Evaluation of the Efficacy and Safety of FFX Facet Cages Compared to Pedicle Screw Fixation in Patients with Lumbar Spinal Stenosis: A Long-Term Study

Objective: The study evaluated the long-term safety and efficacy of the FFX facet cage versus pedicle screw (PS) fixation in patients with lumbar spinal stenosis (LSS). Methods: A hybrid retrospective/prospective study design was used. Following a medical records review, subjects meeting the inclusion/exclusion criteria were consented and enrolled in the prospective arm of the study. CT-scans and dynamic X-rays were performed to assess fusion rates, range of motion and translation. Adverse events during the 2-year post-index procedure were also analyzed. Pre-operative and 2+ year Visual Analogue Scale (VAS) back and leg scores and Oswestry Disability Index (ODI) were also obtained. Results: A total of 112 subjects were enrolled with 56 patients included in the PS and FFX groups. Mean age was 63.1±11.2 and 67.1±10.9 years and the mean number of levels operated was 1.8±0.8 and 2.3±1.0 respectively for the PS and FFX groups. There was no difference between the two groups for the primary composite fusion endpoint assessed (respectively 60.0% vs. 70.9%, p=0.120). There was also no difference in postoperative complications or adverse events during the 2-year follow-up period. A higher percentage of patients in the PS group (10.7%) required reoperation compared to the FFX group (3.6%). While both groups experienced significant improvements in VAS and ODI scores versus pre-operative assessment, there was no difference between the two groups. Conclusion: The present study documents the long-term safety and efficacy of the FFX device in patients with LSS with a reduction in reoperation rate when compared to PS fixation.