Osteochondritis Dissecans (OCD)
Osteochondritis dissecans (OCD) is a condition that develops in joints, most often in children and adolescents. It occurs when a small segment of bone begins to separate from its surrounding region due to a lack of blood supply. As a result, the small piece of bone and the cartilage covering it begin to crack and loosen.
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Who does it affect?
OCD most often develops in children and adolescents.
In many cases of OCD in children, the affected bone and cartilage heal on their own, especially if a child is still growing. In grown children and young adults, OCD can have more severe effects. The OCD lesions have a greater chance of separating from the surrounding bone and cartilage, and can even detach and float around inside the joint. In these cases, surgery may be necessary.
Why does it happen?
It is not known exactly what causes the disruption to the blood supply and the resulting OCD. It is considererd to involve repetitive trauma or stresses to the bone over time.
Pain and swelling of a joint — often brought on by sports or physical activity — are the most common initial symptoms of OCD. Advanced cases of OCD may cause joint catching or locking.
After discussing your child's symptoms and medical history, a physical examination of the affected joint will be performed.
Other tests which may help your consultant confirm a diagnosis include:
- X-rays. These imaging tests provide detailed pictures of dense structures, like bone. An x-ray of the affected joint is essential for an initial OCD diagnosis, and to evaluate the size and location of the OCD lesion.
- Magnetic resonance imaging (MRI) and ultrasound. These studies can create better images of soft tissues like cartilage. An MRI can help evaluate the extent to which the overlying cartilage is affected.
Observation and Activity Changes
In most cases, OCD lesions in children and young teens will heal on their own, especially when the body still has a great deal of growing to do. Resting and avoiding vigorous sports until symptoms resolve will often relieve pain and swelling.
If symptoms do not subside after a reasonable amount of time, use of crutches might be recommended, or splinting or casting the affected arm, leg or other joint for a short period of time.
In general, most children start to feel better over a 2- to 4-month course of rest and nonsurgical treatment. They usually return to all activities as symptoms improve.
Surgery might be recommended if:
- Nonsurgical treatment fails to relieve pain and swelling
- The lesion is separated or detached from the surrounding bone and cartilage, moving around within the joint
- The lesion is very large (greater than 1 centimeter in diameter), especially in older teens
Surgery usually involves removing the loose fragment of cartilage and bone from the ankle joint and drilling small holes in the injured bone. When the fragment is removed, a defect shaped like a small crater is left in the talar dome. It is this area where the drill holes are made. The drill holes allow new blood vessels to grow into the defect and help to form scar tissue to fill the area. Eventually this new scar tissue smoothes out the defect and allows the ankle to move more easily.
There are different surgical techniques for treating OCD, depending upon the individual case:
- Drilling into the lesion to create pathways for new blood vessels to nourish the affected area. This will encourage healing of the surrounding bone.
- Holding the lesion in place with internal fixation (such as pins and screws).
- Replacing the damaged area with a new piece of bone and cartilage (called a graft). This can help regenerate healthy bone and cartilage in the area damaged by OCD.
In some cases the surgery may be done using an arthroscope. An arthroscope is a special miniature TV camera that is inserted into the joint through a very small incision. Special instruments are inserted into the ankle through other small incisions. By watching on the TV screen, the consultant removes the fragment and drills the defect.
The ankle is a small joint, so it is sometimes difficult to get the arthroscope into certain areas. If the defect is in an area of the ankle difficult to reach with the arthroscope, an open incision may be required. This incision is usually made in the front of the ankle to allow the consultant to see into the joint. Special instruments are used to remove the fragment and drill the injured area.
In general, crutches are required for about 6 weeks after surgical treatment, followed by a 2- to 4-month course of physical therapy to regain strength and motion in the affected joint.
A gradual return to sports may be possible after about 4 to 5 months.
Possibile complications will be discused with your consultnat prior to the surgery.
General risks include:
- Regional pain