Role of Non-Rigid Minimal Intervention Surgery in the Treatment of Degenerative Spondylolisthesis

Abstract

Introduction: Degenerative spondylolisthesis produces abnormal intervertebral movement associated with back pain. Standard surgical treatment consists of decompression with or without fusion. There is no consensus about the method of choice. Purpose of this study: avoiding decompression, a semi-rigid, minimally invasive device that reduces movement was used, removing the necessity for fusion and reducing fixation-loosening, or breakage. Methods: Analytical prospective observational study. The clinical assessment included the Oswestry Disability Index (ODI) and SF-12 (Short Form-12 Health Survey), X-Rays and MRIs (Magnetic Resonance Imaging) were taken preoperatively and at follow-up. Overall, the mean postoperative follow-up was 3.8 years. It is about a posterior intrapedicular device introduced percutaneously under X-Ray control. The device consists of two semi-rigid bars, allowing 5º multiplanar movement, and 1mm compressive-spring movement. Through manipulation and distraction, reduction of listhesis is possible, increasing disc and lateral recesses height. Results: At final follow-up, ODI and SF-12 scores significantly improved. ODI from 47.4 ± 14.9 to 22.8 ± 19.7 (p<0.001). In terms of SF-12, PHS (Physical Health Score) improved from 27.9 ± 6.3 to 37.5 ± 11.1 (p<0.001) and MHS (Mental Health Score) from 34.4 ± 11.3 to 42.7 ± 13.2 (p<0.002). The results give the message that despite generalized disc disease, a spondylolisthesis that moves is likely to be the symptomatic level. Reduction, increases spinal diameters, decompresses the neural elements and reduces movement sufficiently to stop movement-related pain. Conclusion: Semi-rigid percutaneous minimally invasive fixation is effective in the treatment of degenerative spondylolisthesis. Evident preoperative abnormal movement and reduction of the listhesis at operation are crucial factors. Due to minimal intervention and hence lack of access related injury no patient was made worse.