Osteochondritis Dissecans (OCD) of the Knee

What is osteochondritis dissecans?

The ends of the thigh bone and shin bone are covered with smooth joint cartilage, which is supported by a layer of bone just underneath. In osteochondritis dissecans, often shortened to OCD, a patch of that supporting bone becomes weak. The cartilage above it can crack, and in some cases the piece of bone and cartilage comes loose inside the knee.

It most often affects the inner part of the end of the thigh bone, but it can occur elsewhere in the knee, including the kneecap, and sometimes in both knees.

Symptoms, as parents and patients describe them

• "His knee aches during and after football, but he can't point to one spot"
• "Her knee swells after sport and is stiff the next day"
• A limp or walking with the foot turned outwards
• "Something gets stuck in my knee" or the knee suddenly locks, which can mean a loose fragment
• Pain with stairs, jumping or kneeling

Early on, symptoms are often vague, and the condition may be found on an X-ray taken for another reason.

Causes and who gets it

The exact cause is not fully understood. Repeated stress on the bone from sport, a reduced blood supply to a small area and genetic factors are all thought to play a part. It is seen most often in active children and teenagers, roughly between 10 and 20 years of age, especially those playing running and jumping sports such as football, basketball and athletics, and it is more common in boys. Adults can also have OCD, often from a lesion that did not heal in childhood.

Diagnosis

X-rays, including a special tunnel view of the knee, usually show the lesion and whether the growth plates are still open. An MRI scan is important because it shows the size of the lesion and, crucially, whether it is stable or whether fluid has tracked under it, which suggests it is loosening. It also shows the cartilage surface and any loose bodies. The other knee may be X-rayed too.

Treatment

The plan depends on age, whether the growth plates are open, and whether the lesion is stable.

Stable lesions in children with open growth plates often heal without surgery. Treatment involves stopping running and jumping sports, sometimes using crutches or a brace for a period, and repeating X-rays or MRI over around three to six months to confirm healing. This requires patience from both the child and the family.

Surgery is considered when the lesion is unstable, when it does not heal with rest, or in older teenagers and adults. Options include arthroscopic drilling to encourage blood flow and healing, fixation of the fragment back in place with small screws or pins, and removal of loose fragments. When the defect cannot be saved, cartilage restoration techniques may be used to rebuild the surface.

Recovery

With non-surgical care, a gradual return to sport is usually possible once imaging confirms healing, often after several months. After drilling or fixation, crutches are usually needed for around six weeks, followed by physiotherapy, with return to sport commonly at around four to six months. Cartilage restoration needs a longer, more structured recovery.

For children, the school and sports coaches can help by allowing alternative activities during recovery. Swimming and cycling may be introduced earlier than running when your surgeon agrees.

When to see a knee specialist in Doha

• Knee pain in a child or teenager that lasts more than a few weeks
• Swelling after sport, or pain that is not improving with rest
• The knee catches, locks or gives way
• A limp or reluctance to play
• An X-ray or MRI report mentions an osteochondral lesion

Early diagnosis gives a better chance of the lesion healing without surgery. Dr. Gelber assesses osteochondritis dissecans in children, teenagers and adults at Aman Hospital in Doha.