Abstract
OBJECTIVE : The purpose of this study was to evaluate radiological and clinical results in patients with lumbar spinal canal stenosis due to degenerative spondylolisthesis who had undergone posterior decompressive surgery without fusion. We report our findings in 31 patients who were followed for at least 3 years after surgery. PATIENTS AND METHODS : We evaluated 31 consecutive patients who underwent posterior decompressive surgery without fusion between 2001 and 2005. The mean follow-up period was 62.3 months. Clinical results were evaluated using the Japanese Orthopaedic Association (JOA) score and the recovery rate. The radiographic parameters we assessed were the change in % slip and the slip angle on lateral neutral films, and translation and dynamic angulation on lateral flexion and extension films obtained before and after surgery. RESULTS : The symptom recovery rate assessed with the JOA scoring system was 76.6%. There was no statistically significant difference between pre- and postoperative measurements with respect to the slip angle, translation, and dynamic angulation. The postoperative % slip was statistically larger than the preoperative value (p<0.01) although the progression of slippage and instability after surgery did not affect the clinical results. We performed reoperation in 2 patients (6.5%) ; they underwent posterior decompression. None of the 31 patients required secondary fusion. Six patients had sacroiliac joint syndrome after surgery, and one patient had adjacent disorder. CONCLUSION : In the mid-term we obtained good operative results in patients who had undergone decompression without fusion to treat lumbar spinal canal stenosis due to degenerative spondylolisthesis. Our findings suggest that posterior decompression wide enough to reach the lateral recesses that avoids damage to the articular processes does not routinelv reauire spinal fusion and provides satisfactorv clinical results.
