Clinical and radiographic results of expansive lumbar laminoplasty in patients with spinal stenosis

Background: In 1981, we developed a technique of expansive lumbar laminoplasty to alleviate the problems of conventional laminectomy in the treatment of spinal stenosis. The purposes of this study were to assess the long-term outcome following expansive lumbar laminoplasty and to investigate the postoperative problems. Methods: Fifty-four patients underwent expansive lumbar laminoplasty for the treatment of spinal stenosis. There were forty-three men and eleven women with a mean age of 52.6 years. The average length of follow-up was 5.5 years. Preoperatively, twenty-five patients had degenerative stenosis; thirteen, stenosis due to spondylolisthesis; twelve, combined stenosis (disc herniation and stenosis); and six, hyperostotic stenosis. (Two patients with hyperostotic stenosis and spondylolisthesis were included in both groups.) The clinical results were assessed with use of the Japanese Orthopaedic Association score, and the rate of recovery was calculated. Radiographic findings were analyzed on the basis of the cross-sectional area of the spinal canal, kyphosis, range of motion of the lumbar spine, and the rate of interlaminar fusion. Results: The average recovery rate at the time of the last follow-up was 69.2% for patients with degenerative stenosis, 66.5% for patients with combined stenosis, 65.2% for those with hyperostotic stenosis, and 54.7% for those with spondylolisthesis. The factors resulting in a poor recovery were an older age and insufficient decompression of the lateral stenosis. During the follow-up period, the Japanese Orthopaedic Association score became worse for seven patients, six patients had lesions develop at the level adjacent to the laminoplasty, and five patients had spondylolisthesis develop. Interlaminar fusion was observed in twenty-two patients (41%). Conclusions: The satisfactory results of expansive lumbar laminoplasty were maintained at an average of 5.5 years after surgery. The best indications for the lumbar laminoplasty procedure were young and active patients with central spinal stenosis. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.