Clinical outcome of microendoscopic posterior decompression for spinal stenosis associated with degenerative spondylolisthesis--minimum 2-year outcome of 37 patients.

A clear consensus for the optimal surgical treatment for spinal stenosis associated with degenerative spondylolisthesis (DS) has not appeared. In general, decompression and fusion are recommended. However, the symptoms of spinal stenosis are the main complaints in almost all patients with DS, and whether or not routine concomitant fusion is necessary in the surgical treatment for DS is still discussed controversially. The authors have treated almost all the patients with spinal stenosis associated with DS by microendoscopic posterior decompression (MEPD) procedures since 2001. In the present study, we examined the minimum 2-year outcome in 37 patients surgically treated with the MEPD procedures for spinal stenosis associated with DS. At the mean of 38 months after surgery, the overall results were excellent in 54% of the patients, good in 19%, fair in 13.5%, and poor in 13.5%, based on the Japanese Orthopedic Association lumbar score, a visual analogue scale, and the Roland-Morris disability questionnaire. Although the progression of spondylolisthesis and the increase of segmental sagittal motion after surgery were seen in 7 patients (19%), only one patient required secondary fusion during the follow-up period. A sufficient decompression with the preservation of the posterior structures of the spine was observed in almost the patients after surgery. In conclusion, the MEPD is a minimally invasive procedure developing a sufficient decompression with the preservation of the spinal stability. Thus, the MEPD is one of the useful procedures in the surgical treatment of spinal stenosis associated with DS. However, further follow-up studies should be performed to evaluate the long-term outcome for evaluation of the true validity of the MEPD for DS.