Kienbock’s disease is a disorder that affects your bone. For unknown reasons, the blood supply to the lunate, a bone in the wrist is deprived of blood. Without the blood providing nutrients to the bone cells, the bone tissue begins to die. The symptoms include pain in the wrist and loss of motion, so often patients think they’ve sprained their wrist but they can’t remember hurting it.
The author of this article reviewed the current concepts and thinking about Kienbock’s disease.
When trying to determine the cause of Kienbock’s, researchers have several theories, such as repetitive trauma to the wrist, the placement of the wrist bones, and even the size of the lunate. Certain illnesses, such as sickle cell disease, cerebral palsy, and septic emboli may increase the risk, as may the use of corticosteroids, but this hasn’t been proven.
When diagnosing Kienbock’s, doctors will look for certain issues, such as pain and weakness in the wrist but no recollection of trauma to the wrist or hand. The pain may be mild or it may be severe, it may be slowly progressing or it may be sudden. The pain is most often worse at the end of range of motion, especially as the wrist is being extended. Grip strength is also usually less than with the other, non-affected, hand.
X-rays of the wrist may or may not show something – it depends on how far the disease has progressed. There may be signs of collapse in the bone surface or a fracture of the lunate. Some physicians may order magnetic resonance imaging (MRIs) to have a better view of the wrist, especially if the x-rays aren’t showing anything unusual. The MRI can show if there is a loss of bone marrow fat and how dense the bone is.
Once Kienbock’s has been diagnosed, it must be staged. In other words, how bad is it?
Stage 1: Normal x-ray, intensity changes found on MRI
Stage 2: Sclerosing (thickening) of the lunate seen by x-ray, fracture lines may be seen
Stage 3: Lunate surface collapse
Stage 4: Lunate collapse and arthritis is present
Treatment for Kienbock’s is aimed at symptoms because there’s no cure for the disease itself. The goal of treatment would be to help limit the damage, improve usefulness of the wrist and limit pain. Treatment can be with surgery or without. Conservative, or nonsurgical, treatment means using a cast (for about three months). This is generally the treatment for Stage 1 of the disease. Unfortunately, studies show that most patients move on to stage 2 though.
Stages 2 and beyond usually require surgery. In stage 2, the surgeon will cut out the part of the bone that has died, thereby shortening the bone. Revascularization, or re-establishing the blood supply, has been tried with a few different procedures. These involve trying to adjust the load on the bones so there isn’t as much of stress on the bone or by redirecting blood supply. Other surgeries involve bone grafting, fusion or even surgery to affect the nerve. Bone grafts have seemed promising. In one study of 18 patients, 16 had successful grafts at five- and 10-year follow-ups.
Radial shortening, shortening of the bone is considered a simple surgery with good results, but at what stage it should be done isn’t always agreed upon. Joint leveling is another technique, but this isn’t always successful and there are reports that arthritis may be a complication from the surgery. A newer procedure for earlier stages is called core decompression, and this has had fairly good results so far.
In the last stage, stage 4, the surgeon may have to do a denervation, which means cutting the nerve so it no longer causes pain. This can be done alone or in combination with other procedures. While denervation does help some patients, it doesn’t help all, unfortunately.
The author concludes that treating Kienbock’s is still difficult since there are not obvious causes. Advancements in surgical procedures have been helpful in helping to relieve the symptoms and effects of the disorder and seem to have satisfactory outcomes for most patients.