Early Results of Spinal Fusion Using Variable Spine Plating System

Seventy-seven consecutive patients underwent application of variable spine plating (VSP) spinal plates between August 1984 and October 1985. Sixty-four percent had previous procedures at the same level or levels operated. Operative Indications were spinal stenosis, segmental instability, unstable spondylolisthesis, herniated disc with instability, pseudarthrosis, unstable fracture, and failed surgery syndrome with evidence of one of the preceding. Overall results showed 30% excellent, 30% good, 34% fair, 6% poor. There were four deep wound infections and 19 patients with one or more broken screws. Screw alignment and the angular relationship of each screw to the spinal plate are considered important technical factors in minimizing screw failure. Vigorous distraction of the vertebrae using interpedicular screws is rarely indicated. Twenty-four patients required reoperation. We feel the procedure is relatively indicated in cases of moderate to severe instability, such as some cases of spondylolisthesis, failed surgery with marked segmental instability, the obese, deconditioned patient, or cases of spinal stenosis rendered very unstable by surgical decompression, and most strongly indicated in unstable lumbar and thoracolumbar fractures.