What Is Kienböck's Disease?

Kienböck's disease is a rare, debilitating bone disorder. It causes abnormalities in the lunate bone—one of the eight small carpal bones of the wrist. This condition is often the result of injury or inflammation of the wrist.

Recurrent pain and stiffness with thickening, swelling, and tenderness are common characteristics of this condition, eventually causing limited range of motion in the wrist. Kienböck's only affects one of the wrists.

Kienböck's disease is also known as avascular necrosis of the lunate or osteonecrosis of the lunate. This condition commonly affects people aged 20 to 40, most of whom are men.

Kienböck's Disease Symptoms

One of the first signs of Kienböck's disease is a painful wrist. As the disease progresses, a person will experience additional symptoms, including:

• Bone tenderness
• Stiffness
• Swelling
• Handgrip problems
• Problems with turning the hand upward
• Clicking sounds with moving the wrist

Stages

Kienböck's disease is known for progressing through four or five stages. The rate of progression varies from person to person.

The stages of Kienböck's disease are:

Stage 0: These early symptoms are similar to a wrist sprain and may include wrist swelling, pain, and tenderness. X-rays and magnetic resonance imaging (MRI) usually appear normal at this stage. 

Stage 1: In this early stage, the lunate loses blood supply. The bone will appear normal on regular X-rays, but changes may be seen on MRI scans. There may be pain and swelling, and the risk for fracture is increased.

Stage 2: In stage 2, an X-ray may show unusual bone density. This is because as the bone loses its blood supply, it will harden. On an X-ray, these hardened areas appear brighter and whiter than the surrounding bone. These changes are signs the bone is dying. MRI or computed tomography (CT) can help determine the condition of the bone. Symptoms of recurrent pain, swelling, and wrist tenderness are common at this stage.

Stage 3: In stage 3, the bone will start to break down into pieces. The surrounding bones may start to shift. Symptoms may include increased pain, weakness with gripping, and limited range of motion.

Stage 4: By this stage, the lunate has completely collapsed, and the nearby bones have become arthritic and damaged. In some people, Kienböck's disease will not advance to this stage.

Not every person with Kienböck's disease will experience all four stages. Some people may advance slowly through the stages, while others have disease changes that progress quickly.

One 2014 study suggests Kienböck's disease may progress faster through the stages than researchers have previously thought, and degeneration of the lunate may occur early. In this study, the researchers used high-resolution MRI and ultra-thin section CT to determine whether the patterns and extent of osteonecrosis (bone death) were consistent with the disease symptoms in all patients.

Among the 35 patients, 46% had signs of degeneration of lunate cartilage on CT scans in the first 12 months following the onset of symptoms. Some patients were experiencing median wrist pain in the first 12 months and experienced fracture. Another 31% had arthritis of lunate, but no fracture at the time of examination.

Causes

An exact cause of Kienböck’s disease is unknown. What is known is that the condition is associated with injuries to the wrist—such as a fall—that affect the blood supply to the lunate.

The condition is also associated with repetitive, small injures to the wrist, especially those related to certain occupations, such as with someone who uses a jackhammer on the job.

Some risk factors may contribute to the development of Kienböck’s disease. For example, most people have two vessels supplying blood to the lunate, but some people may only have one source, which may slow down the blood flow to the bone.

Additionally, if the two bones of the forearm—the radius and ulna­—are of different lengths, extra pressure causes wrist motions of the lunate to become more difficult, leading to Kienböck’s disease. 

Other risk factors for Kienböck’s are diseases that affect blood supply and conditions like lupus and sickle cell anemia. People who do regular heavy manual labor jobs also have an increased risk for Kienböck’s disease.

Diagnosis

Most people live with Kienböck’s disease for months and years and do not seek medical attention until symptoms become problematic. You should see your healthcare provider if you have ongoing wrist pain to determine the source of your pain. Early diagnosis and treatment can lead to better outcomes.

Your practitioner will ask about symptoms, medical history, including any previous traumas to the wrist, and how long you have had symptoms. The medical professional will also examine your hand and wrist. 

Imaging may or may not be helpful. This is because early on Kienböck’s disease doesn’t show up on X-rays. However, in the later disease stages, imaging can show changes to the wrist bones and lunate, including areas of hardening and breakage. An MRI or a CT scan can also examine the blood flow to the lunate.

Treatment

Treatment for Kienböck’s disease depends on the severity and disease stage. In early disease stages, treatment may include mobilization and pain management, including anti-inflammatory drug therapies, with a wait and see approach.

Physical therapy will not change the course of the disease. It can, however, help with relieving pain and restoring function to the wrist.

It is important to monitor changes in the early stages of Kienböck’s disease. If pain is not relieved with simple treatments or if the pain returns, your healthcare provider may recommend surgery.

Surgical Treatments

There are several surgical options for treating for Kienböck’s disease. The choice of procedure will depend on how far advanced the disease is. Additional factors your healthcare provider will consider are your personal goals, your activity level, and your surgeon’s expertise.

Your surgical options may include:

• Revascularization: This procedure, which involves surgically sliding blood vessels from another part of the wrist to over the lunate, is a common procedure done in early Kienböck’s disease.
• Joint leveling: If Kienböck’s disease is the result of uneven bones in the forearm, joint leveling might be an option. By shortening or lengthening the forearm, the surgeon helps to put the forearm bones at a healthy ratio to one another. Afterward, there is little pressure on the wrist, and disease progression stops.
• Lunate excision: This surgery removes the problem bone. To prevent slipping by the missing lunate bone, the surgeon will set an artificial bone in the place of the removed lunate.
• Intercarpal fusion: This surgical procedure is usually done in the late stages of the disease to join the lunate to the carpal bone. The procedure may be combined with a revascularization procedure.
• Proximal row carpectomy: In the fourth and final stage of Kienböck’s disease, the collapsed lunate bone starts causing arthritis throughout the wrist. With a proximal row carpectomy, the surgeon will remove four of the eight bones in the wrist joint, making room for the wrist to regain its stability. While this surgery can cause some wrist strength loss, it will still relieve wrist pain and maintaining a range of motion.

Recovery

After surgery for Kienböck’s disease, you will need to wear a splint for three to four months. Your surgeon will want to monitor you to see how your wrist bones are healing.

If the wrist heals well and you don’t need any adjustments, the next course of treatment is physical therapy three to four months. Physical therapy will help you to regain strength and motion in your wrist. Once you have pain relief from Kienböck’s disease, your life can go back to normal.

A Word From Verywell

There is no cure for Kienböck’s disease, but early diagnosis and prompt treatment can help with preserving function in the wrist and relieving pain. Your response to treatment will depend on the degree of damage in the lunate and its surrounding bone.

Some people with the condition may require more than one procedure if the disease continues to progress. But treatment will give you the best opportunity for preservation of your joint function and for offering long-term pain relief.