Introduction: Viscosupplementation is an effective treatment for patients suffering from knee osteoarthritis (OA). Most available products use 3 or 5 injection regimens. The objective of this study was to compare the safety and efficacy of a single 6 mL intra-articular administration of hylan G-F 20 with placebo.

Methods: In this prospective, multicenter, randomized, double-blind study, patients diagnosed with knee OA were randomized to one 6-mL injection of hylan G-F 20 or saline. The primary efficacy analysis (WOMAC A) was performed on the intent-to-treat population and was based on a repeated-measures model over the 26 weeks of the study. The incidence of adverse events (AEs) was collected over the study duration

Results: 253 patients were randomized to hylan G-F 20 (n=124) or placebo (n=129). Mean age was 63 years (42–84), BMI 29.4 (19.5–52.4 kg/m2), 71% were female, and all had primary knee OA of Kellgren Lawrence grade 2 (45%) or 3 (55%). Patients in the hylan G-F 20 group experienced a mean change from baseline in their WOMAC A Likert pain score (0–4 scale) over 26 weeks (primary efficacy criteria) of −0.84, which was statistically significantly different from the change reported in the placebo group (−0.69, p=0.047). Statistically significant differences favoring hylan G-F 20 were also reported for most of the secondary efficacy criteria: WOMAC A1 (estimate Odds Ratio over 26 weeks placebo/hylan G-F 20, 0.64, p=0.013), patient global assessment (0.69, p=0.029), and clinical observer global assessment (0.71, p=0.041); WOMAC B and C changes were not statistically significant between groups. There was no statistically significant difference in the use of rescue medication between the 2 groups. There were no serious AEs related to treatment. In the target knee, injection-related AEs occurred in 4.9% and 3.1% of patients for hylan G-F 20 and placebo, respectively, and treatment-related AEs occurred in 3.3% and 0.8% of patients, respectively. All target knee AEs were local pain, with or without joint swelling or effusion, and were of mild or moderate intensity.

Conclusion: This double-blind placebo-controlled study showed one injection of hylan G-F 20, possibly repeated 6 months later, was safe and provided symptomatic relief lasting up to 6 months in patients with knee OA.

Purpose: To evaluate the safety and efficacy of hylan G-F 20 viscosupplementation in patients with symptomatic osteoarthritis (OA) of the ankle.

Methods: Prospective, multi-center, open study in patients with primary or secondary grade II talocrural OA confirmed by X-ray. At baseline, patients had to score between 50–90 mm on the Patient-completed Ankle OA Pain VAS (0–100 mm). Patients received one intra-articular injection of 2 ml of hylan G-F 20 and were given an option of a second and final 2 ml injection if their pain remained between 50-90 mm on the VAS after 1, 2 or 3 months. Intraarticular injections were placed in the anteromedial portal of the ankle joint as described for ankle arthroscopy. Patients were followed for 6 months after the final injection. As rescue medication, patients could only take paracetamol up to 4 g per day, except on the day of or the day before a study visit.

All treatment emergent adverse events (AEs) were recorded. The primary efficacy endpoint was change from baseline (at final injection) in the Ankle OA Pain VAS at 3 months after the final injection. Secondary endpoints were Ankle OA Pain VAS scores at all other time-points, total Ankle OA Scale, Patient and Physician Global OA Assessment (VAS), and health-related quality of life (SF-36).

Results: Fifty-five patients (33 M; 22 F) were enrolled and received a first injection of hylan G-F 20. Twenty-four patients (44%) received a second injection. The mean age was 41 years (range 19–70). Overall, treatment with hylan G-F 20 was well tolerated. Seventeen patients (31%) had a treatment related AE of the target ankle. All were of mild or moderate intensity, the majority consisting of arthralgia and injection site pain. There was a statistically significant decrease in Ankle OA Pain VAS score from 68.0 mm at Baseline to 33.8 mm at Month 3 (p< 0.001, paired t-test), which was maintained at 6 months follow-up. The decrease was statistically significant at all time points. Patients who received only 1 injection demonstrated a greater decrease at 3 months (−42.5 mm) than patients with 2 injections (−23.5 mm). The secondary efficacy endpoints showed similar results. Of the total study population, 29 patients (53%) were responders (i.e. at least a 50% decrease in ankle OA pain) after 3 months. 64% of patients receiving 1 injection were responders after 3 months. The SF-36 questionnaire showed statistically significant improvements for both the physical and mental component scores at 3 and 6 months follow-up.

Conclusions: Treatment of OA of the ankle with intraarticular hylan G-F 20 injections is well tolerated. Treatment with hylan G-F 20 significantly decreases pain which is maintained for up to 6 months.