Surgical outcomes of decompressive laminoplasty with spinous process osteotomy to treat lumbar spinal stenosis

Decompressive laminoplasty with spinous process osteotomy (LSPO) was developed as a less invasive procedure for lumbar decompression by Weiner et al. There are few reports extensively highlighting the surgical outcomes of LSPO. The purpose of this study was to evaluate the surgical outcomes of LSPO for lumbar spinal stenosis (LSS). In total, 23 patients with LSS were studied. All patients were followed up for more than 2 years. The Japanese Orthopedic Association (JOA) scores, the recovery rate (RR) of JOA scores, Visual analog scale (VAS) scores, responses to the JOA Back Pain Evaluation Questionnaire (JOABPEQ), sagittal alignment and segmental motion following LSPO were assessed preoperatively and 2 years postoperatively. Postoperative paravertebral muscle atrophy and bone union rates between the spinous process and the residual laminae were assessed. Preoperative and 2-year postoperative JOA scores were 13.0 points and 24.7 points, respectively (p<0.001). With respect to JOABPEQ, significant improvements were observed in pain-related disorders (p<0.05), walking ability (p<0.01), social life function (p<0.05), and mental health (p<0.05) dimensions. There were no significant differences between preoperative and 2-year postoperative sagittal alignment and range of motion. The degree of the paravertebral muscle atrophy at 2 years postoperatively was 23.0 % at spread side and 9.6 % at nonspread side (p<0.01). The fusion rate of the spinous process with the arcus vertebrae was 87%. This result reveals that LSPO could acquire the reconstruction of posterior supporting structures. We demonstrated that LSPO could be a one of the surgical options for LSS.