Objective: To determine the tolerability and short-term effectiveness of hylan G-F 20 (Synvisc) in patients with symptomatic osteoarthritis (OA) of the knee in standard clinical practice.
Research design and methods: Over 800 orthopedic surgeons in Germany recorded adverse events (AEs) for approximately five consecutive patients each following 3 weekly intra-articular hylan G-F 20 injections. Patients assessed their pain on a 4-point scale before and 3 weeks after the first injection. Potential risk factors for local AEs and possible predictors of short-term effectiveness of hylan G-F 20 were explored with logistic regression.
Results: 4253 patients were treated with 12699 injections by 840 physicians at 720 sites. Local, treatment related AEs (n = 302) were reported in 180 patients (4.2% of patients; 2.4% of injections). The most frequently reported AEs were joint effusion (2.4% of patients), joint swelling (1.3%), arthralgia (1.2%), joint warmth (0.6%), and injection site erythema (0.3%). Most AEs were mild (21.4%) to moderate (40.3%) in nature. One patient experienced a serious AE of severe swelling and synovial fluid accumulation judged as possibly treatment related. Patients < 70 years old, patients with a longer time since diagnosis, and those previously treated with visco-supplementation were more likely to experience a local AE. Pain significantly (p < 0.0001) decreased 3 weeks after the first injection compared with before treatment. Potential predictors of hylan G-F 20 short-term effectiveness were being underweight, male gender, shorter time since diagnosis, and severe baseline pain.
Conclusions: In this population of 4253 patients treated with hylan G-F 20 for OA knee pain, the overall incidence of local, treatment-related AEs was low and consistent with those reported in the current US product labeling and previously published studies. Additionally, short-term effectiveness was confirmed.