Short-term outcomes of lever-arm-preserving lumbar laminoplasty: a prospective comparison of this novel procedure to conventional techniques

OBJECTIVE The aim of this study was to assess the short-term outcomes and safety of a novel lever-arm-preserving lumbar laminoplasty (Lap-Lap) compared with standard unilateral laminotomy for bilateral decompression (ULBD) and conventional laminectomy in patients with degenerative lumbar spinal stenosis (LSS). METHODS In a prospective study, 295 patients with severe LSS (lumbar canal stenosis, degenerative lumbar scoliosis, ossification of the ligamentum flavum, central herniation) underwent decompression with Lap-Lap (n = 77), ULBD (n = 120), or laminectomy (n = 98) and were evaluated at 1 year. Outcome measures included visual analog scale (VAS) scores for back and leg pain, the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RMDQ), and Zurich Claudication Questionnaire (ZCQ). Lumbar alignment and range of motion (ROM) were assessed preoperatively and 1 year postoperatively using radiographic measurements. To adjust for baseline differences, binary logistic regression analysis was performed for all clinical outcome measures to estimate the odds of achieving clinically meaningful improvement across surgical techniques. RESULTS Operative time was slightly longer for Lap-Lap than for ULBD but similar to laminectomy, and blood loss was minimal in all groups. All 3 groups exhibited pain relief and functional improvement at 1 year. After adjustment, low back pain VAS scores in the Lap-Lap group were comparable with those in the ULBD group and showed greater improvement than in the laminectomy group. On most measures, the Lap-Lap group achieved outcomes equivalent or superior to those of ULBD and laminectomy, with particularly greater improvements in the pain-related disorder, lumbar function, ambulation, and quality of life domains of the JOABPEQ after adjustment. ZCQ scores improved more in the Lap-Lap group than in the ULBD group, whereas RMDQ scores were comparable across the Lap-Lap, ULBD, and laminectomy groups. Lap-Lap also had the lowest complication rate. There were no significant differences in lumbar alignment or ROM across groups. CONCLUSIONS In this short-term study, Lap-Lap provided effective and symmetric bilateral decompression. These features contributed to favorable clinical outcomes, with fewer complications. Given its safety and reproducibility, Lap-Lap represents a promising minimally invasive option for treating LSS, especially in severe cases.