Low lumbar burst fractures: comparison between conservative and surgical treatments.

Twenty-two low lumbar burst fractures (L3-L5) were treated, with an average follow up of 56.2 and 39.0 months in the conservative and surgically treated groups, respectively. Twenty patients were available for review; seven were treated conservatively and 13 were stabilized surgically. All patients were evaluated clinically for work status, activity level, residual pain, and subsequent development of neurologic symptoms. Roentgenograms were reviewed for severity of initial fracture, canal compromise, and maintenance of initial correction. In general, neurologically intact patients in both groups returned to similar postinjury employment levels. Persistent back pain was found to be more disabling in the surgically treated group, in which a fusion incorporating four or five lumbar segments was performed. There was no evidence of significant loss of initial reduction, and no patients experienced late neurological compromise in the surgical group. An average follow-up kyphosis of 9.2 degrees and 31% loss of vertebral height were observed in the conservative group, while a follow-up lordosis of 1 degree and 19% loss of vertebral height were observed in the surgical group. Conservative treatment of low lumbar burst fracture is a viable option in neurologically intact patients, but loss of lordosis and vertebral height may persist. Biomechanical and anatomic characteristics of the low lumbar spine differ from the thoracolumbar region and may account for the inherent stability of these injuries. If surgery is chosen, a long fusion with distraction instrumentation should be avoided in the low lumbar spine. A short rigid fixation with pedicular instrumentation may be of greater benefit.