Comparison of Three Different Paraspinous Unilateral Approaches to the Spinal Canal for Lumbar Decompression-Minimally 2-Year Postoperative Evaluation

Abstract

Background: The purpose of this study is to investigate the differences of the clinical results and imaging findings among three different bilateral decompression via unilateral approach with a minimum 2-year follow-up period. Methods: Thirty consecutive patients with lumbar spinal canal stenosis who had undergone bilateral decompression via 3 different unilateral paraspinous approaches with a minimum 2-year follow-up period were chosen retrospectively for groups A (conventional open surgery), B (mini open surgery), and C (micro-endoscopic surgery). The clinical results and imaging findings of these three groups were then investigated. Results: A significant difference in length of incision and intraoperative blood loss per level decompressed was seen with group A>B>C. Operative time per level decompressed was longer in group C than in groups A or B. Japanese Orthopaedic Association (JOA) score recovery rate was lower in group B than in group C. The change ratios of cross-sectional area (CSA) of the ipsilateral and contralateral multifidus were smaller in group A than in groups B or C. Ipsilateral facet joint preservation was less in group A than group C, and contralateral facet joint preservation was less in group A than in groups B or C. The difference in change in slippage was greater in group A than in group C. Conclusion: This study revealed that bilateral decompression via a unilateral approach using mini open or microendoscopic procedures could be better surgical interventions compared to a conventional unilateral open approach for paravertebral muscle and facet joint preservation for at least 2 years.