Kienbock’s disease is a relatively rare disorder that disrupts the blood supply to the lunate. The lunate is one of eight small carpal bones in your wrist. It’s at the middle of the base of your wrist and important for wrist movement.
In an early stage, Kienbock’s causes pain. As it progresses, the bone tissue can die and cause more pain, wrist immobility, and arthritis.
Kienbock’s disease usually affects only one wrist. Surgery and other treatments are used to relieve pain and preserve wrist function.
In the early stage of the disease, your wrist is painful. As the disease progresses, symptoms include:
- tenderness over the bone
- decreased hand grip
- difficulty turning the hand upward
- clicking sound when your wrist moves
Kienbock’s disease progresses through four stages. The rate of progression varies from case to case. A 2014 study suggested that the disease progresses substantially faster than previously described. The same study also concluded that degeneration of the lunate happens earlier on in the disease than previously assumed.
Your lunate isn’t getting proper blood flow, but the damage may not show up on an X-ray of the area. Your wrist may be painful and feel like it’s sprained.
The cutoff of blood to your lunate makes the bone harden. This is called sclerosis and can be seen on an X-ray. Your wrist may be swollen, tender, and painful.
Your lunate dies and breaks apart, shifting the position of your other wrist bones. Your wrist may be more painful, with limited motion and a weakened grip.
The bones surrounding the lunate deteriorate, which can lead to arthritis of the wrist. Without medical intervention, the disease can be debilitating in this stage.
The exact cause of Kienbock’s disease is unknown.
It’s often associated with an injury to your wrist, such as a fall, that affects blood supply to your lunate. It also is associated with repetitive micro-injuries to your wrist, such as from jackhammer use.
Risk factors are:
- Differences in the length and shape of your forearm bones, the radius, and the ulna. This can put more pressure on your lunate.
- Only one blood vessel supplying blood to your bone, instead of the usual two. This can affect blood supply to your bone.
- Other diseases, such as lupus, sickle cell anemia, cerebral palsy, and diseases that affect blood supply, are associated with Kienbock’s disease.
Kienbock’s disease occurs most commonly in men between 20 and 40 years old. You’re also at an increased risk if you regularly do heavy manual labor.
If you have persistent wrist pain, it’s important to see a doctor to find out the cause. Early diagnosis and treatment of Kienbock’s disease can lead to a better outcome.
In an early stage of the disease, you may be able to relieve pain with conservative treatment.
If Kienbock’s disease isn’t treated, your lunate bone will continue to deteriorate. This could lead to severe pain and loss of movement in your wrist.
Kienbock’s disease can be difficult to diagnose, especially in its early stages when it resembles a wrist sprain.
Your doctor will ask about your medical history, your lifestyle, and your wrist pain. They will physically examine your wrist and hand. Your doctor may also order an X-ray to further examine your wrist bones.
Sometimes early Kienbock’s doesn’t show up on an X-ray. Your doctor may order an MRI or a CT scan to examine the blood flow to your lunate.
Treatment for Kienbock’s disease depends on the severity of pain and the stage of lunate deterioration.
In an early stage of Kienbock’s disease, your doctor may prescribe anti-inflammatory drugs to relieve pain and swelling. Immobilization of your wrist may take pressure off the lunate and help restore the flow of blood to the bone. Your doctor may advise putting your wrist in a splint or cast for 2 or 3 weeks to keep it immobile.
Physical therapy can also help to improve the range of motion in your wrist. A physical therapist can assess your wrist and provide an exercise routine to help maintain your wrist use.
If you have more pain or the lunate is deteriorated, your doctor may advise surgery. There are several options available, depending on the degree of damage.
This involves grafting a piece of bone and blood vessels from another bone in your hand or arm to the lunate to restore blood flow. A piece of metal on your wrist (external fixator) may be used to keep the graft in place and relieve pressure on the lunate.
This procedure removes a piece of another wrist bone, the capitate, and fuses it with other segments of the same bone. It’s used in early stages of Kienbock’s disease, combined with revascularization.
This procedure is used to help stop the disease from progressing when your two forearm bones are not the same length. It may involve removing a section of the longer bone (usually the radius), or grafting a piece of bone onto the shorter bone (usually the ulna). This relieves pressure on the lunate.
Metaphyseal core decompression
This procedure levels your forearm bones by scraping the two bones involved without removing any bone tissue.
Proximal row carpectomy
This procedure removes the lunate bone if it has collapsed, along with two adjoining bones. This relieves pain, but leaves you with only partial wrist motion.
The lunate is fused to adjoining bones to create a solid bone. This procedure relieves pain and leaves you with partial wrist motion.
This would include a total wrist joint replacement. A resection arthroplasty in which the lunate is replaced with an artificial bone (made of silicon or pyrocarbon) has been done, but this procedure is used less frequently.
Recovery time from surgery can be up to four months. You may have to wear a cast to immobilize your wrist during healing. A physical therapist can help you maximize use of your wrist with proper movement and strengthening exercises.
There is no cure for Kienbock’s disease, but prompt treatment can help you preserve wrist function and relieve pain. The National Osteonecrosis Foundation and the Genetic and Rare Disease Information Center are resources you can check for research results and clinical trials.