A long-term (4-to 12-year) follow-up study of surgical treatment of lumbarspinal stenosis

Limited data are available about the long-term outcome of surgical treatmen t for lumbar spinal stenosis, and there is a wide variation in reported suc cess rates. There is also a controversy regarding differences in long-term outcome between patients undergoing decompressive surgery alone and those u ndergoing both decompression and fusion. The aim of this study was to evalu ate the long-term clinical outcome and possible complications of decompress ive surgery, with special reference to possible differences between patient s undergoing fusion, with or without instrumentation, and those undergoing decompression alone. All 124 patients undergoing first-time surgery for lum bar spinal stenosis between 1982 and 1991 at our department were included, and their medical records were reviewed retrospectively. Ninety-six of the patients were available for follow-up and were re-examined by an independen t investigator and assessed with a questionnaire after a mean follow-up per iod of 7.1 (range 4.0-12.2) years. Sixty-five percent of all the patients a t the follow-up were subjectively satisfied. Eighty-eight percent of the pa tients reported constant or daily leg pain preoperatively compared to 43% a t follow-up. Constant or daily low back pain was reported by 83% of the pat ients preoperatively compared to 45% at followup. Improvement in walking ca pacity was found in most patients, and only 4% of the patients who had a pr eoperatively documented maximum walking distance reported a decreased walki ng capacity. Twenty four (25%) of all patients used analgesics daily at the time of follow-up, 34 patients (35%) occasionally and 38 patients (40%) ne ver. The patients with fusions, instrumented or non-instrumented, did not d iffer significantly from the unfused patients regarding any of the above-me ntioned parameters. The results of the study showed that most patients demo nstrated a considerable improvement in walking capacity at follow-up. This improvement was significant (P < 0.001) and of clinical importance. A signi ficant improvement regarding both low back pain and leg pain was found post operatively compared to preoperatively (P < 0.001). There were no statistic al differences, judged by all the evaluated parameters, regarding the clini cal outcome between patients who were fused and those who were not. Neither were any significant differences found between instrumented fusions compar ed to uninstrumented fusions. In accordance with most other longterm follow -up studies, about two-thirds (65%) of the patients claimed a satisfactory result at follow-up.