Description

Ringbone is a condition where new bone growth leads to a swelling that occurs on the horse's legs as a result of stress. The condition presents as a heated swelling which is sensitive to pressure either near the pastern joint or just above the coronary band.

Excessive tension on the tendons, ligaments, and joint capsules of the pastern area causes strain on the periostum. When tissues are stretched or torn and the joint is affected by the injury, the horse's system compensates by growing bone at the point of stress to help stabilize the joint.

Several factors contribute to ringbone: conformational defects, traumatic injuries, developmental factors.

Osteoarthritis of the pastern or coffin joint occurs when the horse's system produces bone growth in an attempt to immobilize the joint and relieve chronic inflammation of the joint capsule.

Ringbone usually occurs in the front legs and is most often found in mature horses that are engaged in intensive training.

Symptoms

• Lameness
• Pain in the affected area
• Decrease in performance
• Swelling of the pastern
• Warmth in the affected area

Causes

The development of osteoarthritis in the pastern and/or coffin joints is usually traumatic to the soft tissue surrounding the joint. This creates pain, inflammation, edema, fibrosis of the joint capsule, and new bone formation at the joint capsule.

These events reduce the already limited range of motion within the joint, and the weight-bearing forces create compression on areas of cartilage and bone in the joint. Ringbone is a progressive, degenerative condition, unless caused by direct trauma, and prognosis is best if the condition is diagnosed and treated early in the development of the condition.

Prevention

Preventing ringbone includes good horse management to prevent trauma to the pastern and coffin joints. Proper trimming of the hooves and shoeing appropriate to the demands made on the horse will help prevent ringbone especially when the horse is engaged in activities with repeated concussion that is absorbed by the pastern area.

Treatment

Radiographs are usually necessary for a definitive diagnosis of ringbone and can help determine the extent of the bone growth.

Non-steroidal anti-inflammatory drugs help alleviate the pain and reduce inflammation within and around the joints. In some cases, a veterinarian may inject the pastern joint directly with a form of corticosteroid and hyaluronic acid.

Rest, leg wraps, and hot and cold therapy are appropriate in some cases. Shockwave therapy may be used to modify the new bone growth and decrease pain. Appropriate shoeing with a roller motion shoe that facilitates an easier break over the foot by a knowledgeable farrier often helps with management of the condition.

Medical management may help extend the athletic career of horses, but usually does not result in long term soundness. Surgical treatment to fuse the pastern joint is sometimes useful, but surgery sometimes causes further bone growth.

A veterinarian with experience in orthopedic treatment and surgery should be able to suggest the best method for to prevent further injury or bone growth and to correct problems with the pastern and/or coffin joint.