Efficacy of Oxygen-Ozone Therapy and Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Meta-analysis and Systematic Review.

Context: This systematic review and meta-analysis evaluated the effect of the intra-articular injection of platelet-rich plasma (PRP) and oxygen-ozone therapy and provided an evidence-based methodology to treat KOA. Method: Databases, including Cochrane Library, PubMed, and EMBASE, were searched. The retrieval period was before 2021. Two reviewers performed the process of screening and data extraction. Mean differences were calculated [95% confidence interval (CI)] with an inverse-variance method and fixed effect model. Meta-analysis was performed using the latest version of STATA version 16. Results: A total of 12 studies out of 769 articles were evaluated. The mean difference of visual analog scale score between ozone and control groups in the first month after injection was -0.02 (MD, -0.02; 95% CI: -0.32, 0.28; P < 0.05). Mean differences of WOMAC pain, stiffness, and physical function score between baseline and after PRP were -3.53 (MD: -3.53; 95% CI: -4.04, -3.02; P = 0.00), -0.60 (MD: -0.60; 95% CI: -4.0 - 0.864, -0.34; P = 0.00), and -5.96 (MD: -5.96; 95% CI: -7.83, -4.09; P = 0.00). Conclusions: Our results showed that to treat knee osteoarthritis, using PRP for a longer period of 6 - 12 months after the intervention shows better clinical results, while oxygen-ozone therapy has short-term results.