Some have estimated that 10% of men and 13% of women older than 60 years of age suffer from symptomatic knee osteoarthritis (OA). Recently, platelet rich plasma (PRP) injections have been suggested as an effective intervention, although there exists little high-level evidence evaluating the efficacy of this technique. This study was designed to better understand the efficacy of PRP for the treatment of knee OA.
METHODSThis FDA sanctioned, prospective, randomized, double-blind, parallel group study involved patients with knee OA, randomized to receive either leukocyte-poor PRP autologous conditioned plasma (ACP) or saline for a series of three, weekly injections. The primary efficacy outcome measures were the change in pain, joint stiffness and physical function, as measured using the WOMAC at baseline, weeks one and two, and months two, three, six and 12.
RESULTSLower overall WOMAC scores were found in the treatment group as compared to the placebo group starting at two weeks, and remaining statistically significant throughout the duration of the study. In addition WOMAC subgroups for pain, stiffness and physical function were all significantly better in the treatment group than in the placebo group at 12 months.
CONCLUSIONThis prospective study of patients with knee OA found that leukocyte-poor PRP autologous conditioned plasma could provide significant improvement in pain, stiffness and function, starting at two weeks and sustained for 12 months.