Origin and Efficacy of Hyaluronan Injections in Knee Osteoarthritis: Randomized, Double-Blind Trial.

BACKGROUND Several hyaluronan preparations are available that have different dosage forms, origins, and concentrations. The objective of the study was to compare the efficacy of intra-articular chemically cross-linked hyaluronan (CCH) and avian-derived hyaluronan (ADH) injections in knee osteoarthritis (KOA) patients. MATERIAL AND METHODS In total, 258 patients were randomized into 2 groups of 129 each: patients who received CCH injection (CCH group) and patients who received ADH injection (ADH group). Radiographic Kellgren-Lawrence score, visual analog scale (VAS) pain score, Lequesne index score, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, single-limb stance (SLS) test, and timed "Up-and-Go" (TUG) test were performed. The Mann-Whitney U test or independent t-test following Bonferroni adjustment was performed for statistical analysis at 95% of confidence level. RESULTS The CCH group had improved VAS pain score (P<0.0001, q=54.803), total WOMAC score (P<0.0001, q=4.753), Lequesne index score (P<0.0001, q=3.208), and SLS time (P<0.0001, q=8.76) at the end of 6 months as compared to those in the ADH group. After 6 months of follow-up, the ADH group had improved TUG time (P=0.0148, q=3.385) as compared to baseline. Both groups of patients had the similar improvement in Kellgren-Lawrence score and mild to moderate adverse effects after 6 months. CONCLUSIONS CCH injection was superior to ADH injection.