変形性膝関節症に対する多血小板血漿注射の現在の展望：臨床的転帰を最適化する方法

Knee osteoarthritis (OA) is a common degenerative joint disease affecting approximately 22% of adults over the age of 40 and is a major contributor to pain and disability worldwide. Platelet-rich plasma (PRP) has gained attention as a biologic treatment for this pathology due to its potential in modulating inflammation. This narrative review evaluates the current evidence on PRP for knee OA, comparing its efficacy to hyaluronic acid (HA), corticosteroids, and bone marrow aspirate concentrate (BMAC). High-quality studies consistently demonstrate that PRP provides superior pain relief and functional improvement compared to HA and corticosteroids and offers comparable results to BMAC. PRP is effective across all Kellgren-Lawrence grades, with the greatest benefits seen in early to moderate OA. Three-injection regimens appear more effective than single injections, and while both leukocyte-rich and leukocyte-poor formulations are used, no clear consensus exists on which is superior. Despite promising short- and mid-term outcomes, variability in preparation methods and limited long-term evidence remain important limitations. Current literature suggests that PRP may be a safe and potentially effective nonoperative option for managing knee osteoarthritis, though further high-quality, standardized studies are needed to confirm its long-term efficacy and optimal application.