Ask the Vet: Tendon & Ligament Injuries & Rehabilitation

Question: My 18-year-old horse tore 60% of his deep flexor tendon. We are five months into recovery. Will he ever be able to jump again or do these injuries have a tendency to tear again?

Answer: This is an excellent question and one I often get from my clients. Unfortunately, each case is individual and there is no way to predict which injuries will recur and which will not. It is widely accepted that stall rest, “active rest”, and a slow return to work are all very important in cases like this. The larger the lesion, the worse the prognosis is and the more likely the horse will re-injure the tendon when he resumes work. Front limb injuries have a better prognosis than hind limb injuries, but adding extracorporeal shock wave therapy during the rehabilitation period may improve the prognosis in hind limb injuries. Traditional support bandages like polo wraps don’t actually help support the tendons during exercise, but there are new support boots on the market that may in fact help support the tendons during and after the rehab period, which could help prevent re-injury. These cases can sometimes be “heartbreakers”, because it is possible to give the horse all the time he needs, bring him back to work very gradually, and still experience a re-injury, despite taking all possible precautions.

Question: With a suspensory injury, does the lesion ever fill in or look normal on ultrasound after rehabilitation? What are the chances of re-injury?

Answer: Both of these are excellent questions, and unfortunately both vary depending on the individual case. It is possible for a suspensory lesion to fill in, given enough time, but sometimes they persist on ultrasound even a year or more after the original injury. Certain therapies, such as the injection of PRP, can cause a lesion to fill in ultrasonographically, although the ligament may still not be as strong as it was prior to the injury. Sometimes the lesion may fill in with slightly different tissue fibers, which causes it to remain visible on ultrasound. In certain cases, the ligament may contain muscle fibers interspersed throughout the structure, which may make interpretation of the ultrasound difficult, both before and after injury and rest and rehab time. This is more commonly found in hind suspensory ligaments. The potential for re-injury depends on many factors, such as severity of the injury, therapies used during rehabilitation, length of time before return to full athletic function, and intensity of training.