Joint Injections Compared Joint injections using corticosteroids, hyaluronic acid (HA) or a combination of the two are commonly used to treat synovitis and arthritis in performance horses. In this study, researchers compared the efficacy of one type of corticosteroid (triamcinolone acetate, TA) with and without HA for the treatment of lameness, localized to one limb only that responded to a diagnostic joint block. Eighty horses of various breeds were enrolled in the study with follow-up at 3 weeks by re-examining the horses and 3 months by an owner questionnaire. No other medications were permitted during the first 3 weeks of follow-up.