Kienböck's Disease

What it is

Kienböck's disease is avascular necrosis of the lunate: the bone loses its blood supply and gradually dies. The lunate sits in the center of the wrist and is key to normal motion. It is most common in men between 20 and 40 and rarely affects both wrists.

What causes it

There is no single cause. Contributing factors include a short ulna relative to the radius, the shape of the lunate, one or more injuries, and conditions that affect blood supply, such as lupus and sickle cell disease.

Symptoms

• Wrist pain and swelling
• Tenderness over the center of the wrist
• Stiffness and decreased motion

Because it progresses slowly, many people have it for months or years before seeking care.

Diagnosis

History, examination, and X-rays. In early stages, X-rays can look normal, and an MRI is the most reliable way to assess the bone's blood supply. CT scans are also used.

Treatment

In early stages, observation, activity changes, or immobilization may be enough. More advanced stages usually call for surgery to reduce the load on the lunate or improve its blood supply. When the bone has collapsed or arthritis has set in, salvage procedures that remove the lunate and other wrist bones may be needed. Hand therapy helps preserve motion but does not change the course of the disease.