gms | German Medical Science

Objective: Facet pain has been attributed to 15-40% of axial back pain and can be caused by osteoarthritis, synovial cysts, capsule damage and can originate in subchondral bone. Treatment is commonly by steroid injections or by neurotomy, but these solutions are usually temporary. To date, surgeons have not had a viable solution for facetogenic pain. A facet restoration device is designed to reduce pain while preserving native anatomy, with polymer wafers that conform to the concavity and convexity of the facet joint and restore a smooth gliding surface. The purpose of this study is to analyze the efficacy and safety of this bilateral facet restoration implant.

Method: 40 patients with a documented history of chronic facet pain at one to two levels were enrolled in the study. Patients were assigned to either Group I: no previous surgery at the affected or adjacent level(s) or Group II: Previous surgery not affecting the treated facet joints. A pre-op positive diagnostic facet injection within 3 months, as well as osteoarthritis < Grade III, (Weishaupt et al) were required. VAS (back and leg), Oswestry (ODI), X-rays (including F/E) and pain medication use were collected at pre-op, 6 weeks, 3, 6, 12 and 24 months post-op. Radiographs and CT/MRI were collected pre-op.

Results: Of 40 patients enrolled, 38 were implanted, including 4 patients having a 2-level surgery. To date, 20 and 6 patients have completed 12- and 24-month follow-up respectively, and early results appear indicative of 24-month clinical outcomes. At 12 months, groups I and II showed combined improvement from a mean pre-op VAS of 77.2mm (±13.6) to a mean of 46.2mm (±33.5) (p=0.003), and mean pre-op ODI of 58.2% (±12.7%) to a mean of 39.9% (±22.7%) (p=0.004). VAS reduction appears greater for Group I than for Group II (previous surgeries), likely as a result of comorbidities from their previous LBP. Overall complication rates were low.

Conclusions: Significant improvements in function and pain outcomes were seen at all follow-up time periods for both groups; initial data suggest those outcomes are indicative of 24-month results. Continued follow-up will determine Long-term safety and efficacy. This prospective study suggests that a facet restoration implant is a viable surgical treatment for chronic facet pain.