical. Prolonged use may be uncomfortable and even counterproductive, because uncomfortable patients may start moving on the board. Some patients develop skin breakdown and decubitus ulcers, even after 1 hour of use. Controlled transfer, use of a sliding board or scoop system, and the logroll technique can prevent further injury. Adequate personnel are needed to facilitate these transfers.

Emergency department management

Focus the initial assessment and stabilization of patients with spine injuries on the ABCs and patient immobilization. As part of the initial assessment and stabilization, the airway may need to be secured using rapid-sequence intubation and spinal stabilization. Once the ABCs algorithm is satisfied, focus attention on the secondary survey. Quite often, these patients are victims of multiple traumas. Associated injuries, such as brain, thoracic, or abdominal injuries, take precedence. The neurologic examination helps determine the presence of deficits. In the presence of neurologic deficits, hypotension and bradycardia may indicate neurogenic shock.

The treatment goal for patients in neurogenic shock is to maintain hemodynamic stability. Maintain the systolic blood pressure at a value of at least 90 mm Hg with a heart rate of 60-100 beats per minute. Initial treatment of hypotension is fluid resuscitation; typical adults may require up to 2 liters of crystalloids. Bradycardia may be titrated by the use of atropine. Attempt to maintain urine output at a minimum of 30 mL/hr. If all of the above parameters are difficult to maintain, consider support with inotropic agents. These patients are also at risk for hypothermia and should be warmed to maintain a core temperature of at least 96°F. Place a Foley catheter to help with voiding. A nasogastric tube can help with ileus, which is common in the setting of spinal injury. Priapism is not usually treated.

Paramedics and rescue personnel often transport patients on a spinal board with complete spinal immobilization. The objective is to minimize the possibility of injury during transport. Traditionally, patients have been kept on the spinal board until all radiographic studies were completed and no fractures were identified. A more practical approach is to logroll patients off the board, even prior to obtaining radiographs. A cervical collar can be kept in place until the cervical spine is cleared. The objective is to provide maximal patient comfort while minimizing iatrogenic injury. Early clearance from the spinal board can prevent formation of pressure sores and necrosis. Ensure that patients are turned every 1-2 hours to prevent decubitus ulcer formation. Administer pain medication to maintain patient comfort.

For patients with blunt trauma injuries and neurologic deficits, consider the administration of high-dose intravenous steroids to help minimize deficits. Begin steroid therapy within 8 hours of the injury. The initial dose of methylprednisolone is 30 mg/kg administered over 15 minutes. Start an infusion for the maintenance dose of 5.4 mg/kg/hr at the beginning of the first hour and continue it through the 23rd hour. Studies have shown that steroid use may result in complications and inconsistent results.[15, 16, 17, 18]

Nonsurgical management of fractures

Fractures may be managed operatively or nonoperatively depending on the extent of spinal cord injury and the overall health of the patient. Minor fractures or those with column stability are managed nonoperatively. Major fractures or those with significant instability can be managed operatively. Operative management is used for stabilization of the spinal column and prevention of spinal deformity, although major factors in nonsurgical candidates can be treated conservatively with nonoperative treatment.

Nonoperative management of unstable spinal fractures involves the use of a spinal orthotic vest or brace. The objective of the brace is to prevent rotational movement and bending. Give consideration to the stabilization of patients with spinal cord injuries and paraplegia. These patients need to be stabilized sufficiently so that their upper body and axial skeleton are appropriately supported, which allows for effective rehabilitation. Stabilization allows patients to use their upper body strength to help with mobility and rehabilitation.

Spinal orthoses are somewhat uncomfortable and only partially effective in providing full stabilization of the thoracic and lumbar spine. The thoracolumbar junction is especially difficult to immobilize externally. As with cervical collar immobilization of the neck, the patient can exhibit an almost complete range of motion with minimal effort. External braces and orthoses primarily serve as a reminder to the patient to minimize movement. A more effective means of immobilization is the body cast, although the body cast is very uncomfortable and may not be well tolerated.

High-dose steroids

Results from the National Acute Spinal Cord Injury Study (NASCIS) demonstrated the benefit of high-dose steroid administration after blunt spinal cord trauma.[16, 19] Methylprednisolone administration resulted in improved motor and sensory function in subjects with moderate or severe spinal cord injuries. The conclusion of the study was that high-dose methylprednisolone administered within 8 hours of injury resulted in improved motor and sensory function. In the first hour of the protocol, a bolus of 30 mg/kg was administered. For the following 23 hours, patients were given a steroid infusion of 5.4 mg/kg/hr. Because researchers noted that patients improved significantly, the clinical trial was halted with the assumption that high-dose steroids were a viable treatment for acute spinal cord injury. The treatment was not targeted at patients with penetrating trauma injuries.

Later studies showed inconsistent results. Some studies did not demonstrate an improvement of the neurologic deficit. Other studies showed long-term detrimental effects, such as increased rates of infection, including pneumonia.

Positioning of the patient and anesthesia considerations

Depending on the surgical approach, the patient must be properly positioned. For a posterior approach, place the patient in the prone position with either horizontal or flexed positioning at the hips. For a lateral approach, the surgeon can use either the prone position or a modified lateral decubitus position. For the ventral approach, position the patient supine. Ensure that the anesthesiologist has proper intravenous access and access to the extremities and chest for intraoperative monitoring. Exercise the usual precautions of positioning and avoidance of pressure on peripheral nerves, eyes, and other organs. Surgery is usually performed with the patient under general anesthesia with endotracheal intubation. Prophylactic antibiotics are routine. To obtain maximum pain control, the incision is infiltrated with a local anesthetic. During surgery, implement prophylaxis for deep venous thrombosis with use of pneumatic sequential compression devices or thromboembolic disease (TED) stockings.

Operative approaches

The goals of operative treatment are to decompress the spinal cord canal and to stabilize the disrupted vertebral column. Three basic approaches are used for surgical management of the thoracolumbar spine: (1) the posterior approach, (2) the posterolateral approach, and (3) the anterior approach. Selection of the best approach is guided by the anatomy of the fracture and the location of spinal canal encroachment. Also consider the need for stabilization procedures.

The posterior approach with a midline incision and a laminectomy allows for access to the posterior elements, although it does not permit access to the vertebral bodies and, as a result, is not commonly used. Spinal cord compression as a result of isolated fractures of the posterior elements is not very common. Spinal canal compromise is more frequent when the vertebral bodies and anterior elements are involved. The posterior approach is useful for stabilization procedures that involve fixation of the posterior bony elements. The posterior approach is used when early mobilization is considered and decompression of the spinal canal is not a major consideration.

The posterolateral technique improves access to the vertebral bodies, although access is still limited. Decompression of ventral impingement of the canal is technically difficult using this approach. It is useful when only a limited exposure of the ventral elements is required. It may be combined with a posterior stabilization procedure when limited ventral exposure is needed. The approach to the high thoracic segments is technically difficult. This technique is often used for high thoracic fractures such as T1 through T4.

The anterior approach allows access to the vertebral bodies at multiple levels. Transthoracic exposure is required in order to access the vertebral bodies down to L2. Lower fractures require a transabdominal-retroperitoneal exposure. It is most useful for decompression of injuries and spinal canal compromise caused by vertebral body fractures. Examples of significant vertebral body fractures include a burst fracture, sagittal slice fracture, and severe compression fractures. Sometimes, a modified combined approach is used to maximize exposure and access. When an anterior approach is used, the vertebral bodies are often resected and replaced with autologous bone or bone from the bone bank. This technique, unlike the posterior stabilization procedures, does not result in early stability.

Surgical exposure

Proper exposure of the affected area is necessary. Often, going several segments above and below the affected area is necessary in order to ensure optimal exposure and proper placement of stabilizing hardware. The skin and soft tissue incision may be 10 cm or more in depth, and the incision requires retractors for optimal exposure. Meticulous attention to hemostasis is required because even minimal bleeding may cause the operative area to eventually fill with blood. If at all possible, keep the thecal sac intact. Evacuate epidural or subdural hematomas.

Categories of procedures for spine stabilization

Posterior lumbar interspinous fusion is the least-invasive method and involves the use of screws to obtain stability and promote fusion. Most patients have good results with this technique. It can be used effectively for isolated or relatively stable fractures.[20]

Posterior rods require extensive exposure and are effective in stabilizing multiple fractures or unstable fractures. The use of rods prevents further deformity and deterioration. The rods are attached with pedicle screws, stainless steel wires, clips, and clamps to achieve a stable construct. Also, in the case of spinal tuberculosis, use of posterior stabilization using long rods prevents further deterioration and deformity.[21, 22, 23]

Compression fractures with an intact posterior cortical wall can be treated by means of a kyphoplasty, which involves transpedicular placement of a balloon through a bone biopsy needle and cannula into the compressed vertebral body under fluoroscopic guidance. The balloon is inflated under controlled pressure, resulting in expansion of the vertebral body and creation of a cavity. The cavity is then filled with bone cement. This results in elevation of the endplate and stabilization of the fracture fragments, with a consequent reduction of pain.[24, 25, 26]

The Z-plate anterior thoracolumbar plating system has been used for the treatment of burst fractures. Surgery is performed for neurologic deficits, deformity, progressive kyphosis, and late pain. Ghanayem and Zdeblick reported good success with this form of anterior arthrodesis.

Postoperative care of the surgical incision

The incision is usually closed in a layered fashion, and the skin is either stapled or sutured. A dressing is applied and taped in place. Some surgeons keep the dressing in place postoperatively for 24-48 hours. Other surgeons elect to inspect the incision the next day and subsequently place a fresh dressing. Postoperative antibiotics may be given for up to a total of 3 doses. If a significant amount of stabilizing hardware was implanted, continuation of antibiotics is appropriate.

Prevention of complications

Patients are susceptible to postoperative cardiac complications such as myocardial infarction. Place patients with risk factors in an intensive care unit or monitored setting. Pulmonary complications, which cause pain and decreased tidal volume, can occur as a result of stabilizing procedures. Use incentive spirometry to help patients with deep breathing and early ambulation. The patient's hematocrit value should be monitored, especially for those patients with significant blood loss during surgery. Similarly, monitor renal function and electrolyte values, especially for susceptible patients. Patients are at risk for deep venous thrombosis after any surgery or prolonged immobilization. Precautions include the use of pneumatic compression devices, TED stockings, or subcutaneous heparin injections.

Remove the Foley catheter after 24-48 hours or once the patient is ambulatory. This decreases the risk of urinary tract infections and possible hematogenous spread to the spine and implanted hardware.

The operating surgeon reevaluates the patient within 1-2 weeks of surgery. Of course, if patients experience postoperative complications or complicated surgeries, they are seen within 2-3 days after discharge.

Rehabilitation and physical therapy

Early ambulation is recommended for patients who are neurologically intact or those who have limited neurologic impairment. Pain control is important to facilitate early ambulation. Patients with significant neurologic impairment or those who are paraplegic should also have active recovery and early mobilization. Full stabilization may take up to 2 years. The rate of improvement depends on the ongoing maturation of the fused vertebrae and the conditioning of the muscles. Recommend that patients refrain from smoking because this impairs the healing process.

Rehabilitation facilities

Patients with significant neurologic impairment or those who are paraplegic may need to spend time at a rehabilitation facility until they have been trained to adapt and to cope with their disability. The focus of rehabilitation is on bowel and bladder management and on transfer techniques. Psychological counseling is essential to help patients cope with their injury. Some patients may require antidepressant or antianxiety medications. Proper pain management is also important for successful rehabilitation.

Complications of vertebral fractures may include mechanical complications from the fracture itself, neurologic deficits, and resultant comorbid conditions. Surgical stabilization procedures also have associated complications.

A study by Dimar et al identified factors predictive of complications after surgery to stabilize thoracolumbar spinal injuries.[27] The study determined that severity of neurologic injury, quantity of associated morbidities, and high-dose steroid use independently increase the risk for major complications after stabilization.

Mechanical complications

Vertebral fractures of the thoracic and lumbar spine that are somewhat mechanically unstable and have not been stabilized with instrumentation may develop progressive deformity despite the use of an orthotic brace. Such a deformity may hamper rehabilitation. Unstable fractures may result in further deterioration of a partial neurologic lesion.

Neurologic deficits

In the acute phase, patients with partial spinal cord injuries may experience an increase of the neurologic deficit. The initial flaccid paralysis may turn into spasticity.

Resultant comorbid conditions

A major complication of thoracic or lumbar spinal cord injury and the resultant paraplegia is the development of pressure sores. Prevention starts in the emergency department; patients need to be removed from spinal cord immobilization as soon as possible. During hospitalization, decubitus precautions should be implemented; the patient should be turned frequently. Use of egg-crate foam mattresses or air mattresses is also protective. Educating the patient and any caregivers is another important component of prevention.

Pulmonary complications may occur in patients with high thoracic injuries. In the acute phase, associated rib fractures and pulmonary contusions may occur. This predisposes the patient to hypoxemia and other complications. Also, the diaphragm, the major muscle of respiration, is supplied by the phrenic nerve at cervical spine levels C3 through C5; the diaphragm is also supplemented by the intercostal muscles from thoracic segmental levels. This could result in a decrease in the tidal volume of respiration, thus predisposing the patient to atelectasis and pneumonia.

Patients with spinal cord injuries are predisposed to the development of ileus and constipation. They should be treated to prevent impaction and associated complications. In the acute phase, a nasogastric tube may be placed for the first 24-48 hours. Early enteral feeding via a feeding tube at a slow rate may be tolerated. The feeding rate should be advanced slowly until complete nutritional support is provided and is adequately tolerated.

The initial multicenter clinical trials that used methylprednisolone for the treatment of spinal cord injury, the NASCIS II trial, were promising and methylprednisolone quickly turned into the standard of care. Patients showed significant improvement of neurologic function at 6 months after injury, provided they were treated within 8 hours of injury. In some individuals who had spinal cord epidural hematomas with neurologic deficits, significant improvement was observed after high-dose methylprednisolone treatment.

At the molecular level, some benefit appears to be gained with the use of high-dose methylprednisolone. Animal studies show a decrease in the production of deleterious compounds and molecules by the cell, such as the expression of p75 neurotrophin receptor. Likewise, methylprednisolone reduces spinal cord injury in rats by decreasing lipid peroxidation; however, a decrease in production of protective tumor necrosis factor-alpha also occurs.

Bracken performed a meta-analysis of several studies on the topic. He concluded that high-dose methylprednisolone given within 8 hours is a safe and relatively effective therapy in some patients. A meta-analysis by Hurlbert (and other studies) failed to show that high-dose steroids improved patient outcomes. Controversy exists because methylprednisolone is not a completely benign drug and adverse effects can occur. High-dose steroids may have detrimental effects, such as immunosuppression and adrenal suppression. From an evidence-based approach, methylprednisolone should not be recommended for routine use.[16, 17, 19]

Osteoporosis screening to prevent fractures is recommended by the following organizations:

• American Association of Clinical Endocrinologists (AACE)--(guidelines for postmenopausal women) ^[28]  
• US Preventive Services Task Force (USPSTF) ^[29]
• American Academy of Family Physicians (AAFP) ^[30]

AACE guidelines recommend evaluation of all women age 50 years or older for osteoporosis risk. The initial evaluation should include a detailed history, physical exam, and clinical fracture risk assessment with the Fracture Risk Assessment (FRAX) tool or other fracture risk assessment tool.[28]

The USPSTF and AAFP both recommend screening for osteoporosis with bone measurement testing to prevent osteoporotic fractures in women 65 years and older and in postmenopausal women younger than 65 years who are at increased risk of osteoporosis, as determined by a formal clinical risk assessment tool.[29, 30]

 

The American College of Radiology Appropriateness Criteria has noted the following recommendations[1] :

• CT is preferred to radiographs for initial assessment of spine trauma.
• CT angiography and MR angiography are both acceptable in assessment for cervical vascular injury.
• MRI is preferred to CT myelography for assessing neurologic injury in the setting of spine trauma.
• MRI is usually appropriate when there is concern for ligament injury or in screening obtunded patients for cervical spine instability. 

Guidelines for the treatment of lumbar and thoracic spine fractures were developed by the American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) Section on Disorders of the Spine and Peripheral Nerves and the Section on Neurotrauma and Critical Care workgroup. They are summarized below[31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43] :

Nonoperative care

Whether to use an external brace is determined at the discretion of the treating physician. Nonoperative management of neurologically intact patients with thoracic and lumbar burst fractures, either with or without an external brace, produces equivalent improvement in outcomes. Bracing is not associated with increased adverse events.

Surgical decompression

The preferred posterior skin incision is a midline one. The length of the incision should permit complete visualization of the entire hemilamina rostral and caudad to the appropriate interlaminar space or spaces, as well as the entire facet complex.

The lumbodorsal fascia is incised with the electric knife just lateral to the spinous process and supraspinous ligament. Atraumatic dissection of the muscles off the spinous processes, laminae, and transverse processes is accomplished with a periosteal elevator and electric knife. After exposure of the appropriate interlaminar area, a self-retaining retractor is used to retract the musculofascial layers. Posterior element fractures usually are visualized at this time.

If compression of neural structures has been determined preoperatively, adequate bilateral exposure and decompression of ligaments and bone are then performed with a high-speed drill, rongeurs, and Kerrison punches and carried both rostrad and caudad well beyond the area of neurocompressive pathology. All residual ligamentum flavum is gently microdissected from the dura and nerve root sheath and excised with either a 2- or 3-mm thin-footplate Kerrison rongeur.

Once adequate dorsolateral decompression and exposure of the dural sac and involved nerve root have been accomplished, a generous foraminotomy is accomplished with the thin-plate Kerrison rongeur.

Posterior intertransverse fusion

The spine is exposed through a posterior midline incision and subperiosteal muscle dissection. The incision length must be sufficient to enable full exposure of the transverse processes. The dissection is carried out laterally over the facet joint to expose the transverse processes completely at the levels to be fused. All soft tissue is meticulously removed from the grafting area, including the transverse process, the lateral aspect of the superior facet joints, and the pars interarticularis.

The bone graft can be harvested either through the previously made midline incision or through the separately placed lateral incision. The superior and outer margins of the iliac crest are exposed subperiosteally. Multiple corticocancellous strips are harvested.

After adequate bone harvest, the donor bed is copiously irrigated with antibiotic solution and waxed to reduce blood loss. This wound is closed in layers. Decortication of the graft bed usually is performed with a high-speed drill. The harvested bone then is placed onto the recipient bone bed and packed into the facet joints. The wound is copiously irrigated and closed with an absorbable suture.

The intertransverse process region provides ample surface area for graft contact, which results in a high rate of fusion. Exposure of this region requires substantial paraspinal muscle dissection, which can be bloody and time-consuming. This technique does not decrease immediate motion, correct deformity, or maintain spinal alignment and generally is used in conjunction with pedicle screw placement.

Posterior interbody fusion

Lumbar interbody fusion remains a popular method of arthrodesis because it allows access to the anterior weightbearing spinal column through a standard posterior laminectomy. This technique seems most ideally suited for cases of mechanical instability that require concomitant spinal canal or disk space entry for decompression. Patient position and initial spinal exposure are similar to those described for intertransverse process fusion. The dissection need only be carried out to the lateral aspect of the facet joints.

The use of this technique in the paramedial space is known as posterior lateral interbody fusion, whereas a more lateral approach is known as transpedicular interbody fusion. [53, 54]

Anterior corpectomy and fusion

Various approaches to the anterior lumbar and lumbosacral spine have been described. Proper exposure of the anterior lumbar spine requires a detailed knowledge of the neurovascular soft tissue surrounding the anterior spine.

After incision of the abdominal wall musculature, the peritoneal sac is bluntly freed from its attachment to the transversalis fascia until the spine and psoas muscle are identified. The ureter usually remains attached to the posterior peritoneum and is elevated away from the spine during the dissection. It must be identified and protected before any sharp dissection is performed.

Once adequate exposure has been achieved, self-retaining retractors are used. Injury to the great vessels is a common complication of surgery. Therefore, these vessels must be adequately protected during this dissection.

Localization of the vertebral fracture is performed with a cross-table lateral radiograph. Once the correct level has been exposed, the superior and inferior disks are removed by using a long knife, rongeurs, curets, and osteotomes. The vertebral corpectomy is performed by using a high-speed drill, curettes, osteotomes, and rongeurs, with special care taken in approaching the spinal canal.

Once adequate decompression has been achieved, the cartilaginous endplates are removed down to bleeding subchondral bone. Spinal fixation is placed in the adjacent vertebral bodies, and gentle distraction of the corpectomy is achieved with a distractor. [52]

Posterior internal fixation with pedicle screws

Internal fixation as an adjunct to spinal fusion has become increasingly popular. Titanium rods are longitudinally anchored to the spine by hooks or transpedicular screws. Powerful forces can be applied to the spine through these implants to correct deformity.

Implants provide immediate rigid spinal immobilization, which allows early patient mobilization and affords a more optimal environment for bone graft incorporation. Pedicle fixation systems are the most commonly used implant type in the lumbosacral spine. The large size of the lumbar pedicles minimizes the number of instrumented motion segments required to achieve adequate stabilization.[58]

Kyphoplasty

Compression fractures with an intact posterior cortical wall can be treated by means of a kyphoplasty, which involves transpedicular placement of a balloon through a bone biopsy needle and cannula into the compressed vertebral body under fluoroscopic guidance. The balloon is inflated under controlled pressure, resulting in expansion of the vertebral body and creation of a cavity. The cavity is then filled with bone cement. This results in elevation of the endplate and stabilization of the fracture fragments, with a consequent reduction of pain.