Long-Term Follow-up of Superficial Digital Flexor Tendonitis Treated by a Single Intralesional Injection of a ReGeneraTing Agent in 51 Horses

ReGeneraTing Agents (RGTA) are nanopolysaccharides engineered to mimic heparan sulfates and have been shown to stimulate tissue repair and healing (skin, cornea, gingival, and muscle) in several animal models of injury and in human medicine. A preliminary study, monocentric and uncontrolled, was conducted to evaluate the efficacy of a dedicated RGTA (named Equitend) in improving the healing quality of the injured tendon after a single and ultrasound-guided intralesional injection. Improvement of ultrasonographic appearance of tendinous or ligamentous lesion was documented at least over 4 months in Equitend-treated horses and was further supported by another study on superficial digital flexor tendonitis, in 51 horses (16 French Standardbred trotters (ST), 13 Thoroughbreds (TB), and 22 eventers). Long-term follow-up of these horses showed high rates of return to racing, with 95% of eventers, 87.5% of French ST, and 77% of TB. The mean duration before the first race or competition was 6.6 and 7.4 months for ST and eventers, respectively. The group of 16 treated ST was then compared with a matched control group, showing that the Equitend-treated group was able to return to a higher level of earning after lesion (74% vs. 15% in the control group). Furthermore, the Equitend-treated group was back in racing 2.4 months earlier than the control group.     

Acellular Urinary Bladder Matrix in a Collagenase Model of Superficial Digital Flexor Tendonitis in Horses

The objective of the present study was to determine the efficacy of urinary bladder matrix (UBM) in collagenase-induced superficial digital flexor (SDF) tendonitis by using clinical, ultrasonographic, and histologic data. A total of eight healthy adult horses were used in this study. Bilateral forelimb SDF tendonitis was created in the horses by injecting collagenase. After 14 days, one randomly selected forelimb SDF tendon was blindly treated with UBM and the opposite tendon was treated with a control (saline). Clinical and ultrasonographic parameters including lameness, lesion size, ultrasonographic fiber pattern, and echogenicity were measured throughout the study. After 84 days, horses were euthanized and SDF tendon lesions from the two groups were compared statistically using an analysis of variance with significance set at P ≤ .05.Results showed that there were no significant differences between the treated and control tendons for any of the clinical, ultrasonographic, gross, or histologic variables. UBM does not appear to be an effective treatment for collagenase-induced SDF tendonitis. However, there may be differences in clinical tendonitis that might render the treatment more effective in the clinical setting.     

Evaluation of Return Rates to Races in Racehorses After Tendon Injuries: Lesion-Related Parameters

Metacarpal tendon diseases are important problems that may cause a decrease in performance and even may finish sport life in equine athletes. In this study, it was aimed to evaluate the ratio of return to races and the time of staying away from races and also to detect the prognostic value of ultrasonographic findings in Thoroughbred and Arabian racehorses with metacarpal flexor tendon injury or peritendonitis. Of 120 cases, 84 (70.0%) returned to races. Among these, 82.1% had tendonitis (69/84) and 17.9% peritendonitis (15/84). Among the cases being unable to return to races, 91.7% had tendonitis (33/36), and 8.3% had peritendonitis (3/36). Although not statistically significant (P > .05), tendonitis cases were found to be away from races for longer periods. Tendonitis cases (85.0%, 102/120) stayed away from races for an average of 39.9 months, whereas peritendonitis cases (15.0%, 18/120) stayed away from races for an average of 27.1 months. It was found that the ratio of return to races after injury was higher in cases without tendon thickening (86.7%, 26/30) than in cases with tendon thickening (64.4%, 58/90). The results of this study show that tendon injuries causing tendon thickening have a negative effect on the ratio of return to races (P < .05).