MANAGEMENT OF TRAUMATIC QUADRIPLEGIAIntroduction

Spinal cord injury (SCI) is an insult to the spinal cord resulting in a change, either temporary or permanent, in its normal motor, sensory, or autonomic function. Patients with spinal cord injury usually have permanent and often devastating neurologic deficits and disability. According to the National Institutes of Health (NIH), "among neurological disorders, the cost to society of automotive SCI is exceeded only by the cost of mental retardation."

After a suspected SCI, the goals are to establish the diagnosis and initiate treatment to prevent further neurologic injury from either mechanical instability secondary to injury from the deleterious effects of cardiovascular instability or respiratory insufficiency.

SCI terminology and classification

The International Standards for Neurological and Functional Classification of Spinal Cord Injury (ISNCSCI) is a widely accepted system describing the level and extent of injury based on a systematic motor and sensory examination of neurologic function. The following terminology has developed around the classification of spinal cord injuries:

Tetraplegia (replaces the term quadriplegia): Injury to the spinal cord in the cervical region, with associated loss of muscle strength in all 4 extremities

Paraplegia: Injury in the spinal cord in the thoracic, lumbar, or sacral segments, including the cauda equina and conus medullaris

The percentage of spinal cord injuries as classified by the American Spinal Injury Association (ASIA) is as follows:

Incomplete tetraplegia: 29.5%

Complete paraplegia: 27.9%

Incomplete paraplegia: 21.3%

Complete tetraplegia: 18.5%

The most common neurologic level of injury is C5. In paraplegia, T12 and L1 are the most common level.

Incidence:

The incidence of spinal cord injury in the United States is approximately 40 cases per million population, or about 12,000 patients, per year based on data in the National Spinal Cord Injury database. However, this estimate is based on older data from the 1990s as there has not been any new overall incidence studies completed. Estimates from various studies suggest that the number of people in the United States alive in 2010 with spinal cord injury was about 265,000 persons (range, 232,000-316,000).

Spinal cord injuries occur most frequently in July and least commonly in February. The most common day on which these injuries occur is Saturday. Spinal cord injuries also occur more frequently during daylight hours, which may be due to the increased frequency of motor vehicle accidents and of diving and other recreational sporting accidents during the day.

Racial, sexual, age-related differences in incidence

A significant trend over time has been observed in the racial distribution of persons with spinal cord injury. Since 2005, 66.5% are white, 26.8% are black, 8.3% are Hispanic, and 2.0% are Asian.

Males are approximately 4 times more likely than females to have spinal cord injuries. Overall, males account for 80.7% of reported injuries in the national database.

Since 2005, the average age at injury is 40.7 years, reflecting the rise in the median age of the general population in the United States. About 50% of spinal cord injuries occur between the ages of 16 and 30 years, 3.5% occur in children aged 15 years or younger, and about 11.5% in those older than 60 years (11.5%). Greater mortality is reported in older patients with spinal cord injury.

Other epidemiologic data

Marital, educational, and employment status of patients with spinal cord injuries are discussed below.

Marital status

Single persons sustain spinal cord injuries more commonly than do married persons. Research has indicated that among persons with spinal cord injuries whose injury is approximately 15 years old, one third will remain single 20 years postinjury. The marriage rate after SCI is annually about 59% below that of persons in the general population of comparable gender, age, and marital status.

Marriage is more likely if the patient is a college graduate, previously divorced, paraplegic (not tetraplegic), ambulatory, living in a private residence, and independent in the performance of activities of daily living (ADL).

The divorce rate annually among individuals with spinal cord injury within the first 3 years following injury is approximately 2.5 times that of the general population, whereas the rate of marriages contracted after the injury is about 1.7 times that of the general population.

The divorce rate in those who were married at the time of their injury is higher if the patient is younger, female, black, without children, nonambulatory, and previously divorced. The divorce rate among those who were married after the spinal cord injury is higher if the individual is male, has less than a college education, has a thoracic level injury, and was previously divorced.

Educational status

The rate of injury differs according to educational status, as follows:

Less than a high school degree: 39.8%

High school degree: 49.9%

Associate degree: 1.6%

Bachelors degree: 5.9%

Masters or doctorate degree: 2.1%

Other degree: 0.7%.

Employment status

Patients with spinal cord injury classified as American Spinal Injury Association (ASIA) level D are more likely to be employed than individuals with ASIA levels A, B, and C (see Neurologic level and extent of injury under Clinical). Persons employed tend to work full-time. Individuals who return to work within 1 year of injury tend to return to the same job. Those individuals who return to work after 1 year of injury tend to work for a different employer at a different job requiring retraining.

The likelihood of employment after injury is greater in patients who are younger, male, and white and who have more formal education, higher reported intelligence quotient (IQ), greater functional capacity, and less severe injury. Patients with greater functional capacity, less severe injury, history of employment at the time of injury, greater motivation to return to work, nonviolent injury, and ability to drive are more likely to return to work, especially after more elapsed time following injury.

Cost of Spinal Cord Injury

Spinal cord injury is an expensive problem, from every aspect of cost measurement. Although it is the most difficult cost to measure quantitatively, the greatest cost to society for spinal cord injury is the loss of many years of quality of life in the young population of patients who sustain these injuries, especially because improvements in rehabilitation have resulted in nearly normal life expectancy for many young individuals with a spinal cord injury. The lifetime direct medical cost of spinal cord injury is estimated to be from $630,000 to $970,000 per injured person . In the United States, the aggregate annual direct medical cost of traumatic spinal cord injury is estimated at $7.74 billion. Although high-level tetraplegia (upper cervical segments) represents only 10% of patients with spinal cord injuries, it accounts for 80% of the direct medical cost of spinal cord injury. Paraplegia accounts for 4% of the overall aggregate cost, and incomplete injuries account for approximately 15% of the costs.

Anatomical Considerations:

The spinal cord is divided into 31 segments, each with a pair of anterior (motor) and dorsal (sensory) spinal nerve roots. On each side, the anterior and dorsal nerve roots combine to form the spinal nerve as it exits from the vertebral column through the neuroforamina. The spinal cord extends from the base of the skull and terminates near the lower margin of the L1 vertebral body. Thereafter, the spinal canal contains the lumbar, sacral, and coccygeal spinal nerves that comprise the cauda equina. As a result, injuries below L1 are not considered spinal cord injuries (SCIs), because they involve the segmental spinal nerves and/or cauda equina. Spinal injuries proximal to L1, above the termination of the spinal cord, often involve a combination of spinal cord lesions and segmental root or spinal nerve injuries.

Neuropathways

The spinal cord itself is organized into a series of tracts or neuropathways that carry motor (descending) and sensory (ascending) information. These tracts are organized somatotopically within the spinal cord. The corticospinal tracts are descending motor pathways located anteriorly within the spinal cord. Axons extend from the cerebral cortex in the brain as far as the corresponding segment, where they form synapses with motor neurons in the anterior (ventral) horn. They decussate (cross over) in the medulla before entering the spinal cord.

The dorsal columns are ascending sensory tracts that transmit light touch, proprioception, and vibration information to the sensory cortex. They do not decussate until they reach the medulla. The lateral spinothalamic tracts transmit pain and temperature sensation. These tracts usually decussate within 3 segments of their origin as they ascend. The anterior spinothalamic tract transmits light touch. Autonomic function traverses within the anterior interomedial tract. Sympathetic nervous system fibers exit the spinal cord between C7 and L1, whereas parasympathetic system pathways exit between S2 and S4.

Injury to the corticospinal tract or dorsal columns, respectively, results in ipsilateral paralysis or loss of sensation of light touch, proprioception, and vibration. Unlike injuries of the other tracts, injury to the lateral spinothalamic tract causes contralateral loss of pain and temperature sensation. Because the anterior spinothalamic tract also transmits light touch information, injury to the dorsal columns may result in complete loss of vibration sensation and proprioception but only partial loss of light touch sensation. Anterior cord injury causes paralysis and incomplete loss of light touch sensation.

Autonomic function is transmitted in the anterior interomedial tract. The sympathetic nervous system fibers exit from the spinal cord between C7 and L1. The parasympathetic system nerves exit between S2 and S4. Therefore, progressively higher spinal cord lesions or injury causes increasing degrees of autonomic dysfunction.

Vascular supply

The blood supply of the spinal cord consists of 1 anterior and 2 posterior spinal arteries. The anterior spinal artery supplies the anterior two thirds of the cord. Ischemic injury to this vessel results in dysfunction of the corticospinal, lateral spinothalamic, and autonomic interomedial pathways. Anterior spinal artery syndrome involves paraplegia, loss of pain and temperature sensation, and autonomic dysfunction. The posterior spinal arteries primarily supply the dorsal columns. The anterior and posterior spinal arteries arise from the vertebral arteries in the neck and descend from the base of the skull. Various radicular arteries branch off the thoracic and abdominal aorta to provide collateral flow.

The primary watershed area of the spinal cord is the midthoracic region. Vascular injury may cause a cord lesion at a level several segments higher than the level of spinal injury. For example, a lower cervical spine fracture may result in disruption of the vertebral artery that ascends through the affected vertebra. The resulting vascular injury may cause an ischemic high cervical cord injury. At any given level of the spinal cord, the central part is a watershed area. Cervical hyperextension injuries may cause ischemic injury to the central part of the cord, causing a central cord syndrome.

Neurological Classification

Frankel Classification:

Clinicians have long used a clinical scale to grade severity of neurological loss. First devised at Stokes Manville before World War II and popularized by Frankel in the 1970's, the original scoring approach segregated patients into five categories, i.e. no function ( A ), sensory only ( B ), some sensory and motor preservation (C ) , useful motor function ( D ) , and normal (E)

ASIA Classification:

It is based on neurological responses, touch and pinprick sensations tested in each dermatome, and strength of the muscles that control ten key motions on both sides of the body, including hip flexion (L2), shoulder shrug (C4), elbow flexion (C5), wrist extension (C6), and elbow extension (C7). Traumatic spinal cord injury is classified into five categories on the ASIA Impairment Scale:

A = Complete: No sensory or motor function is preserved in sacral segments S4-S5

B = Incomplete: Sensory, but not motor, function is preserved below the neurologic level and extends through sacral segments S4-S5

C = Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have a muscle grade of less than 3

D = Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have a muscle grade that is greater than or equal to 3

E = Normal: Sensory and motor functions are normal

Definitions of complete and incomplete spinal cord injury, as based on the above ASIA definition, with sacral-sparing, are as follows:

Complete: Absence of sensory and motor functions in the lowest sacral segments

Incomplete: Preservation of sensory or motor function below the level of injury, including the lowest sacral segments

Presentation:

History and Physical Examination

As with all trauma patients, initial clinical evaluation of a patient with suspected spinal cord injury (SCI) begins with a primary survey. The primary survey focuses on life-threatening conditions. Assessment of airway, breathing, and circulation (ABCs) takes precedence. A spinal cord injury must be considered concurrently.

Perform careful history taking, focusing on symptoms related to the vertebral column (most commonly pain) and any motor or sensory deficits. Ascertaining the mechanism of injury is also important in identifying the potential for spinal injury.

The axial skeleton should be examined to identify and provide initial treatment of potentially unstable spinal fractures from both a mechanical and a neurologic basis. The posterior cervical spine and paraspinal tissues should be evaluated for pain, swelling, bruising, or possible malalignment. Logrolling the patient to systematically examine each spinous process of the entire axial skeleton from the occiput to the sacrum can help identify and localize injury. The skeletal level of injury is the level of the greatest vertebral damage on radiograph.

Complete bilateral loss of sensation or motor function below a certain level indicates a complete spinal cord injury.

Pulmonary evaluation

The clinical assessment of pulmonary function in acute spinal cord injury begins with careful history taking regarding respiratory symptoms and a review of underlying cardiopulmonary comorbidity such as chronic obstructive pulmonary disease (COPD) or heart failure.

Carefully evaluate respiratory rate, chest wall expansion, abdominal wall movement, cough, and chest wall and/or pulmonary injuries. Arterial blood gas (ABG) analysis and pulse oximetry are especially useful, because the bedside diagnosis of hypoxia or carbon dioxide retention may be difficult.

The degree of respiratory dysfunction is ultimately dependent on preexisting pulmonary comorbidity, the level of the spinal cord injury, and any associated chest wall or lung injury. Any or all of the following determinants of pulmonary function may be impaired in the setting of spinal cord injury:

Loss of ventilatory muscle function from denervation and/or associated chest wall injury

Lung injury, such as pneumothorax, hemothorax, or pulmonary contusion

Decreased central ventilatory drive that is associated with head injury or exogenous effects of alcohol and drugs

A direct relationship exists between the level of cord injury and the degree of respiratory dysfunction, as follows:

With high lesions (ie, C1 or C2), vital capacity is only 5-10% of normal, and cough is absent

With lesions at C3 through C6, vital capacity is 20% of normal, and cough is weak and ineffective

With high thoracic cord injuries (ie, T2 through T4), vital capacity is 30-50% of normal, and cough is weak

With lower cord injuries, respiratory function improves

With injuries at T11, respiratory dysfunction is minimal; vital capacity is essentially normal, and cough is strong.

Other findings of respiratory disfunction include the following:

Agitation, anxiety, or restlessness

Poor chest wall expansion

Decreased air entry

Rales, rhonchi

Pallor, cyanosis

Increased heart rate

Paradoxic movement of the chest wall

Increased accessory muscle use

Moist cough

Hemorrhage, hypotension, and hemorrhagic and neurogenic shock

Hemorrhagic shock may be difficult to diagnose, because the clinical findings may be affected by autonomic dysfunction. Disruption of autonomic pathways prevents tachycardia and peripheral vasoconstriction that normally characterizes hemorrhagic shock. This vital sign confusion may falsely reassure. In addition, occult internal injuries with associated hemorrhage may be missed.

In a study showing a high incidence of autonomic dysfunction, including orthostatic hypotension and impaired cardiovascular control, following spinal cord injury, it was recommended that an assessment of autonomic function be routinely used, along with American Spinal Injury Association (ASIA) assessment, in the neurologic evaluation of patients with spinal cord injury.

In all patients with spinal cord injury and hypotension, a diligent search for sources of hemorrhage must be made before hypotension is attributed to neurogenic shock. In acute spinal cord injury, shock may be neurogenic, hemorrhagic, or both.

The following are clinical "pearls" useful in distinguishing hemorrhagic shock from neurogenic shock:

Neurogenic shock occurs only in the presence of acute spinal cord injury above T6; hypotension and/or shock with acute spinal cord injury at or below T6 is caused by hemorrhage

Hypotension with a spinal fracture alone, without any neurologic deficit or apparent spinal cord injury, is invariably due to hemorrhage

Patients with a spinal cord injury above T6 may not have the classic physical findings associated with hemorrhage (eg, tachycardia, peripheral vasoconstriction); this vital sign confusion attributed to autonomic dysfunction is common in spinal cord injury

The presence of vital sign confusion in acute spinal cord injury and a high incidence of associated injuries requires a diligent search for occult sources of hemorrhage

Cord syndromes and nerve root injury

A careful neurologic assessment, including motor function, sensory evaluation, deep tendon reflexes, and perineal evaluation, is critical and required to establish the presence or absence of spinal cord injury and to classify the lesion according to a specific cord syndrome.

The presence or absence of sacral sparing is a key prognostic indicator. Sacral-sparing is evidence of the physiologic continuity of spinal cord long tract fibers (with the sacral fibers located more at the periphery of the cord). Indication of the presence of sacral fibers is of significance in defining the completeness of the injury and the potential for some motor recovery. This finding tends to be repeated and better defined after the period of spinal shock.

Determine the level of injury and try to differentiate nerve root injury from spinal cord injury, but recognize that both may be present. Differentiating a nerve root injury from spinal cord injury can be difficult. The presence of neurologic deficits that indicate multilevel involvement suggests spinal cord injury rather than a nerve root injury. In the absence of spinal shock, motor weakness with intact reflexes indicates spinal cord injury, whereas motor weakness with absent reflexes indicates a nerve root lesion.

ASIA has established pertinent definitions (see the following image). The neurologic level of injury is the lowest (most caudal) level with normal sensory and motor function. For example, a patient with C5 quadriplegia has, by definition, abnormal motor and sensory function from C6 down.

Sensory function testing

Assessment of sensory function helps to identify the different pathways for light touch, proprioception, vibration, and pain. Use a pinprick to evaluate pain sensation.

Sensory level is the most caudal dermatome with a normal score of 2/2 for pinprick and light touch.

Sensory index scoring is the total score from adding each dermatomal score with a possible total score of 112 each for pinprick and light touch.

Sensory testing is performed at the following levels:

C2: Occipital protuberance

C3: Supraclavicular fossa

C4: Top of the acromioclavicular joint

C5: Lateral side of antecubital fossa

C6: Thumb

C7: Middle finger

C8: Little finger

T1: Medial side of antecubital fossa

T2: Apex of axilla

T3: Third intercostal space

T4: Fourth intercostal space at nipple line

T5: Fifth intercostal space (midway between T4 and T6)

T6: Sixth intercostal space at the level of the xiphisternum

T7: Seventh intercostal space (midway between T6 and T8)

T8: Eighth intercostal space (midway between T6 and T10)

T9: Ninth intercostal space (midway between T8 and T10)

T10: 10th intercostal space or umbilicus

T11: 11th intercostal space (midway between T10 and T12)

T12: Midpoint of inguinal ligament

L1: Half the distance between T12 and L2

L2: Midanterior thigh

L3: Medial femoral condyle

L4: Medial malleolus

L5: Dorsum of the foot at third metatarsophalangeal joint

S1: Lateral heel

S2: Popliteal fossa in the midline

S3: Ischial tuberosity

S4-5: Perianal area (taken as 1 level)

Sensory scoring is for light touch and pinprick, as follows:

0: Absent; a score of zero is given if the patient cannot differentiate between the point of a sharp pin and the dull edge

1: Impaired or hyperesthesia

2: Intact

Motor strength testing

Muscle strength always should be graded according to the maximum strength attained, no matter how briefly that strength is maintained during the examination. The muscles are tested with the patient supine.

Motor level is determined by the most caudal key muscles that have muscle strength of 3 or above while the segment above is normal (= 5).

Motor index scoring uses the 0-5 scoring of each key muscle, with total points being 25 per extremity and with the total possible score being 100.

Lower extremities motor score (LEMS) uses the ASIA key muscles in both lower extremities, with a total possible score of 50 (ie, maximum score of 5 for each key muscle [L2, L3, L4, L5, and S1] per extremity). A LEMS of 20 or less indicates that the patient is likely to be a limited ambulator. A LEMS of 30 or more suggests that the individual is likely to be a community ambulator.

ASIA recommends use of the following scale of findings for the assessment of motor strength in spinal cord injury:

0: No contraction or movement

1: Minimal movement

2: Active movement, but not against gravity

3: Active movement against gravity

4: Active movement against resistance

5: Active movement against full resistance

Neurologic level and extent of injury

Neurologic level of injury is the most caudal level at which motor and sensory levels are intact, with motor level as defined above and sensory level defined by a sensory score of 2.

Zone of partial preservation is all segments below the neurologic level of injury with preservation of motor or sensory findings. This index is used only when the injury is complete.

The key muscles that need to be tested to establish neurologic level are as follows:

C5: Elbow flexors (biceps, brachialis)

C6: Wrist extensors (extensor carpi radialis longus and brevis)

C7: Elbow extensors (triceps)

C8: Long finger flexors (flexor digitorum profundus)

T1: Small finger abductors (abductor digiti minimi)

L2: Hip flexors (iliopsoas)

L3: Knee extensors (quadriceps)

L4: Ankle dorsiflexors (tibialis anterior)

L5: Long toe extensors (extensor hallucis longus)

S1: Ankle plantar flexors (gastrocnemius, soleus)

Perform a rectal examination to check motor function or sensation at the anal mucocutaneous junction. The presence of either is considered sacral-sparing.

The sacral roots may be evaluated by documenting the following:

Perineal sensation to light touch and pinprick

Bulbocavernous reflex, S3 or S4

Anal wink, S5

Rectal tone

Urine retention or incontinence

Priapism

RADIOOGICAL EVALUATION

Plain Radiography

Plain x-rays, if they show complete lateral visualization of the cervical spine and include an open mouth view, are fairly sensitive in identifying cervical spine fractures. The risk of missing significant fractures is less than 1% of patients. The sensitivity of the lateral x-ray alone is 83% and specificity is 97%. The addition of open-mouth and AP views increases the sensitivity to approximately 100%.

Cervical x-rays in a trauma patient are performed with the patient supine and secure on a backboard. The patient is not moved to position for the various views; rather, the x-ray beam and film position are adjusted to provide the desired image perspective. Opinions for the minimum number of plain x-rays necessary in trauma patients range from 0 to 7 (AP, lateral, open mouth, oblique, flexion and extension).

Accurate interpretation of the lateral cervical spine x-ray is essential, yet this interpretation may frequently be erroneous because of the stressed circumstances in an emergency setting and inexperience of the individuals responsible for initial care. The first step in interpreting x-rays is to make sure they are of adequate quality for the intended purpose. Lower-quality films significantly increase error rates. Adequate lateral cervical spine x-rays require clear visualization of the spine from the occiput to the first thoracic vertebra. If the lower cervical spine is not visualized on a lateral x-ray, a swimmer's lateral view or a CT scan can visualize this region.

The AP cervical spine view is less helpful in diagnosing acute injuries. A change in alignment of the uncovertebral joints and spinous processes can indicate an acute injury. The open mouth view is essential for excluding a C1 arch or C2 odontoid process fractures. Tomograms or a CT scan may be necessary to substitute for the open mouth view in unresponsive patients. Oblique views can identify injuries of the facet joints, pedicles, and lateral masses, particularly at the cervico-thoracic

junction. For this reason, oblique views in the trauma setting can increase the diagnostic sensitivity of cervical x-rays.

Most spine injuries occur at the junctions: cranio-cervical, cervico-thoracic, and thoraco-lumbar. They are often the most difficult to see on standard x-rays. Among these injuries, the most serious and most frequently missed is the cranio-cervical dissociation. Harris measurements based on the distance between the dens and the basion are probably the simplest and most reliable measurements for identifying cranio-cervical dissociation. Suspicion of injury and careful scrutiny of x-rays minimizes errors of missed injury.

In patients with cervical tenderness and normal plain x-rays, flexion-extension views can identify occult cervical ligamentous injury. Flexion-extension views in the acute setting of an emergency department, however, can be nondiagnostic or even dangerous. Patients in acute pain may have limited mobility related to muscle spasm, limiting cervical spine motion on dynamic views. Unsupervised or forceful flexion in a patient with an occult ligamentous injury may precipitate a neurologic injury. When necessary, flexion-extension x-rays should be performed in alert patients, under supervision, and with voluntary unassisted positioning by the patient.

Interpretation of x-rays has limitations. Knowledge of anatomy and clinical experience are important for accurate interpretation of x-rays. Landmarks for measurements can be difficult to identify. A systematic approach to reading cervical x-rays can help reduce the chances of missing an important injury. Alignment of the cervical vertebrae is assessed by examining longitudinal lines along vertebral bodies, lamina, and spinous processes. Examining alignment of the lamina in the upper cervical vertebrae is particularly helpful in excluding injuries of the cranio-cervical junction in both children and adults.

The prevertebral soft tissues can be useful as an indicator of swelling from acute hemorrhage. Increased thickness and altered contour of the pharyngeal tissue anterior to C2 (i.e., convexity instead of concavity caudal to the C1 anterior arch) suggest acute cranio-cervical injury. The prevertebral soft tissue shadow thickness, however, becomes unreliable in the presence of oropharyngeal tubes. Soft tissue swelling can occur without bony injury, and conversely, bony injuries can occur without significant soft tissue swelling. Prevertebral soft-tissue widening resolves to normal after 2 weeks in 50% of patients, and in 3 weeks in 90% of patients

Computed Tomography

CT and MRI may be useful together in determining the presence and extent of spinal column injury. MRI is superior in demonstrating spinal cord pathology and intervertebral disc herniation. CT is superior to MRI in demonstrating osseous injury. However, injuries purely localized to the transverse plane, such as odontoid fracture, can be missed on axial CT images. For these types of injuries, direct coronal CT can provide superior demonstration of skeletal features in the upper cervical spine.

Magnetic Resonance Imaging

MRI is useful for imaging soft tissues and bone. MRI can show edema and hemorrhage associated with acute spinal cord injury. Increased cord signal and parenchymal cord hemorrhage indicate poor prognosis for neurologic recovery. MRI is particularly useful for assessing the cranio-cervical

junction. Edema in the occipitocervical facet capsules and basicervical ligaments or acute cervico-medullary angulation suggests cranio-cervical injury.

MRI provides noninvasive assessment of the vertebral artery blood flow in cervical trauma, which can be frequently disrupted in cervical spine injuries. MRI angiograms are abnormal in 24% of patients (142). However, MRI diagnosis of arterial artery may not be functionally significant

PRINCIPLES OF TREATMENT

Goals of Spine Trauma Care

1. Protect against further injury during evaluation and management

2. Expeditiously identify spine injury or document absence of spine injury

3. Optimize conditions for maximal neurological recovery

4. Maintain or restore spinal alignment

5. Minimize loss of spinal mobility

6. Obtain a healed and stable spinal column

7. Facilitate rehabilitation

The goal of treatment of every spinal injury is restoration of the patient to maximal possible fun ction.In trauma care, this goal implies protecting all patients until a spinal injury is definitively excluded, or identified and treated. Caring for a trauma patient requires that associated injuries be expeditiously identified and appropriately treated. For patients sustaining a spinal column injury, the treatment focus is protecting uninjured neural tissues, maximizing recovery of injured neural tissues, and optimizing conditions for the musculoskeletal portions of the spinal column to heal in a satisfactory position.

Treatment Priorities

Errors in the initial care of patients with a spinal injury can have catastrophic or fatal outcomes. Minimizing these errors requires management of patients with a spinal injury at highly specialized centers with experienced personnel. Patients with a spinal cord injury in particular benefit from early transfer to a trauma center with a spinal cord injury unit. Early referral to a spinal cord injury center improves patient survival and neurologic recovery.

Management of spinal injuries in multiply injured patients requires concerted activity of a trauma team. Experienced field personnel, emergency department physicians, general surgeons, orthopedic surgeons, neurosurgeons, radiologists, anesthesiologists, physiatrists, and nursing personnel are integral members of this team. The overriding general principle in efficient care of trauma patients is early involvement by appropriate members of this team. Physicians ultimately assuming the long-

term management of trauma patients, frequently orthopedic surgeons and physiatrists, are particularly critical in directing optimal initial care.

Provisional Stabilization

Trauma patients require protection and immobilization of the spine until spinal injury is definitively excluded or treated. This general principle has specific patient-care implications commonly referred to as spine precautions. All trauma patients should be maintained in the supine position at strict bed rest with the bed flat, transfers with a spine board, and frequent log-rolling for decubitus ulcer prophylaxis. Alternatively, patients may be placed in a rotating frame for improved pulmonary mechanics and skin care.

Cervical injuries associated with malalignment require skull traction, except injuries with complete ligamentous disruption, usually indicated by distraction between vertebrae on imaging studies. Distraction injuries are the most unstable spine injuries. Skull traction in these patients will lead to catastrophic neurologic deterioration or even fatal vascular injury. Patients with distraction injuries are best immobilized with sandbags and tape or a halo apparatus. Even when immobilized in the halo apparatus, these patients should be maintained in strict bed rest with full spine precautions until definitive surgical stabilization.

Traction pins for skull tongs are placed in-line with the external auditory meatus, 1 cm above the pinna. Carbon fiber tongs with titanium pins should be used initially to permit subsequent MRI evaluation if necessary. Carbon fiber tongs, however, grip the skull less strongly than steel tongs. Pins in carbon fiber tongs may pull out of the skull with traction weights above 80 pounds. Pins in steel tongs can withstand traction up to 140 pounds. On occasion, if closed reduction in a cervical injury requires weights greater than 80 pounds, carbon fiber tongs may be exchanged for steel tongs before applying high weights.

Closed Reduction

Decompression of spinal cord injury should proceed as soon as the patient can medically tolerate it (175). The window of opportunity for maximal neurologic improvement through decompression may be as short as the first few hours after spinal cord injury. Patients with a spinal cord injury may have an excellent capacity for spinal cord recovery regardless of initial presentation. Reduction within the first few hours of injury may lead to dramatic improvement in neurologic status. Reduction within 2 hours of injury has been reported to reverse tetraplegia.

In cervical injuries, closed reduction can achieve decompression. Emergent attempted closed reduction is the treatment of choice for alert, cooperative patients with acute spinal cord injury from a cervical spine dislocation. In these patients MRI is not necessary before reduction and should not delay reduction. Reduction in an unconscious or unexaminable patient should be preceded by an MRI scan. In this situation, the presence of a herniated disc may be treated with surgical decompression before .

Patients with highly unstable injuries, such as craniocervical dissociation or a cervical injury that shows distraction at the injured segment, require compression for reduction, not further traction. Compression across the cervical spine can be applied by a halo vest.

Reduction improves stability, preventing neurologic deterioration in the interval preceding definitive treatment. Closed reduction can also improve neurologic recovery. Although case reports have described neurologic deterioration during reduction, larger series of closed reductions have not observed neurologic deterioration. In fact, one case in one of these series was of a patient with a large disc herniation seen on a prereduction MRI scan and resolved with closed reduction. Closed reduction also decreases the need for more complicated surgical procedures later.

Definitive Treatment

Nonsurgical Options

Closed treatment remains the standard of care for most spinal injuries. Clinical observation reports, biomechanical investigations of stability, and radiographic measurements of stability have not produced definitive recommendations applicable to specific cases in deciding closed or operative treatment. The only consistent indication for surgical treatment may be skeletal disruption in the presence of a neurologic deficit. A consistent contraindication to closed treatment is an unstable purely ligamentous spinal column injury in a skeletally mature patient. Although these injuries may heal sufficiently in pediatric patients with significant growth remaining, in adult patients the healing response does not restore sufficient strength to provide spinal column stability, regardless of the length of bed rest or external immobilization. Unstable ligamentous injuries require fusion. Osseous injuries heal adequately but require treatment to control deformity.

Closed treatment options are bed rest, halo apparatus, external orthosis, or cast. Bed rest as definitive treatment may be indicated in rare cases of patients unable or unwilling to undergo bracing or surgery because of a severe preexisting deformity, morbid obesity, medical comorbidity, or personal preference. Bed rest for the initial few weeks preceding bracing is an option for severely unstable injuries. The level of injury serves as a guide for the category of external orthosis. Most commercially available braces within each category are equivalent. Custom-molded trunk orthosis provides added rotational control. Casts can be applied in hyperextension to improve kyphosis. Bracing is continued until bone healing is sufficient for load bearing: 8 weeks in cervical injuries and 12 weeks in thoracolumbar injuries.

Surgical Options

Surgical management of patients with a spinal cord injury is based on reports of experience and observation, not rigorous clinical trials. Surgical stabilization of the spinal column can prevent further mechanical injury to the damaged cord tissue. Removing residual compressive mass effect may in addition allow better neurologic recovery. Closed treatment of unreduced injuries may lead to chronic pain requiring later surgical treatment.

The critical role of time is increasingly being recognized as potentially pivotal in affecting neurologic recovery. Early intervention in this setting is not defined in days after the injury, but rather in minutes and hours. Animal studies have suggested a potential window of opportunity in the first 3 to 6 hours after injury in which significant neurologic recovery may be possible.

Surgery in spinal injuries involves arthrodesis with two rare exceptions: odontoid fractures and C2 arch fractures. These two injuries in specific circumstances may be treated with internal fixation

(osteosynthesis). Open reduction and instrumentation may be just as effective as arthrodesis for spinal fractures. Early surgery reduces hospital stay.

Earlier studies reported high complication rates with anterior cervical surgery. Injured vertebrae are associated with injury to nearby soft tissues. Anterior interbody grafts without fixation may work for anterior cervical fusion after discectomy; they are prone to displacement if there is posterior instability or gross deformity of the vertebral body unless supplemented by fixation. Anterior plating and posterior plating are equally successful in cervical trauma. Anterior plating provides immediate stabilization even with posterior ligamentous injury. Although the strength of the fixated spine is relatively unchanged by corpectomy and anterior grafting, anterior grafting improves alignment. Fixation maintains alignment. Anterior fusion allows early mobilization, For thoracolumbar injuries, a three-column injury treated with anterior instrumentation should be either augmented with posterior instrumentation or postoperatively immobilized in a rigid external brace in the postoperative period. In burst fractures, anterior reconstruction with fixation is more stable than the posterior instrumentation systems in all loading conditions.

The choice of the operative method in thoracolumbar fractures should not be based on any hypothetical differences in reductive power. Canal clearance is most effective when carried out in the first 4 days after injury and in patients with an initial canal compromise of 34% to 66%. Percentage of encroachment decrease in posterior systems is small. Laminectomy increases deformity and neurologic deficit unless combined with internal stabilization. Traumatic dural tear should be repaired before any anterior or posterior spinal reduction maneuver.

If spinal canal decompression is the goal, this is best achieved through an anterior approach. Primary anterior decompression and fusion is preferred in an axial loading or flexion compression injury with a large midline retropulsed fragment that produces a significant neurologic deficit.

Transpedicular fixation provides solid internal fixation that is circumscribed to the injured vertebral segments. As injury progresses to involve all three structural columns, the ability of the transpedicular constructs to achieve preinjury stiffness decreases. Several reports have identified failure of fixation when thoracolumbar vertebral body fractures are treated with short-segment posterior fixation. One option to reduce risk of hardware failure before solid fusion is to augment transpedicular constructs with anterior bone grafting. However, external bracing to protect posterior fixation during healing remains an alternative to anterior surgery

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