Late vertebral body fracture after lumbar transpedicular fixation. Report of three cases.

Late-onset vertebral body (VB) fracture after lumbar transpedicular fixation has not been previously described in the literature. The authors present three cases in which VB fracture occurred several months after posterolateral fixation in patients with degenerative disease or traumatic injury. The authors suggest that postoperative osteopenia, modified load-sharing function, and intravertebral clefts were responsible for the fractures. Two women and one man were evaluated at a mean follow-up interval of 3 months. Two patients suffered recurrent lumbar pain. Radiography and magnetic resonance imaging revealed fracture of some of the instrumentation-treated VBs. These two patients underwent surgical superior or inferior extension of instrumentation. The third, an asymptomatic patient, received conservative management. The two patients who underwent reoperation made complete recoveries, and there was no evidence of further bone collapse in any case. The authors speculate that alterations in the VBs may occur following application of spinal instrumentation. In rare cases, the device can fracture and consequently lead to recurrent lumbar back pain. Recovery can be achieved by extending the instrumentation in the appropriate direction.