title: Surgical outcomes of modified lumbar spinous process-splitting laminectomy for lumbar spinal stenosis.
abstract: The lumbar spinous process-splitting laminectomy (LSPSL) procedure was developed as an alternative to lumbar laminectomy. In the LSPSL procedure, the spinous process is evenly split longitudinally and then divided at its base from the posterior arch, leaving the bilateral paravertebral muscle attached to the lateral aspects. This procedure allows for better exposure of intraspinal nerve tissues, comparable to that achieved by conventional laminectomy while minimizing damage to posterior supporting structures. In this study, the authors make some modifications to the original LSPSL procedure (modified LSPSL), in which laminoplasty is performed instead of laminectomy. The purpose of this study was to compare postoperative outcomes in modified LSPSL with those in conventional laminectomy (CL) and to evaluate bone unions between the split spinous process and residual laminae following modified LSPSL. Forty-seven patients with lumbar spinal stenosis were enrolled in this study. Twenty-six patients underwent modified LSPSL and 21 patients underwent CL. Intraoperative blood loss and surgical duration were evaluated. The Japanese Orthopaedic Association (JOA) scale scores were used to assess parameters before surgery and 12 months after surgery. The recovery rates were also evaluated. Postoperative paravertebral muscle atrophy was assessed using MRI. Bone union rates between the split spinous process and residual laminae were also examined. The mean surgical time and intraoperative blood loss were 25.7 minutes and 42.4 ml per 1 level in modified LSPSL, respectively, and 22.7 minutes and 29.5 ml in CL, respectively. The recovery rate of the JOA score was 64.2% in modified LSPSL and 68.7% in CL. The degree of paravertebral muscle atrophy was 7.8% in modified LSPSL and 22.2% in CL at 12 months after surgery (p < 0.05). The fusion rates of the spinous process with the arcus vertebrae at 6 and 12 months in modified LSPSL were 56.3% and 81.3%, respectively. The modified LSPSL procedure was less invasive to the paravertebral muscles and could be a laminoplasty; therefore, the modified LSPSL procedure presents an effective alternative to lumbar laminectomy.
authors.affiliation: Department of Orthopedic Surgery, Chutoen General Medical Center, Shizuoka; and.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kanbara
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Yukawa
authors.forename: Keigo
authors.initials: K
authors.lastname: Ito
authors.forename: Masaaki
authors.initials: M
authors.lastname: Machino
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Kato
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D007564:Japan; D007796:Laminectomy / Q000379:methods*; D065406:Laminoplasty / Q000379:methods*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed
keywords: CL = conventional laminectomy; JOA = Japanese Orthopaedic Association; LSPSL = lumbar spinous process–splitting laminectomy; LSS = lumbar spinal stenosis; PVM = paravertebral muscle; decompression surgery; laminoplasty; lumbar spinal stenosis; lumbar spinous process–splitting laminectomy; paravertebral muscle; spinous process