Comparative efficacy of intra-articular hyaluronic acid and corticoid injections in osteoarthritis of the first carpometacarpal joint: results of a 6-month single-masked randomized study.

Objective: The study aim was to compare the efficacy and safety of ultrasound-guided intra-articular injections of hyaluronic acid and betamethasone in the management of patients with osteoarthritis of the thumb.

Methods: Eighty-eight evaluable patients diagnosed with osteoarthritis of the thumb (Kellgren-Lawrence grade II-III) received ultrasound-guided intra-articular treatment with hyaluronic acid (48) or betamethasone (40). In total, 3 local injections were scheduled at 7-day intervals. Assessments were performed at baseline and at 7, 14, 30, 90, and 180 days.

Results: In both study groups, the pain Visual Analogue Scale and Functional Index for Hand Osteoarthritis scores decreased significantly during follow-up compared to baseline. There were no significant differences between the groups. However, at 90 days, the functional score showed a trend towards greater clinical improvement in the hyaluronic acid group (P 0.071). A subanalysis of patients with Functional Index score≥5 and Visual Analogue Scale score≥3 at baseline showed a significantly higher median functionality score in the hyaluronic acid group (P 0.005 at 90 days and P 0.020 at 180 days). Further limiting analysis to a baseline pain score≥5 showed significantly greater improvement in functionality score (P 0.004 at 180 days), which was already apparent after the second intra-articular injection at 14 days (P 0.028). In this patient subset, the mean pain score also improved significantly at 180 days (P 0.02).

Conclusions: Both hyaluronic acid and betamethasone were effective and well-tolerated for the management of rhizarthrosis. Hyaluronic acid was more effective over time and more efficiently improved functionality and pain in patients with more severe symptoms.