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

STUDY DESIGN

Hybrid retrospective/prospective 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).

SUMMARY OF BACKGROUND DATA

A previous single-arm study reported on the safety, fusion rate, and patient outcomes associated with the use of the FFX facet cage in patients with lumbar spinal stenosis. There are no long-term studies reporting outcomes with this device compared with the use of pedicle screw fixation.

METHODS

Following a medical records review, subjects meeting the inclusion and exclusion criteria were consented to 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. Preoperative 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 2 groups for the primary composite fusion endpoint assessed with the FFX group achieving a 91% bony facet fusion rate. 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 with the FFX group (3.6%). Although both groups experienced significant improvements in VAS and ODI scores versus preoperative assessment, there was no difference between the 2 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 with PS fixation.

LEVEL OF EVIDENCE

Level III.