Clinical outcomes of biologic therapies for knee osteoarthritis: A systematic review and meta-analysis of studies with ≥12-month follow-up

This systematic review and meta-analysis aimed to assess the clinical outcomes of biologic therapies, which include platelet-rich plasma and cell-based therapies (e.g., adipose-derived mesenchymal stem cells), on pain, physical function, and disease progression in patients with knee osteoarthritis (OA), focusing on studies with a follow-up of at least 12 months. We searched for randomized controlled trials (RCTs) posted at some stage in January 2000-May 2025. Eligible research protected the ones in adults with Kellgren-Lawrence grades I-III OA who underwent at least 12 months of follow-up. The bias risk was assessed, and the evidence certainty was evaluated. Random-effects models were used for pooled analyses. Fourteen RCTs were included. Compared with control treatments, biologic therapies significantly reduced pain and improved physical function. Potential structural benefits, including cartilage thickness preservation and favourable biochemical changes, were noted. However, substantial heterogeneity in study design and intervention protocols, along with potential publication bias, reduced the certainty of evidence to a very low level. Biologic therapies may be associated with improvements in pain and physical function at ≥12 months of follow-up, with preliminary indications of structural benefit. Nevertheless, high-quality multicenter RCTs with extended follow-up are warranted.