Dr Steve Carter
Kienbock's disease is avascular necrosis of the lunate bone. This means loss of blood supply to the lunate, one of the very important carpal bones of the wrist. Kienbock's disease results in initially pain in the wrist, subsequent stiffness and ultimately arthritis of the wrist. In our experience in Cape Town, males and females are equally affected, usually the dominant wrist and normally between the ages of 20-40. It is an unusual case of wrist pain.
Often the cause is multifactorial which could include:
- Abnormalities in the blood supply of the lunate.
- Skeletal abnormalities, very often these patients have a shorter ulna bone which results in increased force across the lunate
- Trauma, single episode or repetitive.
Very often the exact cause cannot be elucidated.
Signs & Sympthoms
Most patients present with longstanding wrist pain. Very often they have been seen by numerous doctors. They also complain of stiffness in the wrist and difficulties with daily living or difficulties with job related activities. The diagnosis is made by physical examination and special investigation. Plain film x-ray may show changes in the lunate in later stages of the disease, but may be normal initially.
The progression of the disease varies and there are various stages used to classify the severity of the avascular necrosis. We use the Stahl and Lichtman classification which helps in directing the treatment program.
- Stage 1: The lunate has lost its blood supply, the wrist is painful but the x-ray is normal. This is where a MRI is required.
- Stage 2: We now see changes in the lunate, on x-ray it becomes sclerotic, that is when we see an increased density or whiteness on x-ray.
- Stage 3: Due to the collapse and subsequent dissociative pattern, the wrist starts to generate and develop radiocarpal osteoarthritis.
Treatment is directed at the appropriate stage. Initially mobilization, intra-articular cortisone may be required. We do not do revascularization procedures in order to improve the blood supply as we feel the results do not warrant the treatment. In later stages of the disease, if conservative methods do not control the pain, we attempt to alter the force on the lunate by shortening the radius of the ulna negative wrist. It may well be in Stage 3, to attempt to prevent further collapse, a limited wrist fusion may be performed. If generalised osteoarthritis develops, a full wrist fusion may be required.
In summary Kienbock's disease is a rare cause of wrist pain. Longstanding treatment will be required with a combination of various conservative and possible surgical modalities.