Ligament Injuries

Ligaments are the strong fibers that connect bone to bone. Some also provide joint stability. Any inflammation of the ligaments is referred to as desmitis, which occurs most often when a horse routinely takes a long stride. The most common injuries to the ligaments in the leg are desmitis of the suspensory ligament and inferior check ligament desmitis.

Graphic example of suspensory ligament.Desmitis of the Suspensory Ligament

The suspensory ligament is between the second and fourth metacarpals on the rear side of the third metacarpal (see graphic). Inflammation, or desmitis, is due to the stress on the ligament during a routine long stride (as with racehorses). Swelling in the middle to lower metacarpal is typical, although accompanied only by a mild lameness. In chronic cases, the ligament is enlarged and scar tissue can be palpated.

Treatment for Desmitis of the Suspensory Ligament

Systemic anti-inflammatories coupled with rest and physical therapy are necessary for treating desmitis of the suspensory ligament in horses. In acute cases, warm moist heat should be alternated with ice/cold therapy. Topical anti-inflammatories such as DMSO or capsaicin are helpful in reducing swelling to the area. In cases caused by a fracture to the lower portion of the second metacarpal, the fragment should be surgically removed; if not the fragment can cause a callus that will further irritate the ligament. Once the swelling has been reduced and all inflammation is gone, the horse can gradually return to training.

Inferior Check Ligament Desmitis

Graphic example of Inferior Check Ligament.The inferior check ligament in horses blends with the deep digital flexor tendon midway down the metacarpus and is often overlooked as a cause of lameness. Horses shod with a long toe have a longer stride and a low heel, which results in an unbalanced foot causing increased strain on the inferior check ligament. The horse experiences pain and lameness in the affected leg, but without swelling to the area. This lameness is often intensified when the horse is worked on a hard uneven track.

Inflammation of the inferior check ligament can either be acute or chronic. Diagnosis is made through ultrasound, infrared thermography and/or radiography. Injection of a local anesthetic to temporarily alleviate lameness helps to rule out injury to the deep digital flexor tendon.

Treatment for Inferior Check Ligament Desmitis

If detected early, treatment of acute inferior check ligament desmitis is very successful. Topical application of DMSO and/or capsaicin with physical therapy will lead to a rapid recovery. Physical therapy should include ice/cold therapy, massage and stretching, pressure bandaging, and systemic anti-inflammatories. To ensure a complete recovery, the horse should be rested for sixty to ninety days.

If the condition is chronic, the long toe should be removed and physical therapy started immediately. Physical therapy for chronic desmitis includes alternating warm moist heat with cold therapy, therapeutic ultrasound, low level light therapy, systemic anti-inflammatories and passive exercise with massage and stretching. Training is to be discontinued and the horse rested until complete recovery.