A supplementary instrumentation for posterior fusion of spine on scoliosis. A preliminary report.

A new type of compression instrumentation for posterior spondylodesis in scoliosis is presented. The innovation in the instrumentation, which is composed of a compression and transverse stabilizing system, is the use of gear teeth on the threaded rods which can be moved by a special wrench with gear teeth transmission. The advantages of the new instrument are: 1. Simplification of the operative technique. 2. Reduction of operation time. 3. Improvement of correction effect through the balanced tension of the entire compression and transverse stabilization system.