Introduction There is a lack of effective non-surgical interventions for ankle osteoarthritis. Platelet-rich plasma (PRP) injections are widely used and reported to be beneficial for knee osteoarthritis. We evaluated the efficacy of PRP injections in the management of ankle osteoarthritis.

Materials and Methods In this six-center stratified, block-randomised, double-blind, placebo-controlled trial design we randomly assigned 100 patients to two treatment groups: PRP versus Placebo (saline) injected intra-articular. Patients had talocrural joint space narrowing. The primary outcome measure was the American Orthopaedic Foot and Ankle Society (AOFAS) score at 26 weeks follow-up. Secondary outcome measures included multiple Patient Related Outcome Measures assessing pain, function and quality of life.

Results A total of 48 patients were randomized to the PRP-group and 52 patients to the placebo-group. No patients were lost to follow-up for the primary outcome. Compared to baseline, the mean AOFAS score improved by 10 points in the PRP group (from 63 to 73 points; 95% CI: 6 to 14; p<0.001) and 11 points in the placebo group (from 64 to 75 points; 95% CI: 7 to 15; p<0.001). The adjusted between-group difference over 26 weeks was -1 point (95% CI, -6 to 3; p=0.56). No between group differences were seen for any of the secondary outcome measures. There was one serious adverse events in each group unrelated to the study intervention.

Conclusion In patients with ankle (talocrural) osteoarthritis intra-articular PRP injections compared with placebo injections, did not significantly improve ankle symptoms and function over 26 weeks.