Kids play sports at an intensity not common in earlier generations. And with a year-round sports schedule, they’re developing a type of knee injury that used to be relegated to adults.

eochondritis dissecans (OCD occurs when an area of bone in the joint is damaged, disrupting the blood supply to the region. The affected area of bone dies. Sometimes the bone fragment remains in the place. In other cases, it can break free and “float” inside the knee joint. OCD is most commonly seen in the knee, but can occur in the elbow, hip or ankle.

In the initial stages, OCD can cause intense pain that increases with activity, swelling and a clicking or popping sensation when bending the knee. The athlete may be unable to fully straighten the knee or bend it through a full range of motion. The knee may feel stiff after rest.

OCD appears to be more common in sports using certain types of high-impact actions (like jumping, cutting or pivoting). Researchers believe repetitive minor trauma to the knee causes the damage that leads to OCD.

Shannon Safier, M.D., Pediatric Orthopaedist with St. Christopher’s Hospital for Children in Philadelphia, says many students are playing sports year-round. So their joints don’t get a rest and risk for OCD may increase. Safier says if the bone injury is detected early on (before the blood supply is cut off), conservative treatment is often effective. Patients are advised to rest and immobilize the joint, take non-steroidal anti-inflammatory medications and avoid playing sports for at least six to eight weeks, to give time for the injured bone to heal. Physical therapy may also be recommended to maintain/improve range of motion in the joint.

If the blood supply is cut off, but the bone and cartilage are still intact, doctors may be able to drill holes in the lesion. The body responds to this intentional injury by growing new blood vessel, restoring the blood supply to the affected area. If the area of bone dies, the affected area can no longer heal on its own. So the only option is surgery.

In many cases the surgery can be done arthroscopically, using small incisions and tiny surgical instruments. Safier explains the piece of bone is placed back into position and then secured with bioabsorbable screws.