Background: Knee osteoarthritis is one of the most common joint diseases, resulting in pain and significant limitation of physical activity. Platelet-rich plasma is defined as an autologous concentration of human platelets in a small volume of plasma and some studies have shown efficacy in knee arthritis.
Objectives: To assess the effectiveness of platelet-rich plasma intra-articular injections when administered to patients with knee osteoarthritis, in terms of pain reduction and increasing mobility.
Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (latest issue), PubMed (up to 16/07/2017) and EMBASE (up to 18/07/2017). Language restriction to studies reported in English.
Selection criteria: We included published randomised controlled studies that assessed the effectiveness and/or safety of intra-articular PRP injections in treating knee osteoarthritis, with a minimum follow up of six months. Primary outcome measures were WOMAC and VAS questionnaires.
Main results: Six studies with 645 patients were included in our review. We compared the effectiveness of platelet rich plasma intra-articular injection to analgesia, exercise, HA and steroids injections in patients with knee osteoarthritis. Total WOMAC scores at up to 6 weeks, 3 months and 12 months after intervention, respectively, demonstrated statistically significant differences in favour of PRP intervention (MD -9.25, {95% CI -16.88, -1.62}, I2 68%, p= 0.08), (MD -14.83 {95% CI 18.56, -11.10}, I2 = 15%, p=0.31) and (MD -14.83 {95% CI 18.56, -11.10}, I2 = 15%, p=0.31). In addition, significant improvement in VAS scores in the PRP group were also demonstrated (MD -2.65 {95% CI {-3.43, -1.87}, I2 23 %, p = 0.26).
Conclusion: Platelet rich plasma injections appears to offer significantly better clinical outcomes, and raises no major safety concerns when used in the treatment of knee osteoarthritis for up to 12 months post treatment.
