INTRODUCTION: Lumbar canal stenosis (LCS) is a common degenerative lumbar spinal disease (DLSD) widely treated by decompression surgery, also known as laminectomy. Although the symptoms (back and lower limb pain, motor weakness, numbness, and intermittent claudication) of most patients with LCS are improved after lumbar posterior decompression, a subset may experience recurrent symptoms due to DLSD progression. However, few studies have reported on postoperative degeneration and the need for reoperation in such cases. In this study, we focused specifically on the progression of lumbar spine degeneration, reoperation after laminectomy, and the related factors.
METHODS: We included 247 patients (148 men and 99 women; mean age, 73.3 years) with a mean follow-up of 2.3 years in this single-center retrospective study. Among them, 129 patients underwent bilateral partial laminectomy (BPL), 91 patients underwent lumbar spinous process-splitting laminectomy (LSPSL), and 27 underwent microendoscopic laminotomy (MEL) without concomitant discectomy for LCS, including lumbar spondylolisthesis. Progression of lumbar spine degeneration was defined as the development of disc herniation, spinal canal stenosis, foraminal stenosis, or facet joint cysts. It was characterized by acute lower limb pain and numbness, with or without intermittent claudication that developed postoperatively and accompanied by neurological symptoms matching magnetic resonance imaging findings (at the same spinal level as the initial surgery). Postoperative spinal instability was defined as slippage progression, indicated by a change of 3 mm or more between the operation and symptom onset (or the last consultation day) on standing radiographs. It was evaluated separately from the progression of degenerative lumbar spine symptoms.
RESULTS: Of all the patients, 34 (13.8%) exhibited progression of lumbar spine degeneration symptoms, with 9 (3.6%) requiring reoperation. Over 90% of new symptoms developed within 1 year of the initial surgery. The mean period from first surgery to reoperation was 18.8 ± 19.3 months in reoperation cases (the onset was an average of 14.3 ± 20.1 months postoperatively). Reoperation rates were significantly higher in patients with foraminal stenosis (P = < 0.001). Additionally, 35 patients (14.2%) exhibited slippage progression. LSPSL resulted in significantly less slippage progression (P = 0.026). Spinal canal and foraminal stenosis were significantly associated with slippage progression (P < 0.001, P = 0.010, respectively).
DISCUSSION: In the present study, we retrospectively evaluated the progression of lumbar spinal degeneration after laminectomy for LCS, the risk factors associated with it, and the need for reoperation. LSPSL reduces the incidence of canal stenosis and foraminal stenosis by suppressing postoperative spinal instability. Furthermore, the onset of symptomatic DLSD was more common within 1 year after surgery, and foraminal stenosis required reoperation in a higher proportion of cases. These findings could serve as guidance for spine surgeons in selecting the appropriate surgical methods for LCS, managing the symptoms of postoperative progression of DLSD, and evaluating the need for reoperation.