Intra-articular treatment with triamcinolone compared with triamcinolone with hyaluronate: A randomised open-label multicentre clinical trial in 80 lame horses

Summary Reasons for performing study Intra‐articular (IA) injection of corticosteroids with or without hyaluronate (HA) has been used for decades in equine practice for treatment of noninfectious synovitis and osteoarthritis. However, to date, no large‐scale randomised equine field trials have been reported that address the supposed superior clinical efficacy of the combination of corticosteroid + HA compared with IA injection of corticosteroid alone. Objectives To compare the clinical efficacy of IA triamcinolone acetonide (TA, 12 mg) compared with IA TA (12 mg) + high molecular weight HA (20 mg) in horses with clinical joint disease. Study design Prospective, randomised, parallel, open label, multicentre clinical trial. Methods Eighty client‐owned horses from 13 clinics were included. Lameness and effusion scores were assessed at baseline and 3 weeks after IA treatment. A standardised telephone questionnaire was completed between the owner and consulting veterinarian at 3 months. The primary outcome parameter was clinical success rate, defined as ≥2 grades lameness reduction (on a 0–5 scale) at 3 weeks. Chi‐square statistics and binary logistic regression were used to analyse data on an intention‐to‐treat basis for the 3 week outcome. Results The success rate of IA TA 3 weeks after treatment was 87.8%, while that of TA+HA was 64.1% (P = 0.01). Age >13 years was associated with a reduced success rate for the combination treatment (P = 0.004) at 3 weeks. At 3 months, half the horses in each group had returned to their previous level of performance. Conclusions The combination of TA with HA was associated with a lower short‐term clinical success rate and a similar medium‐term outcome compared with IA TA, with only half of the horses performing at their previous level of exercise after 3 months regardless of treatment group allocation.