Intra-Articular Viscosupplementation for Patients with Hip Osteoarthritis: A Meta-Analysis and Systematic Review.

BACKGROUND The aim of this study was to review the efficacy and safety of intra-articular (IA) viscosupplementation (VS) for hip osteoarthritis (OA). MATERIAL AND METHODS We searched Medline, Clinical Trial Register Center, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) comparing VS with placebo injection for hip OA. We included suitable studies, assessed the quality of studies, and extracted data on pain reduction, function improvement at different time points, and safety profiles. The comparisons of pain and function outcome were performed by meta-analysis. RESULTS Five high-quality randomized controlled studies trials (RCTs) with 591 patients with hip OA were identified. Although several trials demonstrated a significant decline in pain in VS groups during follow-up compared to baseline, without severe adverse events, the pooled analysis did not show VS was superior to placebo at any time windows [7-14 days: standardized mean difference (SMD): -0.18; 95% CI, -0.47 to 0.10, p=0.21; 28-30 days: 0.02 (-0.15, 0.19), p=0.82; or at final visit: -0.14 (-0.46, 0.18), p=0.38]. Similar results were also observed in the combined data of functional results. CONCLUSIONS IA VS does not reduce pain or improve function significantly better than placebo in a short-term follow-up. The benefits and safety of VS should be further assessed by sufficiently-sized, methodologically sound studies with validated assessment of more clinically relevant end-points.