Kienbocks

Kienböcks

There are two rows of small bones that make up the wrist joint. The lunate bone lies centrally in the first row. Kienböck’s Disease is a condition in which the lunate bone loses its blood supply. It is also known as osteonecrosis or avascular necrosis of the lunate. In the long term it can lead to arthritis at the wrist. There is no single identifiable cause of Kienböck’s disease but there are several suggested theories and associations. These include skeletal variations in forearm bone length, type of lunate blood supply, trauma, and underlying disease such as sickle cell anaemia and lupus. 

Symptoms relate to pain and stiffness whilst attempting to move the wrist, initially patients often feel they have sprained their wrist. When examined, tenderness is noted over the lunate bone, often with some wrist swelling, the patient can also complain of decreased grip strength. 

Kienböck’s disease is divided into 4 main stages. Patients may experience a variable progression through the stages, but in most cases the progression is slow.

• Stage 1 - there is mild to moderate pain and x-rays are usually normal but may indicate a fracture in the lunate.
• Stage 2 - the pain worsens and swelling may be noticeable. The lunate appears white (sclerotic) on x-rays.
•  Stage 3 - movement at the wrist becomes increasingly difficult, due to stiffness and pain, some patients lose grip strength. The lunate is now collapsing and breaking into smaller fragments
• Stage 4 - there is increased pain, stiffness and swelling to the wrist joint due to the degeneration of the bone surfaces adjacent to the lunate. X-rays demonstrate surrounding osteoarthritis

Treating Kienböcks

Following a history and examination of the affected hand and wrist, x-rays of the wrist will be taken. Should the diagnosis remain in doubt or further information is needed an MRI scan can help. Treatment is decided on an individual case-by-case basis after consideration of the patient’s symptoms, background and the stage of the disease. In the early stages simple painkillers such as paracetamol and anti-inflammatory medications may help relieve the pain and swelling. Splinting the wrist and avoidance of certain activities can reduce the amount of stress placed on the lunate. If symptoms fail to improve or worsen then surgical treatment may be considered.

The aims of surgical treatment are to either improve blood supply or relieve pressure to the lunate. There are a number of surgical options, which will be considered on an individual basis.

• Shortening one of the bones in the forearm can reduce the pressure applied to the lunate.
• Surgical revascularisation involves the placement of a bone graft, with its attached blood supply, in to the lunate bone. The bone graft may be taken from the forearm or wrist. This technique is most suitable for patients with early stage disease.
• Proximal row carpectomy is performed in cases where the lunate has disintegrated. The lunate and its surrounding bones are removed. Following the procedure there is still some wrist movement possible.
• Joint fusion (wrist arthrodesis) involves uniting some of the wrist bones to make one solid bone. Wrist flexion and extension will be sacrificed at the expense reducing pain. This procedure is performed on severe cases of Kienböck’s 

After surgery

You will to re-visit the clinic 1 to 2 weeks after surgery to check on recovery and we may take some  X-rays to monitor the healing process. Working with our Physiotherapist you will work on some specific exercises to regain normal wrist movements (dependent on surgery performed). A splint should be worn for 4 -6 weeks after surgery.

When I can return to normal activity (work, driving, sports)?

Whilst the bone is healing you will be wearing a cast or splint for up to 6 weeks so you will need to avoid any heavy lifting, manual work or sports to protect your recovery.