Spinous Process-Splitting Laminectomy Approach for Tumor Excision at Conus Medullaris or Cauda Equina Level Results in Satisfactory Clinical Outcomes Without Affecting Global Spinal Sagittal Alignment

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: The present study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes following tumor resection using spinous process-splitting laminectomy (SPSL) approach without fixation in patients with conus medullaris (CM) or cauda equina (CE) tumor. METHODS: Forty-one patients with CM or CE tumor (19 males, 22 females, mean age at surgery of 52.9 ± 13.0 years) were included in this study. The variations of outcome variables were analyzed in various GSSA profiles using radiographic outcomes. The clinical outcomes were assessed using Japan Orthopaedic Association (JOA) score and JOA back pain evaluation questionnaire (JOABPEQ). RESULTS: In all cases, the various GSSA parameters (sagittal vertical axis, C2–7 lordosis, T1 slope, thoracic kyphosis, T10–L2 kyphosis, lumbar lordosis [LL; upper, middle, and lower], sacral slope, pelvic incidence, and pelvic tilt) did not significantly change in the 2-years postoperative period. Moreover, age at surgery, the number of resected laminae, preoperative T12–L2 kyphosis, or LL did not affect the postoperative changes in T12–L2 kyphosis or LL, and had no statistically significant correlation among them. The scores of each postoperative JOA domain and the Visual Analogue Scale included in the JOABPEQ were significantly improved. There was no statistical significant group difference in each sagittal profile or clinical outcomes between CM and CE groups postoperatively. CONCLUSIONS: Tumor resection using SPSL approach did not affected the various GSSA parameters examined and resulted in satisfactory clinical outcomes, indicating that SPSL approach is a suitable surgical technique for patients with CM or CE tumor.