The Use of Intra-Articular Hydrogel in Knee Osteoarthritis: A Systematic Review

BackgroundKnee osteoarthritis (KOA) is a prevalent cause of disability. Current intra-articular injections (hyaluronic acid [HA] and corticosteroids) fall short in maintaining long-term effects and repeated usage may result in deleterious effects on the knee. The development of hydrogels offers a potentially safe and longer-lasting alternative.PurposeTo assess current literature and analyse the clinical outcomes of intra-articular hydrogel in patients with KOA.MethodsA systematic search on 4 databases was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta‑Analyses. Quantitative findings were complemented by narrative synthesis. Study quality was assessed using the Cochrane Risk of Bias (RoB) 2.0 tool and Methodological Index for Non-Randomized Studies guidelines.ResultsTwelve studies comprising 1,413 patients were included. Most reported improvements in clinical outcomes above the minimal clinically important difference. Average follow-up was 11 months. Quality assessment revealed high risk of bias for randomized controlled trials (RCTs) (n = 4) and low to moderate risk of bias non-randomized studies (n = 8).ConclusionIntra-articular hydrogel injections for KOA represent an area of ongoing investigation. Current literature is heterogeneous and limited by methodological shortcomings. Adequately powered RCTs with standardized outcome reporting are needed to clarify their role in routine clinical practice.Level of evidence:Level II.