Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis: The RESTORE Randomized Clinical Trial

Bennell KL, Paterson KL, Metcalf BR, et al. · JAMA

Null on both co-primary endpoints at 12 months: pain change -2.1 vs -1.8 (P=.17) and medial tibial cartilage volume change -1.4% vs -1.2% (P=.81); 29 of 31 secondary outcomes also showed no between-group difference.

Population

Adults with symptomatic mild-to-moderate radiographic medial knee OA (mean age 61.9)

Intervention

3 weekly intra-articular injections of leukocyte-poor PRP

Comparator

Saline placebo injections

Limitations

Commercial low-dose LP-PRP kit (~2x concentration); dose-response advocates argue platelet dose was subtherapeutic. Rigorous blinding and follow-up (93%).