Radiological Analysis of Symptomatic Complications after Bilateral Laminotomy for Lumbar Spinal Stenosis

OBJECTIVE The purpose of this study was to describe the various symptomatic complications following decompressive bilateral laminotomy for treating lumbar spinal stenosis. METHODS Out of 878 patients who underwent decompressive laminotomy from 2006 through 2008, 178 patients who were able to be followed for a minimum of 24 months were included in this study. The mean age at the time of surgery was 64.4 years (range, 38-79), and the average follow-up period was 32.7 months. The development of symptomatic complications was observed using simple radiographs and MR imaging during the follow-up period. Imaging and clinical complications were focused on postoperative spondylolisthesis, disc herniation, and facet cysts, and were analyzed according to developmenttime, the degree of symptom, and their course. RESULTS Postoperative simple radiographs revealed that eight out of 178 patients (4.4%) had developed symptomatic spondylolisthesis and six required an interbody fusion procedure. Five patients with disc herniation (2.8%) at the level of the decompressive bilateral laminotomy site underwent another operation within 24 months after the first surgery. In two patients, disc herniations developed within 1 month after surgery. Three (1.7%) out of 178 patients showed facet cysts but all symptoms were relieved by conservative treatment. Spontaneous regression of the cysts was observed during the follow-up period. CONCLUSIONS Although decompressive bilateral laminotomy for spinal stenosis is believed to effective and reduces the need for fusion, various symptomatic complications were observed after this procedure. It is important to be aware of the possibility for these various complications to improve the surgical outcome.