Anterior and posterior stabilization of the spine following vertebral body resection. A postmortem investigation.

Postmortem examination of a spine, which had been instrumented anteriorly at one level and posteriorly at another following vertebral body resections, showed that the posterior instrumentation was more effective in resisting torsion. Postmortem examination of a second case, where the anterior fixation had been strengthened by the addition of cement studs in the vertebral end-plates and a paravertebral modified and strengthened Zielke screw/rod system, showed this second anterior system to be an improvement for resisting torsion following the resection of one vertebral body. Anterior interbody devices become enveloped in a firm smooth fibrous capsule. A preliminary experiment on a cadaver spine had shown that anterior interbody fixation was better than posterior instrumentation for resisting flexion-compression forces.