What Is Osteochondritis Dissecans?

Osteochondritis dissecans (OCD), also called an osteochondral lesion, refers to damage to the end of the bone that forms a joint. As the bone breaks down, so does the cartilage covering the bone. This can cause a piece of the bone or cartilage to partially or fully separate (Figure 1). Osteochondritis dissecans is a rare condition.

Osteochondritis dissecans of the knee is most common. There are also cases of osteochondritis dissecans of the elbow or ankle. Very few patients have osteochondritis dissecans in other joints. Usually, this condition affects one joint at a time.

Osteochondritis dissecans is most common in growing children, ages 8–16, who are very active in sports. It often starts as a mild, aching pain that can get worse over time. The pain may occur after an injury or trauma to a joint. Without treatment, osteochondritis dissecans can lead to further joint damage and early development of osteoarthritis.

Figure 1: An X-ray of a typical knee compared to a knee with osteochondritis dissecans.

Osteochondritis Dissecans Causes

Medical experts don’t know the specific cause of osteochondritis dissecans. Genetics may play a role. Some think that a lack of blood flow and oxygen to a joint leads to this condition. Others agree that repetitive stress to a joint (for example, repeated stress fractures) may result in osteochondritis dissecans.

Because the cause of osteochondritis dissecans isn’t known, there’s no clear way to prevent it. Only 15 to 29 people out of 100,000 get osteochondritis dissecans. The condition is most common in children and adolescents who play regular, highly competitive sports. It can affect adults if they had undiagnosed or untreated osteochondritis dissecans as a child.

Osteochondritis Dissecans Symptoms

The most common symptom of osteochondritis dissecans is long-term pain or swelling in the affected joint. With osteochondritis dissecans of the knee, children also may experience knee locking or a feeling of water on the knee (called effusion).

Osteochondritis Dissecans Diagnosis

Diagnosing osteochondritis dissecans can be challenging because it’s so rare. It may be confused with other conditions that usually improve on their own. Examples include Osgood-Schlatter disease, patellar tendonitis (jumper’s knee) and patellofemoral pain syndrome (runner’s knee).

With osteochondritis dissecans, patients usually have had joint pain for a long time. The only way to diagnose osteochondritis dissecans is with an X-ray. The X-ray provides a detailed image of the joint. Most doctors also order magnetic resonance imaging (MRI).

An MRI helps doctors diagnose one of four osteochondritis dissecans stages.

• Stage 1—The least advanced stage. Usually, the cartilage and bone have minimal damage and are still attached.
• Stage 2—The cartilage is cracked, and a piece of bone is partially detached.
• Stage 3—The cartilage is cracked, and a piece of bone is fully detached but hasn’t moved.
• Stage 4—The most advanced stage. The cartilage is cracked, and a piece of bone is completely detached and has moved.

Osteochondritis Dissecans Treatment

There are two main types of treatment: non-surgical treatment and surgery.

Physical Therapy

Most patients start with non-surgical treatment for osteochondritis dissecans. The first step is to rest the joint. Children must stop playing most sports for at least two to four months. During that time, they also may use crutches, a brace or a cast to reduce pressure and protect the joint.

Physical therapy for osteochondritis dissecans is also used as a non-surgical treatment. It’s important to start a physical therapy routine quickly after an injury. Physical therapy can address pain, range of motion and strength while protecting the joint as it heals. The goal of physical therapy is to get children back to their previous activities.

Surgery

A doctor may suggest surgery for osteochondritis dissecans if:

• Non-surgical treatment hasn’t relieved symptoms.
• The osteochondritis dissecans stage is more advanced.
• The patient is age 13 or older.

Most surgeries are outpatient procedures. This means children go home the same day. The surgeon may do one of the following:

• Perform an arthroscopic surgery, where they drill into the affected area. This surgery can help get more blood flow to the area and promote healing.
• Secure the loose bone in place with pins and screws.
• Use a bone graft to replace the damaged area. New bone or cartilage for the graft may come from the patient’s body or another source, such as a cadaver.

During recovery from osteochondritis dissecans surgery, most children are on crutches for at least six weeks. They also complete two to four months of physical therapy to rebuild strength in their joint.

Osteochondritis Dissecans Long-Term Outlook

Osteochondritis dissecans healing times vary by child. It usually takes at least four months to heal. About 90% of children are healed within a year.

During healing time, children should avoid activities that cause or increase pain. They shouldn’t run, jump or do high- impact activities until their doctor or physical therapist says it’s safe. Once osteochondritis dissecans heals, it’s unlikely to happen again or cause problems as an adult.