Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis

Abstract

IMPORTANCE Most clinical guidelines do not recommend platelet-rich plasma (PRP) for knee osteoarthritis (OA) because of lack of high-quality evidence on efficacy for symptoms and joint structure, but the guidelines emphasize the need for rigorous studies. Despite this, use of PRP in knee OA is increasing.OBJECTIVE To evaluate the effects of intra-articular PRP injections on symptoms and joint structure in patients with symptomatic mild to moderate radiographic medial knee OA.DESIGN, SETTING, AND PARTICIPANTS This randomized, 2-group, placebo-controlled, participant-, injector-, and assessor-blinded clinical trial enrolled community-based participants (n = 288) aged 50 years or older with symptomatic medial knee OA (Kellgren and Lawrence grade 2 or 3) in Sydney and Melbourne, Australia, from August 24, 2017, to July 5, 2019. The 12-month follow-up was completed on July 22, 2020.INTERVENTIONS Interventions involved 3 intra-articular injections at weekly intervals of either leukocyte-poor PRP using a commercially available product (n = 144 participants) or saline placebo (n = 144 participants). MAIN OUTCOMES AND MEASURESThe 2 primary outcomes were 12-month change in overall average knee pain scores (11-point scale; range, 0-10, with higher scores indicating worse pain; minimum clinically important difference of 1.8) and percentage change in medial tibial cartilage volume as assessed by magnetic resonance imaging (MRI). Thirty-one secondary outcomes (25 symptom related and 6 MRI assessed; minimum clinically important difference not known) evaluated pain, function, quality of life, global change, and joint structures at 2-month and/or 12-month follow-up. RESULTS Among 288 patients who were randomized (mean age, 61.9 [SD, 6.5] years; 169 [59%] women), 269 (93%) completed the trial. In both groups, 140 participants (97%) received all 3 injections. After 12 months, treatment with PRP vs placebo injection resulted in a mean change in knee pain scores of −2.1 vs −1.8 points, respectively (difference, −0.4 [95% CI, −0.9 to 0.2] points; P = .17). The mean change in medial tibial cartilage volume was −1.4% vs −1.2%, respectively (difference, −0.2% [95% CI, −1.9% to 1.5%]; P = .81). Of 31 prespecified secondary outcomes, 29 showed no significant between-group differences.CONCLUSIONS AND RELEVANCE Among patients with symptomatic mild to moderate radiographic knee OA, intra-articular injection of PRP, compared with injection of saline placebo, did not result in a significant difference in symptoms or joint structure at 12 months. These findings do not support use of PRP for the management of knee OA.

Update on Efficacy of Conservative Treatments for Carpal Tunnel Syndrome

“…PRP is a concentrate of plasma and platelets. It is widely used in many musculoskeletal indications, although limited evidence supports its ability to improve symptoms effectively [45][46][47]. Regarding nerves, animal models provide evidence for peripheral nerve injuries but the evidence in compression neuropathy is limited.…”

Ann Robinson’s research reviews—3 December 2021

“…Is platelet-rich plasma a solution looking for a problem? This small randomised trial of 288 people over 50 years old with radiographic evidence of mild to moderate knee osteoarthritis found that three weekly joint injections of platelet-rich plasma (versus placebo) resulted in no significant difference in knee pain scores or tibial cartilage volume (a measure of disease progression) over 12 months 3. Joint injection, whether with saline or platelet-rich plasma, reduced pain scores by 32-37%.…”

Intra-Articular Platelet-Rich Plasma Injections in Knee Osteoarthritis: A Review of Their Current Molecular Mechanisms of Action and Their Degree of Efficacy

“…The best outcomes were attained by individuals aged 51-65 years, with lower mechanical axis angle, and by patients with K/L stage 2 OA [38]. However, the study by Bennell et al showed that among patients with symptomatic mild-to-moderate radiographic knee OA, intra-articular injection of PRP did not result in a significant difference in symptoms at 12 months compared with saline injection (placebo) [39].…”

“…Patients with symptomatic mild-to-moderate radiographic knee OA who had intra-articular injections of PRP were not found to have improved symptoms or joint structure at 12 months. Therefore, the authors did not support use of intra-articular injections of PRP for the treatment of knee OA [39].…”

“…In patients with knee OA, LR-PRP demonstrated effectiveness in meaningful end points for functional and patient-reported outcomes at early time points [51]. Table 2 summarizes the efficacy of intra-articular PRP injections in knee OA [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51].…”