Fractures and Spinal Stability

The determination of stability versus instability, in part, drives the decision for conservative (non-operative) or operative intervention. The presence of incomplete neurologic deficit with spinal canal compromise is also an indication for surgical intervention for traumatic spinal fractures. (48) The goals of treatment for spinal fractures include: stabilization and alignment of the vertebral column, preservation or improvement in neurologic status, and return to functional status as soon as possible. (48)

Aside from the concern for fracture stabilization and healing, spinal trauma carries with it the potential for devastating neurologic sequelae. Although the spine is uniquely designed with neuro-protection as one of its primary features, fractures are frequently accompanied by neurologic injury. Spinal cord injuries may have particular features, depending on the type of force and/or fracture. (50) Referred to as syndromes, they are differentiated by the area of cord involved and their clinical features. (51)

Anterior cord syndrome is a manifestation of injury to the anterior portion of the cord, and is characterized by paralysis below the level of injury accompanied by loss of pain and temperature sensation. (52) Since the posterior cord remains intact, there is preservation of touch, motion, proprioception, and vibration.

Central cord syndrome results from cord injury and edema, (usually in the cervical spine) and is manifested by motor and sensory deficits greater in the upper extremities and varying degrees of bowel and bladder dysfunction. (50) The elderly are more at risk for central cord syndrome because of higher incidence of stenosis caused by spondylosis and degenerative changes. (53)

Brown-Sequard syndrome is a manifestation of transverse hemisection from penetration injuries (e.g., gunshot or stab wounds) and is characterized by ipsilateral motor loss and contralateral loss of pain and temperature sensation. (52) Other causes include epidural hematoma and spinal cord tumor.

The use of methylprednisolone to protect compromised neural structures and improve functional outcomes after spinal cord injury is a controversial issue. Conclusions from the National Acute Spinal Cord Injury Studies II and III (NASCIS II and NASCIS III) have been criticized for their statistical methods and interpretation of data. (54) The criticisms include reporting only right-sided motor scores, setting arbitrary cutoffs for treatment at 3 to 8 hours post-injury instead of grading timing of treatment to neurological outcome, and exclusion of patients whose steroid therapy was discontinued from the analysis of data. Additionally, while NASCIS III incorporated outcomes important to the patient in the form of the Functional Independence Measure (FIM), these scores were not significantly different between groups at 6 weeks, 6 months, and one year post treatment. (54)

The adverse effects of methylprednisolone therapy identified in these studies included gastrointestinal bleeding, wound infection, pulmonary embolism, severe pneumonia, and sepsis. While the incidence of these adverse effects did not reach statistical significance, (there were insufficient numbers of subjects in the groups in the NASCIS II study to achieve statistical significance) complications of steroid therapy are nevertheless a very real concern.

Present recommendations from the Third National Acute Spinal Cord Injury Randomized Control Trial (55,56) are: initial bolus dose of methylprednisolone of 30-mg/kg over 15 minutes, followed by a 45-minute waiting period, then administration of a 23-hour infusion at a maintenance dose of 5.4-mg/kg/hour. If methylprednisolone is administered within 3 hours of injury, the treatment regimen should be maintained for 24-hours. If administered 3-8 hours after injury, the treatment should be maintained for 48-hours, unless complicating medical factors are present.

It should be noted that other promising pharmacologic therapies are being evaluated in the treatment of spinal cord injury, including opiate antagonists, free radical scavengers, calcium channel blockers, neutrophic factors, and 21-aminosteroids. (57-59)

Surgery for Spinal Trauma
The goals of surgical intervention in spine trauma include relieving pressure on neural structures, stabilizing unstable segments, and restoring alignment. Some of the same instrumentation systems used for elective procedures can be used in trauma applications. Additionally, larger anterior cages are used when comminuted fractures of the vertebral bodies require corpectomy and reconstruction of the vertebral body height.