Complications with the variable spinal plating system.

From January 1986 to June of 1987, 40 patients underwent transpedicle fixation and fusion using the variable spinal plate system. Nineteen patients had undergone surgery at the same level or levels, and 21 patients had undergone no previous surgery. Diagnostic categories include spondylolisthesis, thoracolumbar and lumbar fractures, internal disc derangement, spinal stenosis, pseudarthrosis, mechanical instability, and fracture mal-union. Minimum follow-up has been 14 months, with the average being 20 months. Overall results showed 13 excellent, 12 good, seven fair, and eight poor. The overall complication rate was 45%. In those patients undergoing no previous surgery, it was 29%, but with those patients having previous surgery, it was 63%. Most of these complications were minor in nature and resolved before discharge. Implant failure occurred in seven patients, and consisted of screw breakage. Design modifications currently available should help minimize this complication. Although this method of internal fixation and fusion is technically demanding and has a high complication rate, it is considered to be indicated in lumbar fractures, revision of pseudarthrosis, spondylolisthesis with or without reduction, and failed surgery with marked instability.