Prospective Pilot Study of Painful Lumbar Facet Joint Arthropathy after Intra-articular Injection of Hylan G-F 20

Objective: To examine changes in pain, disability, and medication usage over time from baseline to up to 12 months after facet joint injection of hylan G-F 20. Design: Prospective, uncontrolled, pilot study. Setting: University spine center. Participants: Fifteen patients (12 females), mean age of 57 years (standard deviation = 12.5), with a median duration of low back pain of 24 months (interquartile range = 11-66). Methods: Patients who fulfilled inclusion criteria underwent diagnostic blocks with local comparative anesthetics at one unilateral facet joint (FJ). Those with a true positive response underwent 2 1.0-mL intra-articular hylan G-F 20 injections, 10 days apart, into the painful FJ. A third hylan G-F 20 injection was offered to patients dissatisfied with the results obtained with the first 2 injections. Main Outcome Measures: Visual analog scale (VAS) (average, standing, walking), Oswestry Disability Index (ODI), SF-36, finger to floor distance (FTF), tolerance (standing, sitting, walking), analgesic usage, and patient satisfaction collected at baseline, 7-10 days, and at 1-, 3-, 6-, and 12-months follow-up. Results: Repeated measures mixed-models indicated that VAS (average, standing, walking [P all < .005]), ODI (P = .029), SF-36 (P = .013), FTF (P = .032), and sitting tolerance (P = .020) all showed significant changes from baseline up to 6 months and were not sustained at 12 months; with the exception of the baseline to 12-month difference for FTF. There was not evidence of changes over time in standing (P = .085) or walking (P = .084) tolerance. Satisfaction initially increased from baseline (0%) to 7-10 days (64%) but declined over time (36% at 12 months). As compared with baseline (80%), analgesic usage decreased nominally over time showing significant decreases at 6 months (33%, P = .0253) and increased slightly at 12 months (45%). Conclusions: Viscosupplementation for lumbar FJ arthropathy with hylan G-F 20 is associated with modest efficacy that predominately lasts up to 6 months. Limitations include a small sample size and lack of both a control and blinding. Larger, randomized, controlled studies are indicated to better clarify its clinical safety, efficacy, and utility.