Low lumbar burst fractures: a unique fracture mechanism sustained in our current overseas conflicts.

Background Context: The most common location for burst fractures occurs at the thoracolumbar junction, where the stiff thoracic spine meets the more flexible lumbar spine. With our current military conflicts in Iraq and Afghanistan, we have seen a disproportionate number of low lumbar burst fractures.

Purpose: To report our institutional experience in the management of low lumbar burst fractures.

Study Design: Retrospective review.

Methods: We performed a retrospective review of medical records and radiographs for all patients treated at our institution with combat-related injuries and thoracolumbar fractures. We included all patients who had sustained a burst fracture from T12 to L5 and had at least 1-year clinical follow-up.

Results: Thirty-two patients sustained burst fractures. Nineteen patients (59.4%) had low lumbar (L3-L5) burst fractures, and 12 patients (37.5%) had thoracolumbar junction (T12-L2) burst fractures as their primary injury. Additionally, seven patients sustained less severe burst fractures at an additional level. One patient sustained burst fractures at both upper and lower lumbar levels. Of the low lumbar fractures, 52.6% had evidence of neurologic injury, two of which were complete. Similarly, in the upper lumbar group, 58.2% sustained a neurologic injury, two of which were complete. Twenty-two patients underwent surgical intervention, complicated by infection in 18%. At most recent follow-up, all but one patient with presenting neurologic injury had persistent deficits.

Conclusion: Low lumbar burst fractures are the predominant combat-related spine injury in our current military conflicts. The rigidity offered by current body armor may effectively lower the transition zone that normally occurs at the thoracolumbar junction, thereby, transferring forces into the lower lumbar spine. Increased awareness of this fracture pattern is warranted by all surgeons because of unique clinical challenges associated with its treatment. Although the incidence is increased in the military population, other surgeons may be involved with long-term care of these patients on completion of their military service.