Diagnostic imaging of tendinopathies of the superficial flexor tendon in horses.

The research article discusses the use of diagnostic imaging to identify and monitor the progress of tendon injuries in sport horses. With focus on the superficial digital flexor tendon (SDFT), the study explores the benefits of affordable and widely accessible grey scale ultrasonographic examinations.

Tendinopathies in Sport Horses

• The article reveals that tendinopathy of the superficial digital flexor tendon (SDFT) is a common ailment among all types of sport horses and especially, racing thoroughbreds.
• Often, swelling in the metacarpal or metatarsal area denotes the presence of a tendon injury. However, this manifestation is subjective and it’s difficult to predict the gravity of the injury based on clinical pictures alone.

Phases of Tendon Injury

• After an initial injury, a tendon injury typically progresses through four phases: reactive inflammation, fibroblastic proliferation, remodelling, and maturation.
• The dynamic nature of these overlapping phases of tendon injury can be monitored using grey scale ultrasonographic examinations. This diagnostic method is not only cost-effective but also widely available, with mobile equipment enabling onsite examinations in stables.

Reactive Inflammatory Phase

• In the reactive inflammatory phase, the injured tendon swells and a hypoechoic area of fiber disruption becomes evident on ultrasonographic images.
• As the hypoechoic area fills up with blood and debris, it appears as heterogeneous hypo- to hyperechoic areas in the ultrasonographic view. This disrupted area may be overlooked in transverse imaging, but can often be clearly identified in longitudinal images due to loss of fibre pattern.
• At this stage, an increase in the tendon’s cross-sectional area (CSA) is indicative of injury if it’s 20 percent more than the contralateral limb in unilateral cases.