Platelet-rich plasma injections are not superior to placebo injections for ankle osteoarthritis

Reference

Paget LDA, Reurink G, de Vos RJ, et al, for the PRIMA Study Group. Effect of platelet-rich plasma injections vs placebo on ankle symptoms and function in patients with ankle osteoarthritis. A randomized clinical trial. JAMA 2021;326(16):1595-1605.

Synopsis

There have been no previous published randomized trials evaluating the effectiveness of platelet-rich plasma (PRP) injections for ankle osteoarthritis. These investigators identified 100 adults, 18 years or older, who presented to orthopedic and sports medicine outpatient clinics with a score of at least 40 for ankle pain severity on a visual analog scale (range 0 to 100, where 100 = the most severe pain) and definitive x-ray evidence of tibiotalar osteoarthritis. Patients randomly received (concealed allocation assignment) 2 ultrasound-guided intra-articular injections 6 weeks apart of PRP (leukocyte poor; prepared with a widely used standard system) or matched saline as placebo. The patients also received lifestyle and exercise counseling. The individuals who assessed outcomes using a standard validated scoring tool for ankle osteoarthritis remained masked to treatment group assignment. Complete follow-up occurred for 100% of patients at 26 weeks. Using intention-to-treat analysis, mean improvement scores were similar in the PRP group and the placebo group (10 vs 11 points, respectively, on the American Orthopaedic Foot and Ankle Society scale of 0 to 100, where higher scores indicate improved function and reduced pain). Similarly, no significant between-group differences occurred in any of the multiple secondary outcomes reported.