Reduced postoperative wound pain after lumbar spinous process-splitting laminectomy for lumbar canal stenosis: a randomized controlled study

Abstract

Object: to reduce intraoperative damage to the posterior supporting structures of the lumbar spine during decompressive surgery for lumbar canal stenosis (LCS), lumbar spinous process-splitting laminectomy (LSPSL or split laminectomy) was developed. This prospective, randomized, controlled study was conducted to clarify whether the split laminectomy decreases acute postoperative wound pain compared with conventional laminectomy.

Methods: forty-one patients with LCS were enrolled in this study. The patients were randomly assigned to either the LSPSL group (22 patients) or the conventional laminectomy group (19 patients). Questionnaires regarding wound pain (intensity, depth, and duration) and activities of daily living (ADL) were administered at postoperative days (PODs) 3 and 7. Additionally, the authors evaluated the pre- and postoperative serum levels of C-reactive protein and creatine phosphokinase, the amount of pain analgesics used during a 3-day postoperative period, and the muscle atrophy rate measured on 1-month postsurgical MR images.

Results: data obtained in patients in the LSPSL group and in 16 patients in the conventional laminectomy group were analyzed. The mean visual analog scale for wound pain on POD 7 was significantly lower in the LSPSL group (16 ± 17 mm vs 34 ± 31 mm, respectively; p = 0.04). The mean depth-of-pain scores on POD 7 were significantly lower in the LSPSL group than in the conventional group (0.9 ± 0.6 vs 1.7 ± 0.8, respectively; p = 0.013). On POD 3, the mean serum creatine phosphokinase level was significantly lower in the LSPSL group (126 ± 93 U/L) than in the other group (207 ± 150 U/L) (p = 0.02); on POD 7, the mean serum C-reactive protein level was significantly lower in the LSPSL group (1.1 ± 0.6 mg/dl) than in the conventional laminectomy group (1.9 ± 1.5 mg/dl) (p = 0.04). The number of pain analgesics taken during the 3-day postoperative period was lower in the LSPSL group than in the conventional laminectomy group (1.7 ± 1.3 tablets vs 2.3 ± 2.4 tablets, respectively; p = 0.22). The mean muscle atrophy rate was also significantly lower in the LSPSL group (24% ± 15% vs 43% ± 22%; p = 0.004).

Conclusions: lumbar spinous process-splitting laminectomy for the treatment of LCS reduced acute postoperative wound pain and prevented postoperative muscle atrophy compared with conventional laminectomy, possibly because of minimized damage to the paraspinal muscles.