Do radiographic signs of sesamoiditis in yearling Thoroughbreds predispose the development of suspensory ligament branch injury?

This research shows that yearling Thoroughbreds with more severe cases of sesamoiditis depicted on their yearling radiographs are more likely to develop a suspensory ligament branch injury (SLBI) in their initial year of race training.

Research Objective

• The objective of this study was two-fold: to determine the prevalence of SLBI within a population of juvenile training racehorses, and to explore the correlation between the clinical signs of SLBI and sesamoiditis. It aims to verify if sesamoiditis in yearling Thoroughbreds is a risk factor for suspensory branch injury.

Methodology

• The study is a retrospective case control one, where the presale radiographs of 291 clinically normal yearlings were reviewed for sesamoiditis and categorized on 3 different scales.
• The medical records for the first year of race training were assessed to identify cases of SLBI, and then compared to the unaffected controls from the same cohort.
• Statistical analysis was then used to establish the relationship between sesamoiditis and the development of SLBI in the course of training.

Results

• The study found that the prevalence of SLBI in the population group was approximately 10%.
• It was also found that horses which went on to develop SLBI had shown a higher severity of sesamoiditis in their yearling radiographs than the ones who remained unaffected.
• However, this significant correlation was only evident when one of the three grading scales was used. Based on that scale, Thoroughbreds with more serious sesamoiditis indications on their yearling radiographs were five times more likely to develop SLBI.

Conclusion

• The study concluded that the grading scale used to measure sesamoiditis severity is a crucial factor when providing prognosis to stakeholders such as veterinarians and horse owners about the significance of radiographic signs of sesamoiditis.
• More pronounced signs of sesamoiditis signify an increased risk (up to five times) of developing clinical SLBI once Thoroughbreds begin training. As a result, Thoroughbreds that display no clinical symptoms of the disease at sale could still be at risk.
• Considering these results, clinicians should be aware that Thoroughbreds displaying signs of sesamoiditis in their yearling radiographs may be at a greater risk of SLBI in the future, serving as a critical precursor for early prevention and management of the condition.