What do we know these days about osteochondritis dissecans of the elbow in young athletes? What causes this condition? Can it be cured? These are some of the questions answered in this review article written by sports medicine orthopedic surgeons from Rush University in Chicago, Illinois.
Osteochondritis dissecans (OCD) is a problem encountered most often by male adolescents (teens) involved in repetitive overhead throwing activities. Young girls participating in gymnastics are the second group affected most often. Gymnasts can spend quite a bit of time engaged in activities that require repeated weight-bearing on the arms leading to OCD.
What is OCD and what causes it? In this condition, repetitive microtrauma from repeated motions of the elbow causes the articular cartilage that lines the elbow joint to separate and break into pieces. When the cartilage pulls away from the joint, it takes a layer of subchondral bone with it. Subchondral just means “under the cartilage,” which describes the first layer of bone next to the articular cartilage.
Any bone within the elbow can be affected. But the most commonly involved bone is the capitellum. Here’s a quick review of elbow anatomy to help you picture the capitellum. The elbow is the connection of the humerus (upper arm bone) and the two bones of the forearm (the ulna and the radius).
The joint where the humerus meets the radius is called the humeroradial joint. This joint is formed by a knob and a shallow cup. The knob on the end of the humerus is called the capitellum. The capitellum fits into the cup-shaped end of the radius, also called the head of the radius.
When the head of the radius spins on the capitellum, the forearm rotates so that the palm faces up toward the ceiling (supination) or down toward the floor (pronation). The joint also hinges as the elbow bends and straightens.
When making the diagnosis, the orthopedic surgeon must distinguish between OCD and another problem called Panner disease. Although these two conditions are considered separate problems, some experts view them as two stages of the same thing.
Both affect the capitellum but Panner disease causes fragmentation of the entire capitellum. OCD is usually more of an isolated lesion that breaks away from the main bone causing a loose body to float inside the joint.
Panner disease tends to develop in young boys between the ages of 5 and 10 who aren’t involved in repetitive motions that cause trauma to the joint. For unknown reasons, normal growth in the outer edge of the elbow is disrupted, which causes the small area of bone to flatten out.
Symptoms of diffuse elbow pain are common with both Panner disease and OCD. Diffuse means throughout the entire elbow. Pain can occur along the outside or lateral aspect of the elbow. The pain is present with activity and there’s a loss of extension. The child cannot straighten the elbow all the way. There may be stiffness, swelling, and when there is a loose body associated with OCD, clicking, catching, and/or locking of the elbow can occur.
How does the physician tell the difference between OCD and Panner disease? The child’s age and activity level help sort this out. X-rays, MRIs, and the most definitive method: arthroscopy shows the type, location, and severity of cartilage and subchondral damage. MRIs are especially good at showing early changes when X-rays appear otherwise normal.
Once the diagnosis has been made, then a plan of care is developed. One main difference between Panner disease and OCD is that Panner disease is self-limiting. That means it will go away with rest and doesn’t require additional treatment. Over a period of one to two years, the bone slowly rebuilds itself. During this time, symptoms gradually disappear, although the elbow may never fully straighten out.
OCD may respond to rest, which removes the compressive load and shear forces long enough to allow healing. The use of antiinflammatory medications and a physical therapy program of stretching and strengthening exercises are also recommended.
OCD does not always improve with conservative care. With more advanced (more severe, unstable) lesions, surgery might be needed to help the cartilage heal. There are many different surgical procedures that have been used to help aid healing in OCD. These include drilling, grafting, chondrocyte implantation, and osteotomy.
Surgery is necessary when there are loose fragments of cartilage and subchondral bone floating inside the joint. Various techniques are described to reconnect the loose fragment (e.g., wiring, screw fixation, stapling). Sometimes the fragment just has to be removed.
Studies of the various surgical treatments have resulted in a wide range of results. There isn’t one technique that works the best for everyone. The surgeon must decide what might work best given the location and severity of the defect. Sometimes there’s more than one lesion to be considered.
To help surgeons who are treating OCD surgically, the authors provide many color photographs taken with an arthroscope of various cases they have treated. They describe the technique used to insert the scope into the joint to get the best possible view of what’s going on inside there. Different sized scopes can be used depending on the size of the child’s elbow.
Their preferred treatment is removal of small fragments and fixation of large loose pieces. Special surgical tools are used to shave any uneven edges of cartilage and create a healthy, smooth rim of cartilage. Whenever possible, osteochondral reconstruction is avoided if other less involved surgery can be done to aid in the healing process.
Most young athletes can expect to return to the sports activity of their choice. But there’s an extended period of time of physical therapy, rehab, and recovery. When full, pain free elbow motion is possible, then strengthening begins and progresses to include sports-specific training.
The prognosis for osteochondritis dissecans of the capitellum is not always good. Studies show that at least half of the children affected by this condition end up with arthritis and continued elbow pain, stiffness, and limitations. The prognosis seems poorest for those patients with the most severe, unstable lesions. New treatment techniques are undergoing study with hope for more promising long-term results.