Background Platelet-rich plasma (PRP) is increasingly applied in knee osteoarthritis (KOA), but its long-term efficacy remains uncertain. This study assessed 5-year outcomes of intra-articular PRP compared with conventional therapy in early-stage KOA. Methods A retrospective cohort of 116 patients with bilateral KOA (Kellgren–Lawrence I–II) treated in 2019 was analyzed. Group A (n = 58) received standardized management plus three PRP injections, while Group B (n = 58) received standardized conservative management alone (NSAIDs and/or intra-articular hyaluronic acid), combined with education, exercise therapy, and weight management. Pain, function, and quality of life were evaluated by VAS, WOMAC, and SF-36 at baseline and 5 years. Results Both groups showed deterioration over 5 years. VAS increased from 4.64 ± 0.52 to 5.41 ± 1.17 in Group A and from 4.80 ± 0.59 to 5.44 ± 1.16 in Group B, without significant between-group difference ( P = 0.849). WOMAC and SF-36 scores also worsened similarly, with no intergroup significance ( P > 0.05). Intra-group analyses confirmed significant declines from baseline ( P < 0.001). Conclusions Although a short, single course of leukocyte-poor PRP did not yield sustained superiority over standardized conservative management at 5 years, this real-world study provides rare long-term comparative evidence that defines the temporal boundaries of PRP efficacy and underscores the need for maintenance or optimized dosing protocols in clinical practice.
Yu et al. (Thu,) studied this question.