Prognostic Factors of Surgical Outcome after Spinous Process-Splitting Laminectomy for Lumbar Spinal Stenosis

STUDY DESIGN: A retrospective case review. PURPOSE: To assess the clinical and radiographic outcomes and identify the predictive factors associated with poor clinical outcomes after lumbar spinous process-splitting laminectomy (LSPSL) for lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: LSPSL is an effective surgical treatment for LSS. Special care should be taken in patients with degenerative lumbar scoliosis (DLS). METHODS: A consecutive retrospective case review of patients undergoing LSPSL for LSS with a minimum 2-year follow-up was performed. Mild DLS and mild degenerative spondylolisthesis (DS) were included in the study. The Japanese Orthopedic Association (JOA) score and recovery rate were reviewed. Poor clinical outcome was defined as a recovery rate or =5 mm was found in 8 of 24 patients (33%) in the DS group. A progression of curvature > or =5degrees was found in 5 of 14 patients (36%) in the DLS group. The progression of scoliosis and slippage did not influence the clinical outcome. CONCLUSIONS: The clinical and radiographic outcomes of LSPSL for LSS were favorable. Pre-existing DLS was significantly associated with poor clinical outcome.

Comparison of Spinous Process-Splitting Laminectomy versus Conventional Laminectomy for Lumbar Spinal Stenosis

STUDY DESIGN: Seventy-five patients who had been treated for lumbar spinal stenosis (LSS) were reviewed retrospectively. PURPOSE: Invasion into the paravertebral muscle can cause major problems after laminectomy for LSS. To address these problems, we performed spinous process-splitting laminectomy. We present a comparative study of decompression of LSS using 2 approaches. OVERVIEW OF LITERATURE: There are no other study has investigated the lumbar spinal instability after spinous process-splitting laminectomy. METHODS: This study included 75 patients who underwent laminectomy for the treatment of LSS and who were observed through follow-ups for more than 2 years. Fifty-five patients underwent spinous process-splitting laminectomy (splitting group) and 20 patients underwent conventional laminectomy (conventional group). We evaluated the clinical and radiographic results of each surgical procedure. RESULTS: Japanese Orthopaedic Association score improved significantly in both groups two years postoperatively. The following values were all significantly lower, as shown with p-values, in the splitting group compared to the conventional group: average operating time (p=0.002), postoperative C-reactive protein level (p=0.006), the mean postoperative number of days until returning to normal body temperature (p=0.047), and the mean change in angulation 2 years postoperatively (p=0.007). The adjacent segment degeneration occurred in 6 patients (10.9%) in the splitting group and 11 patients (55.0%) in the conventional group. CONCLUSIONS: In this study, the spinous process-splitting laminectomy was shown to be less invasive and more stable for patients with LSS, compared to the conventional laminectomy.