Kienboeck's disease affects the lunate bone of the wrist.
There are several theories or mechanisms that try to explain the disease, but the cause remains unknown. Nobody really knows why this conditions affects certain people and not the others, and why it happens on one hand and not the other.
However, most doctors believe that the blood supply to the lunate is somehow disrupted, and then the lunate withers away. As a matter of fact, this disease is also known as avascular necrosis of the lunate - meaning "death of lunate for lack of blood supply".
Patients with Kienboeck's disease go to the doctor complaining of pain in the wrist, made worse by motion, made better by rest.
Xrays appear normal in early Kienboeck's disease. Often the patient is first told that he or she has a "wrist sprain."
These patients eventually end up getting an MRI when the pain does not get better. The MRI can make the diagnosis easily in the early stages of the disease.
The disease progresses over months and years.
In the later stages of the disease the lunate bone becomes sclerotic, crumbles, and the entire wrist may become arthritic and worn out.
- The carpus is the cluster of small bones of the wrist which connect the hand to the forearm.
- The lunate is one of the small bones of the wrist. Together with the scaphoid on one side, and the triquetrum on the other side, the lunate is part of the proximal row of the carpus.
In early stages, the treatment may involve immobilization with a brace or a cast, and avoidance of any strenuous activities involving the wrist. Such "rest" decreases symptoms, but doesn't cure this condition.
There are several surgical treatments for early Kienboeck's disease:
These operations do not appear to cure, or to significantly change the course of the disease. This is as of early 2013; for a quick reference, please see metaanalysis by Innes and Strauch, J Hand Surg 2010).
If you are a patient with Kienboeck's disease, you may still wish to try one these operations, but their effectiveness remains unproven, so beware.
You may ask, does the orthopedic surgeon have anything to offer for this condition?
The answer is yes: for more advanced disease, onf of the so-called "salvage operations" may offer relief: either arthrodesis (fusion of the bones of the wrist), or a proximal row carpectomy. I am partial to proximal row carpectomy.
Here's a sketch that explains the operation:
In the sketch of the left, the proximal row of the carpus is highlighted with orange color. The sketch on the right shows the left wrist after removal of the proximal row.
The patient is in his 50's with a history of years of wrist pain, which has become progressively worse. Xray shows clearly a sclerotic and collapsed lunate, compatible with stage 3 disease.
Here are xrays immediately after the surgery in the postoperative recovery room.
Here are xrays at 3 years after the surgery.
Despite progression of arthritis, pain was much better. Wrist motion is less than the normal unaffected right wrist, but better than the range of motion the patient had before surgery.