Fourteen studies (1,735 patients and 298 knees) were identified: 7 RCTs, 6 case series (including 2 before-and-after studies) and 1 cross-sectional, descriptive study.
Hylan G-F 20 versus placebo injections (4 RCTs; n=386): a single course of Hylan G-F 20 produced a significant decrease of painful symptoms of knee OA (as measured on the visual analogue scale), and a short-term improvement in joint function (up to 3 to 6 months post-treatment). The authors noted that significant decreases in symptoms, compared with baseline, were often reported in both the treatment and control groups.
Hylan G-F 20 versus NSAIDs and other conventional therapies (3 RCTs; n=407): 2 RCTs found no evidence that intra-articular injections of Hylan G-F 20 were more effective than oral NSAIDs. Hylan G-F 20 did not seem to provide additional benefits over conventional therapy, as reported in one RCT.
Hylan G-F 20 versus other intra-articular hyaluronan products (1 RCT, 1 descriptive, cross-sectional study; n=169): the injection of a single course of intra-articular Hylan G-F 20 appeared to be more effective than injections of other low molecular weight hyaluronan products for the reduction of acute OA symptomatology. The authors noted that these results should be interpreted with caution because of the small sample size of the RCT and the design limitations of the other study.
Studies without a control group (2 before-and-after studies, 4 post-intervention assessment studies; n=781): 2 studies were retrospective and some did not define improvement versus baseline. Overall, around 40% of the patients showed an improvement in their symptoms, and 70% did not require a total knee arthroplasty at the end of the study (1 to 2 years).
Multiple courses of Hylan G-F 20 (5 longitudinal, descriptive studies): 2 studies were extensions of RCTs, however, the quality of the evidence was limited. The studies mainly described similar results after multiple courses in comparison with the baseline treatment course.
Safety: the available data suggested that local adverse effects of Hylan G-F 20 were in general infrequent, mild and transient. Adverse events appeared in 0 to 8.3% of the patients/knees treated in the included studies. Generally, no systemic events were reported, except for gastrointestinal events. Some studies reported mild and/or unspecific events such as itching, calf cramps and haemorrhoids. There was little evidence that patients receiving multiple courses of Hylan G-F 20 were at a greater risk of adverse events.