Abstract: Overstrain injuries to the superficial digital flexor tendon (SDFT) and suspensory ligament (SI) are among the most common musculoskeletal injuries which contribute to the considerable wastage of racing Thoroughbreds. Many epidemiological studies have demonstrated the prevalence of and risk factors for tendon injury when racing but have not included those injuries sustained during training. However, since tendon injury during training is seen commonly in clinical practice, it is appropriate to determine the overall prevalence of tendon injury sustained during both training and racing. Objective: To determine the prevalence of overstrain injury to the SDFT and SL during training and racing among Thoroughbred flat racehorses in Japan in 1999. Methods: A retrospective study was performed using a sample population of 10,262 Thoroughbred racehorses. The medical information database of Thoroughbred racehorses registered by the Japan Racing Association (JRA) in 1999 was analysed for SDFT and SL overstrain injury diagnosed by a veterinarian employed by JRA during training and racing. Jump racehorses were excluded from this study. Results: The prevalence of forelimb SDFT tendonitis and SL desmitis was 11.1% (1130 cases) and 3.61% (370 cases) of the population, respectively. In the hindlimb, there were 0.06% (6 cases) and 0.14% (14 cases), respectively. Risks of SDF tendonitis in the forelimb in 3-year-olds or older horses were significantly higher than in 2-year-olds. In contrast, the risk of SL desmitis in the forelimb at age 3 and 4 years was 2.23 and 2.11 times higher, respectively, than in 2-year-olds, but this increased to 5.07 times in those age > or = 5 years. Entire males were at greater risk in comparison to females and geldings. Conclusions: The results suggest that the prevalence of SDF tendonitis and SL desmitis in the forelimb was associated with the horse's age and sex. The prevalence of SL desmitis increased further with age compared with SDF tendonitis, possibly reflecting a more rapid accumulation of degeneration in this structure. Conclusions: The age-related risk demonstrated in this study provides further support that overstrain injuries are associated with accumulated degeneration. These data provide a valuable resource for further research into the aetiology of tendon injury in the racehorse.
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The research focuses on determining the prevalence of overstrain injuries to the superficial digital flexor tendon and suspensory ligament in Japanese Thoroughbred racehorses during training and racing activities in the year 1999.
Research Methodology
The researchers conducted a retrospective study on a population sample of 10,262 Thoroughbred racehorses.
The medical information used was obtained from a database of Thoroughbred racehorses registered under the Japan Racing Association (JRA) in 1999.
The database was analyzed for diagnosis of overstrain injury to the superficial digital flexor tendon (SDFT) and suspensory ligament (SL) made by a veterinarian working for the JRA.
Jump racehorses were not included in the study.
Research Findings
The prevalence of forelimb SDFT tendonitis and SL desmitis were 11.1% (1130 cases) and 3.61% (370 cases) of the population, respectively.
In the hindlimb, the rates were significantly lower, with 0.06% (6 cases) for SDFT tendonitis and 0.14% (14 cases) for SL desmitis.
Risks of SDFT tendonitis in the forelimb in horses aged three years or older were significantly higher than those in two-year-old horses.
The risk of SL desmitis in the forelimb at age 3 and 4 was around double that in two-year-olds, increasing to over five times in horses aged five years or older.
Entire males were at a higher risk compared to females and geldings.
Research Conclusions
The results indicate that the prevalence of SDFT tendonitis and SL desmitis in the forelimb is associated with the horse’s age and sex.
The prevalence of SL desmitis increased with age compared to SDFT tendonitis, possibly indicating a more rapid accumulation of degeneration in the suspensory ligament.
The age-related risk established in this study shows that overstrain injuries are connected with accumulated degeneration.
The data obtained through this research provides a valuable resource for further investigation into the root causes of tendon injury in racehorses.
Cite This Article
APA
Kasashima Y, Takahashi T, Smith RK, Goodship AE, Kuwano A, Ueno T, Hirano S.
(2004).
Prevalence of superficial digital flexor tendonitis and suspensory desmitis in Japanese Thoroughbred flat racehorses in 1999.
Equine Vet J, 36(4), 346-350.
https://doi.org/10.2746/0425164044890580
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