A systematic review of the effects of platelet rich plasma on outcomes for patients with knee osteoarthritis and following total knee arthroplasty.

Introduction: Platelet rich plasma (PRP) has been suggested to be effective in the management of knee osteoarthritis. Review of current literature reveals conflicting evidence regarding the benefits of PRP in treating knee OA. Preclinical evidence supports the use of PRP injections to promote a favorable environment for joint tissue healing, targeting not only cartilage but also synovial and meniscal tissues which has a positive effect on delaying the progression of OA. Growth factors found in platelet granules are postulated to influence outcomes in knee OA and after total knee arthroplasty (TKA).

Methodology: A systematic review of studies investigating the use of PRP in knee osteoarthritis and following TKA, was performed by searching the following databases for randomised clinical trials and pseudo-randomised clinical and comparative trials comparing the use of PRP to treat knee osteoarthritis and following TKA: MedLine, EMBASE, Science Direct, PubMed, and the Cochrane Library. The primary outcomes were patient reported measures including pain (visual analog scale (VAS)), quality of life scores, and knee function.

Results: A total of 2328 participants were analyzed across 17 included studies and pooled results showed a statistically significant reduction in pain in favor of PRP following TKA but not in non-surgical management of knee OA (P < 0.0001 and 0.13 respectively). No clinical benefit of PRP was found on quality of life and knee function (P = 0.07 and 0.05) following TKA, although a statistical improvement in knee function was demonstrated in patients with knee OA after PRP injection (P < 0.0001). There was no statistically significant clinical benefit of PRP on secondary outcomes including wound scores and length of hospital stay (p = 0.33 and 0.31, respectively). There was no statistically significant difference in respect to blood loss and overall symptoms in favor of PRP compared to control group following TKA (p = 0.37).

Conclusion: This systematic review demonstrated no long-term statistically significant improvement in patient validated outcomes and secondary outcomes both in patients with knee OA or following TKA for OA. However PRP has been shown to have short to medium-term benefits in pain control after TKA and activities of daily living in patients with OA.