Evaluation of an intra-articular carboxymethylcellulose crosslinked hydrogel in horses with osteoarthritis

Background: Numerous treatment strategies have been proposed to manage osteoarthritis (OA) in sport horses. Carboxymethylcellulose (CMC), is used in veterinary medicine for various purposes. Aims/objectives: This study aimed to assess the efficacy of a CMC hydrogel in reducing clinical lameness in horses with OA affecting joint. The hypothesis was that intra-articular CMC would produce a sustained reduction in lameness compared to a control treatment. Methods: Thirty client-owned horses diagnosed with OA-related lameness in the metacarpophalangeal joint were enrolled. Horses were randomly assigned to two groups: the treated group (n = 16) received a single intra-articular injection of CMC hydrogel (3 ml/joint); the control group (n = 14) received 12 mg/joint of triamcinolone acetonide (TA) and 20 mg/joint of hyaluronic acid (HA). Lameness was evaluated at baseline and at 15, 30, and 90 days using a standardized AAEP scoring system. Treatment success was defined as a reduction of at least one lameness grade without additional therapy. Statistical analysis included the Kruskal–Wallis test and Chi-Square test; significance was set at P < 0.05. Results: At 90 days, 12/16 horses (75%) in the treated group achieved success (mean score 1.3 ± 0.6), compared to 1/14 horses (7.1%) in the control group (mean reduction 0.2 ± 0.4; P = 0.001). At 15 days, 3/15 CMC horses (20%) improved vs. 13/14 controls (90%). At 30 days, success was 75% in both groups. Conclusion: Intra-articular administration of CMC hydrogel provided a delayed but longer-lasting improvement in lameness compared to corticosteroid and HA treatment.