Intra-articular Injection of Platelet-Rich Plasma Versus Placebo in Patients with Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials .

Across 12 trials, RCT evidence was examined on whether intra-articular PRP injections offer meaningful benefits for people with knee osteoarthritis. PRP was consistently more effective than saline in improving short-term pain and function, with benefits seen from 4 weeks up to 12 months. Measures such as VAS pain, WOMAC total, IKDC, and several KOOS subscales generally favored PRP, though evidence for KOOS symptom, daily living, and quality-of-life scores was weaker. Safety findings were reassuring: no serious adverse events were reported, and injection-site pain was similar between groups. Despite encouraging results, wide variation in PRP preparation and dosing created substantial heterogeneity, meaning these findings should be interpreted with caution and highlight the need for standardized, high-quality future trials.