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. ### Competing Interest Statement Omar Houari reports receiving funding from SC Medica to support data curation for the present work. Robin Srour reports having a relative that is employed by SC Medica and being a designer for the patents associated with the FFX device. The remaining authors report no conflicts of interest associated with the present work. ### Funding Statement Funding for the study was provided by SC Medica who also was involved with the design of the study and interpretation of the data. SC Medica also provided funding support for medical writing assistance and statistical analysis. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The protocol, informed consert form (ICF), and all amendments were submitted for ethical review, and approval was obtained in writing from the Comite de protection des personnes Ile de France I, Hotel Dieu Hospital, Paris, France (IS number: 22.03424.000143). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.