What is it?
Kienböck's disease refers to the death of the lunate, one of the eight carpal bones that forms the wrist joint. The blood supply to the lunate is disrupted, leading to the death, fragmentation, and collapse of the bone. The cause of the blood supply disruption is a topic of some debate and there is no consensus opinion. Several factors have been associated with Kienböck's disease, including increased length and tilt of the distal radius relative to the ulna, blood-clotting abnormalities, and certain systemic diseases. None of them have been shown to be the single causative factor.
What are the symptoms?
Patients with Kienböck's disease typically complain of wrist pain localized centrally on the back of the wrist/hand. Pain intensity varies from mild to severe and increases with wrist motion and lifting. Depending on the severity of the disease, wrist motion may be decreased when compared to the uninvolved wrist.
How is it evaluated?
X-rays of the wrist will demonstrate sclerosis, fracture, and/or collapse of the lunate associated with Kienböck's disease. Both MRI and CT scans of the wrist can provide helpful information regarding the extent to which the lunate is diseased.
How is it treated?
Treatment of Kienböck's disease is guided by both the severity of symptoms and the radiographic appearance of the lunate and wrist. Surgery is often necessary, particularly in the more advanced cases.
The goal of treatment is to halt the progression of the disease by improving the blood supply to the lunate. This may be accomplished through several different procedures including decreasing the pressure on the lunate through a radial shortening osteotomy or removing a portion of the dead bone and replacing it with bone graft. If the lunate has completely collapsed with resultant severe wrist arthritis, excision of wrist bones or a wrist fusion may be necessary.