Comparison of Operative Time and Blood Loss with the FFX® Device Versus Pedicle Screw Fixation During Surgery for Lumbar Spinal Stenosis: A Retrospective Cohort Study

Objective: Pedicle screw (PS) placement to facilitate stability and spinal fusion following lumbar decompression surgery is associated with significant soft tissue damage and blood loss. The present study evaluated differences in operative time and blood loss between PS fixation and the use of new implantable facet fusion device (FFX®) during surgeries of patients with lumbar spinal stenosis (LSS). Methods: Patients from a single institution who underwent posterior lumbar fusion surgery for LSS with either PS fixation or the FFX device were included in this non-randomized, retrospective study. The PS group consisted of patients with LSS operated on in 2016 and the FFX group included patients operated on in 2018. Both groups excluded patients whose procedures were combined with additional implanted devices. All procedures were performed by the same surgeon. Select patient demographics, number of levels operated on, operative time and estimated operative blood loss were collected retrospectively. Differences between the two groups were assessed using the unpaired Wilcoxon two-sample test. Results: Of the 70 patients undergoing fusion surgery included in the study, there were 28 in the PS arm and 42 in the FFX arm. Mean age for the PS group was 67.5 ± 9.3 years (range 42.7 to 87.5) compared to 70.4 ± 11.5 years (range 49.7 to 86.6) for the FFX group. The PS group had a greater percentage of females (57.1%) compared to the FFX group (31.0%). The mean number of levels operated were similar between the PS and FFX groups (2.3 ± 1.1 vs. 2.2 ± 1.0, respectively). Mean operative time was significantly longer for the PS group versus the FFX group (152.5 ± 39.4 vs. 99.4 ± 44.0 minutes; p<0.001). Mean operative blood loss was also significantly greater for the PS group compared to the FFX group (446.5 ± 272.0 vs. 251.0 ± 315.9 mL; p<0.001). Differences were independent of the number of levels operated on. Conclusion: The use of the FFX device is associated with a significant reduction in both operative time and blood loss compared to PS fixation in LSS patients undergoing spinal fusion surgery.