Objective: Fusion is the standard of treatment for degenerative lumbar symptomatic instabilities. Dynamic stabilization is a potential alternative, with the aim of reducing pathological motion. Potential advantages are a reduction of surgical complexity and morbidity. The aim of this study was to assess whether dynamic stabilization is associated with a higher degree of functional improvement while reducing surgical complexity and thereby surgical duration and perioperative complications in comparison with lumbar fusion.
Methods: This was a multicenter, double-blind, prospective, randomized, 2-arm superiority trial. Patients with symptomatic mono- or bisegmental lumbar degenerative disease with or without stenosis and instability were randomized 1:1 to instrumented fusion or pedicle-based dynamic stabilization. Patients underwent either rigid internal fixation and interbody fusion or pedicle-based dynamic stabilization. The primary endpoint was the Oswestry Disability Index (ODI) score, and secondary endpoints were pain, health-related quality of life, and patient satisfaction at 24 months.
Results: Of 293 patients randomized to fusion or dynamic stabilization, 269 were available for analysis. The duration of surgery was significantly shorter for dynamic stabilization versus fusion, and the blood loss was significantly less for dynamic stabilization (380 ml vs 506 ml). Assessment of primary and secondary outcome parameters revealed no significant differences between groups. There were no differences in the incidence of adverse events.
Conclusions: Dynamic pedicle-based stabilization can achieve similar clinical outcome as fusion in the treatment of lumbar degenerative instabilities. Secondary failures are not different between groups. However, dynamic stabilization is less complex than fusion and is a feasible alternative.
Keywords: dynamic stabilization; lumbar degenerative instability; lumbar fusion; lumbar stenosis; spondylolisthesis.