Kienböck's disease is the loss of blood flow to the lunate bone in the wrist, so that over time it can no longer nourish itself and collapses; the medical name is avascular necrosis. It is seen most often in men aged 20 to 40 who use their hands heavily, and usually on the dominant side. We encounter it more often in people whose ulna is shorter than the radius in the forearm (negative ulnar variance), because more load passes onto the lunate.
The symptoms are insidious: pain over the upper-middle part of the wrist that grows over time, restricted movement, and reduced grip strength. Many patients mistake it for a sprain and arrive months late.
Early on, the X-ray often looks normal, so when I suspect it, I ask for an MRI. An MRI shows the blood-supply problem in the bone even when the X-ray shows nothing. Seeing which stage the disease has reached directly guides treatment.
Treatment depends on the stage of the disease; there is no single method that fits everyone. In the early stage, resting the wrist in a splint may be enough for a while. In later stages, to shift load away from the lunate, we use procedures such as shortening the radius bone, vascularized grafts that bring fresh blood to the bone, or fusing certain small joints. The goal is to reduce pain and stop the wrist from collapsing.