Treatment of acute superficial flexor tendon injuries in performance horses with high molecular weight sodium hyaluronate

The purpose of this study was to evaluate the efficacy of high molecular weight (HMW) sodium hyaluronate (Hylartin V) for treatment of acute equine superficial flexor tendinitis. The study was a blinded randomized clinical study with placebo control. The horses included in the study were clinical patients diagnosed with tendinitis based on physical symptoms and ultrasonography, as well as historical information consistent with acute onset. Sixty-three horses were enrolled in the study, but ten were excluded from statistical analysis because they had tendon injuries in more than one leg (seven cases, four horses) or in a hind leg (three cases, three horses).Two (2) ml of sodium hyaluronate (treatment group) or 2 ml of saline (placebo) was given as a single injection into the center of the superficial flexor tendon lesion. All other treatments and exercise recommendations were the same in both groups. The end point of the study was resolution of the ultrasonographic lesion within a six-month period. The results showed that 60% of the horses in the Hylartin V treatment group had their lesions resolved in that time frame, while 24% of the placebo group showed a similar degree of improvement and resolution. It was concluded that the treatment with HMW sodium hyaluronate significantly improves the rate of ultrasonographic resolution as compared with placebo control.