Posterolateral fusion versus Dynesys dynamic stabilization: Retrospective study at a minimum 5.5years' follow-up.

INTRODUCTION: Lumbar fusion is one of the most widespread techniques to treat degenerative lumbar pathology. To prevent complications such as non-union or adjacent segment degeneration, dynamic stabilization techniques were developed, but with controversial results. The aim of the present study was to compare long-term radiologic and clinical results between fusion and dynamic stabilization.

MATERIAL AND METHODS: A single-center retrospective study included patients with recurrent lumbar discal hernia or lumbar canal stenosis managed by posterolateral fusion or by dynamic stabilization associated to neurologic release. Patients were seen in follow-up for radiological and clinical assessment: visual analog pain scale (VAS), Oswestry Disability Index (ODI), Short Form-12 (SF-12), adjacent segment disease (ASD), and intervertebral range of motion (ROM).

RESULTS: Fifty-eight patients were included: 25 in the fusion group (FG), and 33 in the Dynesys® group (DG). VAS scores were significantly lower in DG than FG. ODI was 14.6±2.8 in DG, versus 19.4±3.3 in FG (P=0.0001). SF-12 physical subscore was significantly higher in DG. ROM was 4.1±2° in DG, vs. 0.7±0.5° in FG (P=0.001). Radiologic ASD was significantly greater in FG than DG (36% vs. 12.1%; P=0.012), without difference in clinical expression (DG, 1 case; FG, 2 cases).

CONCLUSION: Dynamic stabilization provided clinical and radiological results comparable to those of posterolateral fusion in these indications (although level L5-S1 was not studied).

LEVEL OF EVIDENCE: IV.