FRACTURE DISLOCATIONS OF THE LOWER LUMBAR SPINE: IS POSTERIOR SPINAL FUSION ADEQUATE?

Abstract

Fractures and fracture dislocations involving the lower lumbar spine and lumbosacral junction are uncommon. These high velocity injuries are often associated with neurological deficit, incontinence and dural tears. The accepted treatment has been posterior stabilisation with fusion, but loss of reduction has often been reported.

We reviewed our experience over the past four years in the management of eight male patients, two of whom sustained injuries in motor vehicle accidents and two in falls from a height. Two patients had L5/S1 traumatic spondylo-listhesis with no neurological deficit. Of the six patients with fracture dislocations of L3/4, four had translation in the sagittal and coronal planes and incomplete neurological deficit. Associated injuries in four patients included an ankle fracture, multiple rib fractures, dislocation of knee and hip, and a fracture dislocation of the midfoot.

Following satisfactory reduction, seven patients were treated by posterior spinal fusion (PSF) with instrumentation. One patient had anterior decompression, strut-grafting and posterior instrumentation. Three patients had dural tears.

In three patients treated by single segment PSF, reduction was not maintained. The maintenance of alignment was attributed to stable facet joints in one patient, two-segment instrumentation in three, and anterior strut grafting in one. One patient developed postoperative wound sepsis, which settled after repeated debridement and antibiotic treatment. Symptoms of nerve root compression improved in two of the four patients with neurological deficit.

Posterior reduction and instrumentation alone did not maintain reduction in these severe injuries. Anterior column support and multisegmental instrumentation may be required where there is marked vertebral body compression and neurological deficit.