Osteochondritis dissecans (OCD) is a condition that occurs when blood supply to the bone and cartilage in the ankle joint is cut off. Usually the condition develops as a result of some kind of trauma to the ankle. If left untreated, a fragment of bone can become detached inside the joint and cause chronic pain.

Though rare, osteochondritis is found mostly in young athletes, especially those involved in sports that require repetitive movement like jumping and pivoting.

Causes of osteochondritis

There are multiple factors that contribute to the development of osteochondritis. In most cases, the condition can be traced to a previous injury to the talus bone, which is usually caused by a sprained ankle.

Causes of osteochondritis dissecans can include:

• Ankle injury - A severe ankle sprain can fracture the talus bone in the ankle. If the fragment moves, it will cause pain and discomfort. Even a minor sprain can cause damage to the articular surface of the talus, reducing the bone's blood supply. 
• Loss of blood supply - Vascular insufficiency may also lead to osteochondritis. This eventually causes the death of bone tissue.

Osteochondritis symptoms

The progression of osteochondritis can be slow or rapid. The damaged bone and its cartilage may stay in place for some time, causing only minor discomfort. When a fragment of bone detaches, pain will worsen. It is important to see a physician if you feel your pain is progressing.

Symptoms of osteochondritis: 

• Ankle instability (or a feeling of your ankle joint giving way). 
• Ankle stiffness (especially after your ankle has been at rest). 
• Limited range of motion. 
• Pain (often triggered by physical activity). 
• Swelling of the ankle joint.

Treatment of osteochondritis

Osteochondritis treatment will depend on the extent of injury to the affected joint. If the damage is limited to bruising of the bone, resting the joint might be all that is required. In most cases, the initial damage to the talus bone is not recognized early; unfortunately, by the time the diagnosis is made a lesion has formed, or a fragment has detached from the bone.

Conservative Treatment

Most physicians will initially recommend conservative treatment to reduce pain, this may include: 

• A brace to immobilize the joint. 
• Anti-inflammatory medications. 
• Limiting physical activity (particularly sports). 
• Physical therapy. 
• Resting your ankle.

Surgery

If pain persists for more than three months; if motion of the ankle joint is restricted; and if conservative treatment has failed to reduce swelling, surgery is an option. The exact treatment will be tailored to your specific type of injury, but surgical options include the removal of loose bone fragments, reattachment of loose cartilage, and bone drilling (to promote blood flow). The goal of any surgical procedure on the joint will be to restore blood flow to the joint and improve mobility.