The use of cervical interfacet devices and related clinical outcomes.

Purpose: The purpose of this study was to investigate the outcomes of minimally invasive PCF using an interfacet joint fusion cage.

Methods: The inclusion criteria consisted of patients who underwent a PCF using an interfacet device (Cavux, Providence Medical Technology Inc.) at a single institution and were at least 6 months postoperative. Charts were reviewed for pre-, intra- and postoperative data including arm and neck pain scores, Neck Disability Index (NDI), complications, and reoperations.

Results: A consecutive series of 51 patients were included. Mean age was 54.9 years and 72.6% of patients (n = 37) were female. Most patients (n = 39, 76.5%) had a prior anterior cervical fusion resulting in pseudarthrosis. In total, 157 interfacet devices were implanted in 79 levels. There was statistically significant improvement from pre- to postoperative arm pain (3.8 vs. 2.4), neck pain (6.2 vs. 4.0), and NDI (42.2 vs. 34.9). With the exception of neck pain, these changes would not generally be considered clinically relevant. Ten (19.6%) reoperations occurred, with 4 (7.8%) involving interfacet device removal. The removals were due to: nonunion, device malpositioning, osteophytic overgrowth, trauma, and implantation of additional posterior instrumentation.

Conclusion: Performing a minimally invasive facet fusion may be an effective option for treating patients with a history of nonunion. Although the reoperation rate was high in this challenging cohort, only 4 out of 10 reoperations required device removal. More research is warranted to refine indications for this procedure and review larger samples of patients.