Injuries of the subaxial cervical spine (C3-7) are among the most common and potentially most devastating injuries involving the axial skeleton. The cervical spine often is injured in motor vehicle accidents and falls, resulting in bony or soft-tissue injury; however, the presence of multiple traumatic injuries may distract the examiner from the cervical spine. In the evaluation of the polytrauma patient, examining the cervical spine is a high priority and must take precedence.
The cervical spine is important to consider in positioning the head in space. The dominant motion in the lower cervical spine is flexion-extension, but the cervical spine's anatomy permits a fair amount of motion in all planes. In high-speed injuries, the head can act as a significant lever arm on the cervical spine and, depending on the mechanism, can create a wide array of injury patterns.
The lower cervical spine can suffer minor bony or ligamentous injury that nevertheless results in severe neurologic injury. However, the converse is also true: Major bony or ligamentous injury to the lower cervical spine can present with only neck pain. Thus, a thorough and orderly approach to the examination is paramount. Recognizing injury to the lower cervical spine is important because of the association between these injuries and spinal cord and nerve root injury. Little room for malalignment exists in the lower cervical spine, and safe and expeditious realignment is of the utmost priority.
The age distribution of patients presenting with injuries to the lower cervical spine and spinal cord is bimodal. Injuries in persons aged 15-24 years are usually the result of high-energy trauma, such as motor vehicle accidents, accidents resulting from sporting activities, or acts of violence.[1] Injuries in persons older than 55 years usually result from low-energy trauma, such as falls from the standing position. The age-associated cervical spondylosis narrows the spinal canal and predisposes the cervical cord to injury at this level.[2]
In patients presenting to an emergency facility with a history of a high-speed motor vehicle accident, significant head or facial trauma, a neurologic deficit, or neck pain, a cervical spine injury should be assumed to be present until proved otherwise. Whereas assessment of airway, breathing, and hemodynamic stability continues to be the highest priority in caring for the patient with multiple traumatic injuries, central nervous system (CNS) evaluation follows closely behind. The CNS assessment begins in the field; the cervical spine is protected until workup proves that it is not injured.
Operative stabilization of the cervical spine was introduced by Hadra in 1891, when he wired the spinous processes of a child who had a fracture dislocation with progressive neurologic deterioration. This was the first surgical procedure of its kind recorded in the literature.
Further refinement in the application of internal fixation was documented by Rogers in 1942 with a simple wire technique, and by Bohlman with the use of triple-wire stabilization. Rogers reported successful fusions in 37 of 39 patients with 1-12 years of follow-up. Bohlman's technique involved using separate wires for fixation of the adjacent spinous processes and compression of two corticocancellous grafts against the spinous processes. Biomechanically, this was thought to provide better flexural and torsional stiffness than Rogers' simple wiring. Weiland and McAfee reported 100% fusion rates in 60 patients using this means of fixation in the subaxial cervical spine.
Roy-Camille pioneered the use of posterior cervical plates to manage a variety of injuries involving the posterior subaxial spine. Magerl, Anderson, and An proposed variations of screw insertion techniques. Anterior spinal reconstructions evolved from the use of grafts alone (iliac crest, fibula) supported with external immobilization (halo vest), to the use of anterior instrumentation with plates and bicortical screw fixation (Caspar), to unicortical locking plates (Morscher Synthes cervical spine locking plate [CSLP] system).
Skull traction using modified ice tongs was introduced by Crutchfield in 1933. The halo device was pioneered by Nickel and Perry in the late 1950s, primarily to immobilize the cervical spine affected by polio. Its application was extended to trauma cases, providing a better means of immobilization.
The subaxial cervical spine can conveniently be divided into anterior and posterior columns. The anterior column consists of the typical cervical vertebral body sandwiched between supporting disks. The anterior surface is reinforced further by the anterior longitudinal ligament and the posterior body by the posterior longitudinal ligament, both of which run from the axis to the sacrum. Articulations include the disk-vertebral body, uncovertebral joints, and zygapophyseal joints.
The disk is thicker anteriorly, contributing to the normal cervical lordosis, and the uncovertebral joints located in the posterior aspect of the body define the lateral extent of most surgical exposures. The zygapophyseal or facet joints are oriented at 45º to the axial plane, allowing a sliding motion, as the joint capsule is weakest posteriorly. Supporting ligamentum flavum and posterior and interspinous ligaments also strengthen the posterior column.[3] (See the image below.)
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Normal anatomy of the lower cervical spine.
In the neuroanatomy of the cervical spine, the cord is enlarged, with lateral extension of the gray matter consisting of the anterior horn cells. The lateral dimension spans 13-14 mm, and the anterior-posterior extent measures 7 mm. An additional 1 mm is necessary for the cerebrospinal fluid (CSF) anteriorly and posteriorly, as well as 1 mm for the dura. A total of 11 mm is needed for the cervical spinal cord. Exiting at each vertebral level is the spinal nerve root, which is the result of the union of the anterior and posterior nerve roots. (See the image below.)
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Cross-sectional anatomy of the cervical cord.
Interconnections are present between the sympathetic nervous system and the nerve root proper. Because the numbering of the cervical roots commences above the atlas, eight cervical roots exist, with C8 exiting between the seventh cervical vertebra and the first thoracic level.
The vascular anatomy consists of a larger anterior spinal artery located in the central sulcus of the cord and paired posterior spinal arteries located on the dorsum of the cord. It is generally accepted that the anterior two thirds of the cord is supplied by the anterior spinal artery and the posterior one third by the posterior arteries.
Various mechanisms may be responsible for ligamentous and bony failure in the subaxial cervical spine. The importance of the position of the head and neck at the time of impact and the direction of force causing injury cannot be overemphasized. Clinical examination and critical review of the imaging studies help determine the type of failure and, therefore, the reconstruction required.
Conceptually, the cervical spine may be viewed as being composed of two columns. An anterior load-bearing structure consists of all structures anterior to and including the posterior longitudinal ligament. The posterior column includes the pedicles, laminae, facet joints, spinous processes, and the posterior ligament complexes (ligamentum flavum, interspinous ligaments, and supraspinous ligaments). Tension is resisted by the posterior column, which fails under extreme flexion or distraction and which may be associated with concomitant injury to the anterior column.
Allen et al introduced a comprehensive classification system of injuries,[4] which included the following three common mechanisms:
Compression-flexion
Distraction-flexion
Compression-extension
Vertical compression injury results in the burst-type injury with anterior column failure. Less common modes of insult are the distraction-extension and lateral flexion subtypes. These are classified further into stages of progressive injury.[5]
Motor vehicle accidents, falls, and accidents resulting from recreational activities are the leading causes of injuries to the lower cervical spine. Motorcycle accidents account for approximately 20% of motor vehicle accidents leading to spinal cord injuries (SCIs). The incidence of falls leading to injury is higher in older persons (those aged 65 years or older). Spinal injuries have increased among skiers and snowboarders.[6]
Cervical spine injury has been reported in 2-4.6% of patients presenting with blunt trauma. It is the most devastating musculoskeletal injury and occurs most frequently in young patients. SCI occurs in more than 11,000 patients per year, or in 40-50 persons per 1 million population. Injuries to the cervical spine produce neurologic damage in approximately 40% of patients. In approximately 10% of traumatic SCIs, radiographs reveal no obvious evidence of bony abnormality.
The clinical outcome after lower cervical spinal injury generally is related to the level and severity of associated SCI. Incomplete SCIs, as defined by objective motor or sensory preservation below the level of trauma, have the potential for recovery. In general, the sooner the evidence of return, the better the overall prognosis, though recovery may continue for 1 year or longer.
The level of injury also determines the overall functional status of the patient, as follows:
The patient with C3-4 level cord injury must use a sip-and-puff (mouth) or chin/head control for mobilization in a wheelchair
Patients with C5 level injuries, as defined by greater than three fifths strength in the respective muscle group, are able to assist with upper-body dressing, can feed themselves with assistive devices, and can operate a power wheelchair
Some grooming and assistance with bowel and bladder programs are within the realm of capabilities of the quadriplegic patient with C6 level injuries; these patients are able to feed themselves with hand or tenodesis splints and can transfer to and from wheelchairs or toilets with some assistance
Patients with injuries at the C7 level can transfer independently to the bed, car, or toilet; can use manual or power wheelchairs; and can dress independently using assistive devices
Patients with injuries at the C8 level or below should be independent in all transfers and be able to use a manual wheelchair and assist in some homemaking activities
The life expectancy of patients with cervical SCIs has increased with better management of urinary complications. Urinary complications are no longer among the most common causes of death after the first year after injury.
Fracture or dislocation of the cervical spine should be suspected in any patient involved in a high-velocity injury. Successful treatment starts with appropriate transportation of the patient from the scene of the accident to the trauma center. Airway, breathing, and circulation should always be the highest priority. Immobilization of the cervical spine with sandbags or a cervical collar and placement of the patient on a long spine board help prevent secondary injury. Transfers and intubation should be accomplished under strict spine precautions.
An initial history should be taken, and mental status and consciousness level should be assessed. Important points to note are whether the patient was thrown from the vehicle, whether the patient hit his or her head, and whether any indication of paralysis was present at the time of the accident. Voluntary actions, neurologic function, and regions of pain also should be noted.
The patient should be inspected thoroughly for lacerations or abrasions on the scalp, face, neck, or shoulders as clues to the mechanism of injury. The back of the neck should be palpated for any tenderness, stepoff, or hematoma.
A thorough neurologic examination should be performed as soon as possible to detect any evidence of cord damage. It should follow the standards established by the American Spinal Injury Association (ASIA).[7] Motor strength is graded on a scale of 0-5 in all major myotomes.
A systematic sensory examination is performed to detect light touch, pinprick, and proprioception in all key dermatomes of the trunk and extremities. Deep tendon reflexes are recorded. These include the biceps (C5), triceps (C7), and brachioradialis (C6) for the upper extremities, along with the patella (L4) and Achilles (S1) for the lower extremities.
The presence of pathologic reflexes also should be noted. Clonus is a sustained, repetitive, involuntary contraction of a major muscle group, usually seen in the Achilles and recorded as the number of "beats" or contractions sustained. The Hoffman sign is seen in the hands with forced passive flexion of the distal interphalangeal (DIP) joint of the long finger causing a reflex contraction of the flexors of the index finger and thumb. The Babinski sign is seen when the toes exhibit an upward motion as opposed to a downward motion in response to a stroking stimulus on the bottom of the foot.
Particular emphasis should be placed on the examination of the sacral roots and reflexes. These are extremely important for two reasons. First, detection of sacral sparing indicates an incomplete spinal cord injury (SCI). Second, return of the sacral reflexes indicates the passing of spinal shock. Anal sphincter tone and perianal sensation are good tests of sacral root function. The bulbocavernosus reflex and anal wink are good tests of the sacral reflex arc.
Repeating examinations serially is crucial to determine the end of spinal shock, which usually occurs in 24 hours. Serial examinations also help determine whether an incomplete lesion is improving or worsening. This facilitates definition of the best treatment pathway.
Methods of classifying subaxial cervical spine injuries have included the Holdsworth, Allen, and Harris systems, along with the Subaxial Injury Classification (SLIC; first described by Vaccaro et al[8] ) and severity scale and the Cervical Spine Injury Severity Score (CSISS). The American Association of Neurological Surgeons (AANS) has recommended the SLIC and the CSISS for use in categorizing lower cervical spine injuries.[9]
The SLIC assigns points within three categories—morphology, discoligamentous complex (DLC), and neurologic status—to derive a score. With respect to morphology, points are assigned as follows:
No abnormality - 0
Compression - 1
Burst - +1 = 2
Distraction - 3
Rotation/translation - 4
With respect to the DLC, points are assigned as follows:
Intact - 0
Indeterminate - 1
Disrupted - 2
With respect to neurologic status, points are assigned as follows:
Intact - 0
Root injury - 1
Complete cord injury - 2
Incomplete cord injury - 3
Continuous cord compression in setting of neurologic deficit - +1
The AOSpine organization used a consensus process among clinical experts to develop a subaxial cervical spine injury classification system.[10] This system is based on the following three injury morphology types:
Compression injuries (A)
Tension band injuries (B)
Translational injuries (C)
There are additional descriptions for facet injuries, as well as patient-specific modifiers and neurologic status.[11] Initial assessment showed this classification system to have good intraobserver and interobserver reliability for all injury subtypes.
Routine laboratory studies for trauma patients are included for those with subaxial cervical spine trauma. A complete blood count (CBC), urinalysis, and serum electrolyte levels and chemistries are obtained as the individual case dictates.
A blood type and screen or crossmatch for packed or whole blood may be necessary, depending on the concomitant injuries and vital sign assessment.
When spinal cord injury (SCI) is present, neurologic impairment may impede evaluation of other injuries, including intra-abdominal trauma to solid organs. Liver and renal function testing may be of benefit in these situations.
The cross-table lateral radiograph (see the image below) has been the criterion standard for evaluating subaxial cervical alignment. This must include visualization of the cervicothoracic junction. A swimmer's view may be necessary to complete the evaluation of this area, but if body habitus precludes adequate visualization, computed tomography (CT) of the area is mandatory to exclude neck injury. Additional views include the anteroposterior (AP) and open-mouth odontoid radiographs.[12, 13]
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Lateral film of a C5 burst/teardrop fracture.
Whereas a CT scan is helpful in imaging the cervicothoracic junction, it is extremely beneficial in identifying posterior-column injuries such as lamina or facet fractures.[14] (See the images below.)
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Sagittal CT scan of C5 burst fracture.
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Axial CT scan of C5 burst fracture.
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Axial CT scan of C7-T1 fracture/dislocation.
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Sagittal CT of C7-T1 fracture/dislocation.
Guidelines published in 2013 by the American Association of Neurological Surgeons (AANS) did not recommend radiography of the cervical spine for awake, asymptomatic patients who have no neck pain or tenderness, whose neurologic examination is normal, who do not have an injury that would hinder accurate evaluation, and who can complete a functional range of motion examination.[15] High-quality CT of the cervical spine is recommended for the awake, symptomatic patient, with a three-view spine series recommended if high-quality CT imaging is not available.
Magnetic resonance imaging (MRI) is particularly useful in demonstrating injuries to the neural elements, especially the spinal cord. Traumatic disk herniations are well delineated on MRI, but routine use of this study may not contribute to the treatment regimen chosen for these injuries. If the neurologic level of injury does not match the area of injury identified by standard radiographs, this is another indication for MRI. (See the image below.)
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MRI of C7-T1 fracture/dislocation.
Some have found MRI of the cervical spine to be helpful in determining ligamentous injury, but its application to justifying surgical intervention is not clear from available literature.
There is controversy on the management of unilateral and bilateral facet dislocations, because neurologic deterioration has been reported after closed reduction. Eismont suggested that the mechanism of this neurologic decline is cord compression at the time of reduction by large, associated disk herniations.[16] He recommended that MRI be done before reduction and proposed that if a large disk herniation is found, anterior removal be done before reduction so as to avoid a catastrophic event. This approach, however, remains debatable; some surgeons believe that reduction should not be delayed in a neurologically incomplete or deteriorating patient but should be performed on an urgent basis.
If the patient is neurologically intact and alert, it seems reasonable to perform MRI if this is not otherwise contraindicated. Each clinical situation must be assessed individually. In the patient with multiple injuries, including life-threatening injuries that require stabilization in the operating room, reduction could be performed without the delay necessary to obtain an MRI scan.
Magnetic resonance angiography (MRA) may be indicated when associated vertebral artery injury is suspected. This may occur in the severely degenerative cervical spine or when fractures through the foramina transversarium are present.
The primary indications for surgical intervention in subaxial cervical injuries include the following:
Malalignment of the spine, with or without neurologic deficits
Progressive neurologic deterioration in the face of persistent compression from bone or disk fragments
Although malalignment can be managed initially with cervical tong traction, definitive surgical stabilization, with or without decompression, generally is required.
Anterior-column trauma may result from axial loading injuries in combination with flexion, extension, or rotational moments. Typically, the burst fracture or teardrop variant occurs with translation of bony fragments into the spinal canal.[17, 18, 19] Direct trauma to the cord may result in incomplete or complete spinal cord injury (SCI) syndromes. Most frequently, anterior SCI is accompanied by loss of motor function and pain and temperature sensations, along with preservation of proprioception and vibratory sensation.
Central cord syndrome refers to the clinical picture of greater upper-extremity involvement than lower-extremity motor deficits. Return of function follows a distinct pattern of lower-extremity improvement, followed by upper proximal muscle improvement, followed finally by distal upper-extremity function, which may recover incompletely. Brown-Séquard syndrome is typically a hemisection of the spinal cord, with loss of ipsilateral motor function below the level of involvement; contralateral pain; and temperature loss. This is generally seen with penetrating injuries (eg, gunshot wounds).
Posterior injury may result in unilateral or bilateral facet fracture, dislocation, or both. Isolated spinous process injury is usually a stable injury and does not require surgical attention. Unilateral facet dislocations may be the most difficult to reduce by closed means, and open reduction and stabilization are often necessary.[20] Radiculopathies with or without cord damage may be seen with the unilateral facet injury. Bilateral facet dislocations have the highest incidence of SCI, with both incomplete and complete syndromes appearing.
Reduction of subaxial malalignment must be undertaken with caution in the presence of certain concomitant disk herniations. Those that displace posteriorly and inferiorly have been reported to cause worsening neurologic deficits with both open and closed reductions. In the awake and cooperative patient, it is possible to carry out cautious reduction while performing serial neurologic examinations. In the case of intoxication or closed head injury, in which examination may be impeded, magnetic resonance imaging (MRI) may prove prudent to avoid catastrophic neurologic injury.
If such a disk herniation is identified before reduction, it can be removed anteriorly, and reduction then can be performed safely. This has been described in both unilateral and bilateral facet dislocations.
Guidelines on treatment of subaxial cervical spine injuries are available from the American Association of Neurological Surgeons (AANS; see Guidelines).[21]
Medical management involves treating the multiple traumas and, more specifically, treating concomitant neurologic injury. The use of steroids for neurologic injury has become standard to prevent secondary causes of spinal cord damage, such as release of toxic peroxidases, and to minimize associated local edema. Steroids are thought to help stabilize neural membranes, to prevent uncontrolled intracellular calcium influx, to decrease lysosomal enzyme action, and to diminish swelling and inflammation.
In three National Acute Spinal Cord Injury Study (NASCIS) reports, the recommended management for patients with SCI presenting within 3 hours of injury was a 30 mg/kg loading dose of methylprednisolone given intravenously (IV) over 1 hour, followed by 5.4 mg/kg/hr for the next 23 hours. If the patient presents more than 3 hours but less than 8 hours post injury, the 5.4 mg/kg/hr dosage is extended for 48 hours following the same loading dose. Steroid treatment does not seem to be beneficial if begun more than 8 hours post injury or after nerve root trauma.[22, 23, 24, 25]
The Spine Focus Panel, in a 2001 review of the literature, continued to recommend the steroid protocol on the basis of its modest neuroprotective effects, its favorable risk-to-benefit ratio, and the lack of alternative therapies. However, the use of steroids in penetrating injuries, especially gunshot wounds, has not proved beneficial.[26]
The use of steroids has been questioned because of its risk-to-benefit ratio. Complications, including increased risk of infection, stress ulcers, hyperglycemia, and compromised healing of surgical and other wounds, have prompted many clinicians to avoid steroids in the case of SCI. A committee of neurosurgeons, orthopedic surgeons, emergency physicians, and physiatrists, at the request of the Canadian Spine Society and the Canadian Neurosurgical Society, concluded the following[27, 28] :
There is insufficient evidence to support the use of high-dose methylprednisolone within 8 hours following acute closed SCI as a standard or as a guideline for treatment
Methylprednisolone prescribed as a bolus IV infusion of 30 mg/kg of body weight over 15 minutes within 8 hours of acute closed SCI, followed 45 minutes later by an infusion of 5.4 mg/kg of body weight per hour for 23 hours, is a treatment option for which there is weak clinical evidence.(level II, III)
There is insufficient evidence to support extending methylprednisolone infusion beyond 23 hours if this is chosen as a treatment option
These recommendations were presented to the two sponsoring societies and adopted.
Prospective studies also assessed the effect of lazaroids and gangliosides on ultimate neurologic outcome, without documenting any significant lasting effects. The effectiveness of these agents was shown in the mild and partial injury groups, not in complete SCI.[29] Other modalities of treatment have included hypothermia, calcium-channel blockers, and naloxone, but these treatments have failed to show helpful effects.
The use of histamine-2 (H2) blockers (eg, famotidine and ranitidine) generally is recommended to prevent stress ulceration from SCI and for prophylaxis when the steroid protocols are followed.
Prophylaxis for deep vein thrombosis (DVT) and pulmonary embolism is of particular concern in the neurologically compromised patient. Rates for DVT in complete injuries range from 30% to 90%; DVT warrants medical and/or mechanical treatment. This may include low-molecular-weight heparin (LMWH), oral warfarin, intermittent compression devices for the lower extremities, or vena cava filters.
Experimental therapies
Restoration of spinal cord function after injury remains a major challenge to those treating paralyzed victims. Although prevention and treatment of secondary cord damage continues to be a primary objective, the ability to reverse established cord dysfunction is a major goal. Attempts to reestablish neural recovery have focused on modification of the injured tissue through implantation of acellular guiding prosthesis, fetal tissue, and glial cells.
The activation of intrinsic neural capacities through gene therapy or by delivering a host of neurotropic substances such as nerve growth factor or brain-derived neurotrophic factors is being explored experimentally. The use of stem cells and trials using olfactory glial cells remain on the horizon. Olfactory glial cells are the only neurons able to replicate in adult life. They are capable of crossing scar tissue as well as bridging the gap between the peripheral nervous system and the central nervous system (CNS).
Potassium channel blockade has been used in the clinical arena and has been successful in helping as many as one third of patients with chronic SCIs. The drug 4-aminopyridine has been most effective in patients with incomplete SCIs.[30] It is believed to work through blockage of the fast A-type potassium channels that increase the safety factor of conduction across demyelinated or thinly remyelinated internodes or by increasing influx of calcium at presynaptic terminals, which improves neural transmission.
Initial surgical management focuses on the specific injury encountered. Such injuries may be classified into the following three categories:
Those involving primarily the anterior column or vertebral body
Those involving the posterior column with pedicle, facet, or lamina injury
Those involving both columns
Spinal realignment generally is emphasized. This begins with the application of cervical tongs and continues by serially increasing traction until normal spinal alignment is achieved and bony compression is reduced. (See the image below.) Gardner-Wells tongs have been the criterion standard for years because they are easy to apply and can withstand great weight until reduction is obtained. Tongs or halos compatible with magnetic resonance imaging (MRI) can also be used and have the advantage of allowing urgent MRI when appropriate.
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Reduction of C5 burst fracture after tongs traction.
If the injury primarily involves the anterior column, a Smith-Robinson or standard anterior approach to the spine is used to allow anterior decompression and reconstruction with either allograft or autograft iliac crest or fibula, followed by stabilization with anterior locking plates.
The posterior approach is indicated when the pathoanatomy involves the posterior elements and is the basic midline approach with muscle retraction off the cervical spine to the lateral aspect of the facet joints bilaterally.
Occasionally, a dual approach is necessary to remove an offending disk fragment anteriorly prior to reduction, followed by posterior stabilization with anterior reconstruction. These global injuries are usually quite unstable, and they benefit from both anterior and posterior reconstruction.[31]
Preparation for surgery
In-hospital care of the patient with a cervical spine injury should be meticulous in the preoperative period. These patients are at risk for pulmonary problems secondary to concomitant injuries and to immobilization. Gastrointestinal (GI) bleeding has been reported in as many as 40% of patients and is most common around 10 days following injury. This can be aggravated by corticosteroid use and can be treated with H2 blockers and early enteral feedings.
These patients are also at risk for developing DVT secondary to immobilization. The incidence of DVT has been reported to be as high as 95%, and DVTs are clinically relevant in as many as 35% of people. Some form of anticoagulation and compression boots should be used. Skin breakdown due to immobilization is also a problem and should be treated aggressively with pressure relief and wound care.
Timing of surgical intervention
The above preoperative problems and their association with immobilization have contributed to controversy in the timing of surgical intervention. Proponents exist for both early and late surgical intervention.[32] Some studies showed worsening after surgical intervention within the first 5 days after injury. These studies reported increased mortality and neurologic deterioration, concluding that a 1-2 week delay in operative intervention is best. However, other studies showed that neurologic damage is affected not only by the degree of cord compression but also by its duration. These studies led to recommendations for urgent decompression.
Most surgeons now advocate early intervention, recognizing that patients are better candidates for surgery in this early window of opportunity before other complications occur. The best reasons for early surgical intervention are to avoid preoperative systemic problems, to provide rapid decompression of the injured cord, and to return to mobilization. One other important scenario is in the patient who exhibits progressive neurologic worsening: In such patients, it is generally agreed that prompt surgical decompression is absolutely necessary.
A critical review of the literature regarding preclinical and clinical evidence on the potential impact of timing of surgical decompression after traumatic spinal cord injury included 153 abstracts, of which 22 fulfilled the inclusion and exclusion criteria. The vast majority were level 4 evidence; two were level 2b. The most common definition of early surgery was 24-72 hours following SCI.
An expert panel recommended that early surgical intervention be considered from 8 to 24 hours following acute SCI. In accordance with a modified Delphi process, the following recommendations were made[33, 34] :
There is strong preclinical evidence for the biologic benefits of early surgical decompression in animal SCI models
Decompression should be performed within 24 hours when medically feasible; the optimal timing of surgical decompression, as well as whether surgery is indicated at all in patients with central cord syndrome injury, remains unclear
Early spinal cord decompression has clinical, neurologic, and functional benefits
A single-center prospective cohort study by Du et al evaluated 402 patients with traumatic cervical SCIs (C3-7) who underwent decompression surgery of the spinal cord either early (< 72 hr after injury; n = 187) or late (≥ 72 hr after injury; n = 215).[35] Each group was divided into A0, A1-4, B, C/F4 and F1-3 subgroups on the basis of the AOSpine subaxial cervical spine injury classification system. The investigators found that whereas aggressive early decompression was not required for type A and F1-3 fractures, type B and type C/F4 fractures should receive early surgical treatment for better clinical outcomes.
Operative details
When the patient is taken to the operating room, certain issues must be addressed. If the patient has been in traction or a halo for reduction of the spine, this must be maintained in the transfer to the operating table and while the patient is on the operating table. This sometimes requires an awake patient, nasal intubation, or both with meticulous handling of the cervical spine during the entire process. Thus, the surgeon, anesthesiologist, and nursing staff must all be working in concert to ensure the patient's safety.
The operative approach obviously dictates whether the patient is prone or supine, and in some instances, both positions are needed for the combined approach. Whatever position is used, the hips, knees, shoulders, hands, and feet should all be well padded to prevent pressure sores and peripheral nerve palsies. The Stryker frame and Jackson frame are operating beds designed with a pulley to facilitate traction of the cervical spine. They also are designed with removable pads for patient positioning, and some are equipped with a turning frame to allow the patient to be spun safely from the supine to the prone position and back.
The indications for spinal cord monitoring are also somewhat controversial among surgeons. Somatosensory evoked potentials (SSEPs) offer a safe, noninvasive, and continuous technique for assessing the functional integrity of the spinal cord. Several reports suggested that changes in evoked potentials are predictive of neurologic change in the patient. When a signal deformity is detected, it can be checked with a wake-up test to ensure its accuracy. However, the delayed nature of the change makes these tests of limited efficacy in preventing intraoperative injury.
A major problem with the technique is that multiple false-positive and false-negative results have been reported. In addition, monitoring is only as good as the skill of the personnel performing it. In summary, SSEPs and motor-evoked potentials (MEPs) may have some benefit in the neurologically intact patient in whom significant intraoperative manipulation of the spinal column is anticipated.
Postoperatively, patients usually are maintained in some sort of cervical orthosis, depending on the quality of fixation obtained. Fixation techniques have improved dramatically in recent years. Before, most patients were placed in a halo postoperatively; now, patients are placed in only a rigid or soft collar for comfort.
The patient should be mobilized out of bed as soon as possible to prevent pulmonary and thromboembolic complications. A return to independence should be approached aggressively, with the help of a comprehensive team that includes a physical therapist, social service personnel, and family. In patients with SCI and neurologic deficit, extensive physical and emotional rehabilitation should be instituted immediately following surgery to ensure the best physical and psychological outcome for the future.[36] (See the images below.)
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Postoperative image of C5 burst fracture; note anterior and posterior fixation.
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Postoperative image of C5 burst fracture.
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Postoperative anteroposterior view of C7-T1 fracture/dislocation.
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Postoperative lateral view of C7-T1 fracture/dislocation.
Postoperative management of bowel and bladder dysfunction should include instruction in intermittent catheterizations, as well as the use of alternate-day suppositories and a high-fiber diet to assist with bowel function and avoid impaction.
Close attention to skin breakdown should include frequent turning of the patient and, as mentioned above, prompt mobilization.
Complications secondary to lower cervical spine fractures and dislocations can be divided into the following two major categories:
Fracture-dislocation–associated problems
SCI or medical-related problems, including pulmonary problems (eg, pneumonia, atelectasis, pulmonary embolus), GI problems (eg, stress ulcers), urologic problems, skin problems (eg, pressure ulcers), DVT, and psychological problems (eg, depression)
Autonomic dysreflexia is a syndrome of generalized sympathetic discharge resulting in severe headache, nausea, chills, anxiety, and sweating. Blood pressure may become dangerously high, usually as a result of bladder distention or fecal impaction. Prompt removal of the inciting stimulus and treatment of the high blood pressure are emergency measures necessary to avoid catastrophic stroke. This is a potentially lethal condition if unrecognized.
Failure to achieve realignment of the spine is among the first problems that can be encountered in dealing with this group of injuries. Whereas reduction of bilateral facet dislocations tends to be accomplished easily with cervical tongs and traction, unilateral jumped facets may be more problematic. If a reasonable attempt at reduction has been performed (50 lb [~23 kg]) or neurologic deficit is persistent or worsening, open reduction and stabilization usually can be accomplished via a posterior approach.
A unilateral root injury is more typical with these injuries. Simple inline traction does not address the rotational component of this injury, and a manipulative reduction with the patient awake can be performed once sufficient traction and flexion have disengaged the locked facet. Closed reductions are successful in about 50% of cases; the remainder require open reduction, which can be achieved easily by grasping the spinous processes and lifting and rotating the facet into place.
Because unreduced dislocations are associated with a high incidence of instability, pain, and stiffness, reduction should be performed by either closed or open means. Simple wiring or lateral mass plate fixation can maintain stability while healing occurs. Supplementing the fixation with bone grafting for arthrodesis does not always seem to be necessary, as pointed out by Levine and Roy-Camille, with plating techniques.[37]
Patients must be monitored closely for the first 4 weeks postoperatively to ensure maintenance of spinal alignment and confirm that there is no evidence of neurologic deterioration. Independence should be encouraged, and attempts to regain preinjury activity levels should begin.
Between 2 and 3 months of healing usually is expected, and radiographic signs of osseous healing should be noted in this time frame. Some patients may require up to 6 months to achieve preinjury activity levels; others, based on concomitant injuries and age, may never reach this status. Aggressive therapy should continue during this entire period. Once the injury is healed and the patient is functioning at maximal levels, return to full activity is begun.
During the follow-up period, any deterioration in neurologic function should prompt further investigation, including MRI for posttraumatic syrinx or other intrinsic or extrinsic compressive lesions.
AANS Recommendations on Classification and Treatment of Subaxial Cervical Spine Injuries
The American Association of Neurological Surgeons (AANS) issued the following level I recommendations regarding classification of subaxial cervical spine injuries[9] :
The Subaxial Injury Classification (SLIC) and severity scale is recommended as a classification system for spinal cord injury.
The Cervical Spine Injury Severity Score (CSISS) is recommended as a classification system for graded instability and fracture patterns in patients with spinal cord injury.
The Harris and Allen classifications were considered less reliable and were not recommended (level III).
The AANS also published the following level III recommendations with respect to treatment of subaxial cervical spine injuries[21] :
Closed or open reduction of subaxial cervical fractures or dislocations is recommended, with the goal of decompressing the spinal cord or restoring the spinal canal.
Stable immobilization (via either internal fixation or external immobilization) is recommended to facilitate early patient mobilization and rehabilitation.
If surgical treatment is considered, either anterior or posterior fixation and fusion is acceptable, provided that the setting does not require a particular surgical approach for decompression of the spinal cord.
Use of prolonged bed rest in traction to treat subaxial cervical fractures and dislocations is recommended if more contemporary treatment options are unavailable.
Routine use of CT and MRI is recommended in trauma patients with ankylosing spondylitis, even after minor trauma.
Posterior long-segment instrumentation and fusion or a combined dorsal and anterior procedure is recommended in patients with ankylosing spondylitis who require surgical stabilization.
Disclosure: Received income in an amount equal to or greater than $250 from: Globus medical, Nuvasive<br/>Received consulting fee from Nuvasive for speaking and teaching; Received royalty from Globus for consulting.
Coauthor(s)
Thad Andrew Riddle, MD, Orthopedic Surgeon and Partner, Georgia Bone and Joint Surgeons
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
William O Shaffer, MD, Orthopedic Spine Surgeon, Northwest Iowa Bone, Joint, and Sports Surgeons
Disclosure: Received royalty from DePuySpine 1997-2007 (not presently) for consulting; Received grant/research funds from DePuySpine 2002-2007 (closed) for sacropelvic instrumentation biomechanical study; Received grant/research funds from DePuyBiologics 2005-2008 (closed) for healos study just closed; Received consulting fee from DePuySpine 2009 for design of offset modification of expedium.
Chief Editor
Jeffrey A Goldstein, MD, Clinical Professor of Orthopedic Surgery, New York University School of Medicine; Director of Spine Service, Director of Spine Fellowship, Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, NYU Langone Medical Center
Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Medtronic, Nuvasive, NLT Spine, RTI, Magellan Health<br/>Received consulting fee from Medtronic for consulting; Received consulting fee from NuVasive for consulting; Received royalty from Nuvasive for consulting; Received consulting fee from K2M for consulting; Received ownership interest from NuVasive for none.
Acknowledgements
The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author Samuel Hu, MD, to the development and writing of this article.
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