Kienböck's disease is a rare condition affecting one of the small bones in the wrist called the lunate. The condition develops when the blood supply to the lunate becomes reduced, causing the bone to weaken, collapse and eventually lead to wrist arthritis if left untreated.
Mr Robert Farnell is an experienced specialist Consultant Orthopaedic Hand and Wrist Surgeon who has been working in Leeds for over 25 years. He exclusively treats conditions affecting the adult hand and wrist, including wrist arthritis, scaphoid non-union, complex wrist injuries and Kienböck's disease.
What is Kienböck's disease?
Kienböck's disease is a condition in which the lunate bone gradually loses its blood supply. This process is known as osteonecrosis or avascular necrosis.
Without an adequate blood supply, the bone becomes weaker over time and may eventually collapse. As the shape of the lunate changes, the smooth movement of the wrist becomes disrupted and arthritis may gradually develop.
Although trauma may bring attention to the wrist, it is not generally believed to be the direct cause of Kienböck's disease. The exact cause remains unknown.
Figure 1: The lunate is one of the eight small carpal bones in the wrist.
Who develops Kienböck's disease?
Kienböck's disease is uncommon. It most frequently affects adults between the ages of 20 and 40 and is seen more commonly in men than women.
Many patients have a wrist where the ulna is slightly shorter than the radius. This is known as ulnar negative variance and may increase the loading through the lunate bone. However, not everyone with this wrist shape develops Kienböck's disease.
Symptoms of Kienböck's disease
The symptoms usually develop gradually and can vary considerably between patients.
- Pain in the middle of the wrist
- Pain that becomes worse during activity
- Reduced grip strength
- Loss of wrist movement
- Mild swelling around the wrist
- Difficulty lifting or carrying objects
As the disease progresses and the lunate begins to collapse, the pain often becomes more persistent and everyday activities may become increasingly difficult.
How is Kienböck's disease diagnosed?
Diagnosis begins with a careful clinical examination and a discussion of your symptoms.
X-rays usually demonstrate characteristic changes once the disease has progressed. These may include:
- Increased density of the lunate bone (sclerosis)
- Collapse or flattening of the lunate
- Changes in the overall alignment of the wrist
- A relatively short ulna in some patients
MRI scan demonstrating early Kienböck's disease
Occasionally a CT scan is also performed to assess the amount of collapse and to help plan surgery.
Find out what to expect at your outpatient appointment.
Treatment for Kienböck's disease
Treatment depends on the stage of the disease, the amount of collapse present, whether arthritis has developed and your symptoms.
Non-surgical treatment
If symptoms are mild or the condition is diagnosed at a very early stage, treatment may include:
- Activity modification
- Pain relief medication
- A wrist splint or cast
- Regular clinical review
Although these treatments may help control symptoms, they do not restore the blood supply to the lunate.
Wrist-preserving surgery
If arthritis has not yet developed, surgery aims to preserve the wrist by improving the blood supply to the lunate and reducing the mechanical forces acting upon it.
One technique involves transferring a small blood vessel into the lunate. This is known as a vascularised bone graft or revascularisation procedure.
If the radius is relatively longer than the ulna, a radial shortening osteotomy may also be performed. This redistributes the forces passing through the wrist and reduces pressure on the lunate.
These procedures may be performed individually or together depending upon the individual patient's anatomy and stage of disease.
Surgery for advanced disease
If the lunate has already collapsed and wrist arthritis has developed, treatment is directed towards relieving pain and preserving as much wrist function as possible.
The exact operation depends upon the pattern of arthritis and will be discussed during your consultation.
Recovery after surgery
Recovery depends upon the procedure performed.
Following wrist-preserving surgery, the wrist is usually protected in a cast or splint before rehabilitation begins with specialist hand therapy.
Recovery of strength and movement continues over several months.
Read more about post-operative care.
Results of treatment
The outcome depends upon the stage at which the disease is diagnosed.
Early diagnosis offers the greatest opportunity to preserve the wrist joint before significant collapse or arthritis develops.
Once arthritis has become established, treatment is aimed at relieving pain, maintaining useful wrist movement and improving hand function rather than restoring a normal wrist.
Persistent wrist pain without a clear cause?
If you have ongoing wrist pain, reduced grip strength or have been told you may have Kienböck's disease, Mr Robert Farnell can assess your wrist and advise whether further investigation or specialist treatment may be appropriate.
Kienböck's Disease FAQs
What is Kienböck's disease?
Kienböck's disease is a condition in which the lunate bone loses its blood supply, becomes weaker and may eventually collapse.
Is Kienböck's disease rare?
Yes. Kienböck's disease is an uncommon condition and is a relatively rare cause of wrist pain.
What causes Kienböck's disease?
The exact cause remains unknown, although disruption of the blood supply to the lunate is responsible for the condition.
What are the symptoms?
Common symptoms include wrist pain, swelling, reduced grip strength, stiffness and reduced wrist movement.
Can X-rays miss Kienböck's disease?
Yes. Early in the disease, X-rays may appear normal. MRI scanning is often the most useful investigation during the early stages.
What is osteonecrosis?
Osteonecrosis means bone death caused by loss of blood supply.
What is a radial shortening osteotomy?
A radial shortening osteotomy is an operation that shortens the radius bone to reduce pressure passing through the lunate.
What is a vascularised bone graft?
A vascularised bone graft transfers living bone together with its blood supply to help restore circulation to the lunate.
Can Kienböck's disease cause arthritis?
Yes. Without treatment, collapse of the lunate may eventually lead to wrist arthritis.
Is early treatment important?
Yes. Earlier diagnosis provides the greatest opportunity to preserve the wrist before arthritis develops.