Revision Surgery for Spinal Stenosis Developed at the Adjacent Segment after Lumbar Fusion / 대한정형외과학회잡지

ABSTRACT

PURPOSE: To determine the factors influencing clinical results of revision surgery for spinal stenosis developed at the adjacent segment after spinal fusion. MATERIALS AND METHODS: Nineteen patients underwent revision surgery by adjacent segment disease after decompression and posterolateral fusion with pedicle screw instrumentation for spinal stenosis. The control group was matched in terms of age, sex, and number of fused segment, posterior interbody fusion. RESULTS: Oswestry disability index (ODI) was changed from 32.1 before surgery to 28.0 at the final follow up in the revision group. Compared to the improvement from 27.6 to 15.2 in the control group, there was a significant difference between both groups (p=0.002). Revision group had 1 nonunion and 2 proximal screw loosening. There was no late complication in the control group. In the revision group, 12 of 19 patients had disc degeneration before surgery at the upper lumbar segments which was not included in the fusion. They had an average 2.0 ODI improvement after revision surgery. On the other hand, 7 patients who had no degeneration at the unfused segment showed 7.4 ODI improvement. CONCLUSION: The clinical result of revision surgery for spinal stenosis at the adjacent segment after spinal fusion was less satisfactory than the primary surgery. The contributing factors were late complications and preoperative disc degeneration at the segments which was not included in the fusion.