The suspensory ligament is a structure that begins just below the knee and hock on the back of the horse's legs and extends downward to the fetlock. The particular injury I am going to talk about today is inflammation of the suspensory ligament just below the hock in the rear legs. This ligament is positioned between the bones and soft tissues and there is really no ability for the ligament to expand so inflammation causes pain because it cannot expand and can compress the surrounding nerves causing pain. Dr. Sue Dyson indicates in the Equine Veterinarian that horses with a damaged ligament in this area may be very lame or may just perform poorly.
Diagnosis of the condition is aided by ultrasound and looking at the fibers of the ligament compared to the normal ligament on the other leg. Also, a nerve block of the area is usually required to prove the lameness is due to pain in this area and in some cases even an MRI is required for diagnosis.
As far as treatment, rest alone is not a successful therapy as only 14% of these horses were able to return to work for at least one year. Shock wave therapy was effective in about 40% of the cases. One of the newest therapies is surgery to cut the nerve to the area of the injury (called neurectomy) and then opening the tissue to decrease pressure on the ligament, which is called a fasciotomy. Results of a study that consisted of 92 horses with only suspensory ligament disease that were treated with neurectomy and fasciotomy indicated 78% of them returned to the same level of work they were at before the injury for at least one year. Suspensory ligament disease is difficult to successfully treat and surgery seems to be the best option.