Osteochondral lesions of the Talus (OLT) are a condition that results from a loss of blood supply to an area of bone beneath the surface of a joint. It is usually due to an acute trauma, such as an ankle sprain, however chronic repetitive micro trauma may also be a cause. The affected bone and its covering of cartilage may stay in place and may not cause any symptoms, or a fragment may gradually loosen and cause pain.
Most people diagnosed with OLTs are young adults. OLTs are more common in males. Although it is rare, it's becoming more common, particularly among girls and young women as their participation in youth and college sports increases. Early diagnosis and treatment are important to minimize your risk of long-term disability. Some people with osteochondritis dissecans eventually develop osteoarthritis. When the disorder is treated promptly, most people recover and return to their usual activities, including participation in sports.
Pain is the most common symptom of OLT. The pain tends to be sharp or aching, and is usually triggered by physical activity — for example, knee pain that occurs while walking up stairs, climbing a hill or playing sports. Other signs and symptoms include:
- A clicking sound when you move your anklet
- A "locking" of your anklet — the joint "sticks" and won't move through its full range of motion
- A feeling that your ankle is "giving way" or weakening
- Decreased joint movement
- Swelling and tenderness of around the ankle
- Stiffness after resting
- An ankle sprain that ‘won’t get better’
Acute trauma is the main cause of OLT. Also high on the list is repetitive force (trauma or stress) to the ankle. You may experience small, multiple episodes of minor unrecognized injury that over time, can cause a tiny fracture that damages the overlying cartilage of a joint.
An impaired blood supply to the bone (vascular insufficiency) also may play a role in the condition. The impaired supply is due to a slight blockage of a small artery and gradually can cause a breaking down or death of bone tissue (avascular necrosis).
The diagnosis of OLT is made by thorough medical history and a standard orthopedic examination will involve checking the stability of the joint and whether there is a clicking or locking when you move the joint. X-rays of your joint from various angles could show abnormalities in the surface of your joint. However other imaging techniques are often needed to make the diagnosis:
- Computerized tomography (CT) provides computer-enhanced images of the joint structures. It can also detect any bone and cartilage fragments and pinpoint their location, including whether they have settled in the joint space.
- Magnetic resonance imaging (MRI) uses magnetic fields to create detailed pictures of your joint, which will provide information about its structure, the accumulation of fluid in the area and the visualization of loose fragments. Doctors frequently use MRI to help decide whether healing will occur with conservative treatment or whether surgery is necessary.
Treatment of OLTs is intended to restore the normal functioning of the affected joint and to relieve pain, as well as reduce the risk of osteoarthritis. No single treatment, however, is effective for everybody.
Treatment also depends on the chronicity of the injury as well as the age and physical condition of the patient. Non-operative measures include:
- Immobilizing your joint - This may involve using a hinged brace or crutches if your knee or ankle is affected.
- Using non-steroidal anti-inflammatory medications - These include aspirin, ibuprofen and naproxen.
- Avoiding competitive sports and intense physical activity - These may put a strain on your affected joint and cause pain. At least six to eight weeks of limited activity are helpful for most people.
When surgery is an option
When non-operative treatment fails, or the patient is not an appropriate candidate for conservative treatment, surgery is indicated and can usually be done through ankle arthroscopy. This involves inserting a thin scope into the joint space to visualize the area on a television monitor, determine the location of the damage and decide upon the best type of surgical procedure.
Then tiny surgical instruments are inserted into small incisions, and loose bone fragments may be reattached or removed. When cartilage fragments are still attached to the bone, they can be tightly secured with pins or screws.
Sometimes the size of the OLT is quite large, and a more invasive procedure is required. This usually involves cutting the ankle bone to gain access to the talus, ‘coring out’ the OLT, and replacing the bone and cartilage with tissue from the patient (autograft) or a cadaver (allograft). Both types of graft have their advantages and disadvantages.
Rehabilitation usually involves a period of immobilization and non-weight bearing followed by progressive weight bearing and motion. Typically patients fully recover by 4 to 6 months.