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

Abstract

ObjectiveThe 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).MethodsA 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.ResultsA 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.ConclusionThe 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.