Kienböck’s disease (also termed avascular necrosis of the lunate) represents impairment of the lunate bone’s blood supply (avascular means absent blood supply and necrosis means death of the bone). The lunate is one of the eight small bones of the wrist and is situated near its centre. Bones are living structures that require a blood supply to maintain their nutrition and structural integrity. With progressive bone cell death, the lunate can break up (fracture and collapse) causing localised pain, swelling and stiffness. 

In advanced cases of Kienböck’s disease, the altered shape of the lunate can cause wear and tear (osteoarthritis) of the neighbouring bones and joint surfaces. Kienböck’s disease does not always progress to lunate fragmentation and osteoarthritis and the condition can sometimes reverse or stabilise with time. The cause and natural history of Kienböck’s disease (i.e. how it may progress with time) is poorly understood.

The cause of Kienböck’s disease remains poorly understood. The condition's relative rarity contributes to our poor understanding. Risk factors for developing Kienböck’s disease can be divided into those related to anatomy (such as the shape of the lunate) and those unrelated to anatomy (such as smoking); however, many risk factors remain controversial and the cause will remain unknown for the great majority of people.

Anatomical risk factors may include: (1) forearm bone length discrepancy (a relatively ‘long’ or prominent radius is a risk factor), (2) certain lunate shapes, and (3) the pattern of lunate blood supply. Although lunate shape and bone alignment can be assessed on wrist X-rays, there is no easy way to assess the pattern of lunate blood supply. Anatomical risk factors are thought to increase the pressure within the lunate and therefore reduce its blood supply. 

Risk factors unrelated to anatomy are varied and may include: smoking, diabetes, alcohol excess, previous wrist injury (or repetitive wrist strain or trauma) and some systemic disorders (such as lupus or sickle cell disease). Cerebral palsy with wrist involvement is also a risk factor.

The natural history of Kienböck’s disease (i.e. how it may progress with time) remains poorly understood. For example, we do not know why the disease progresses in some people but stabilises or even reverses in others.

There is a wide spectrum of severity for Kienböck’s disease and it is not possible to predict the natural history when patients present with early or mild changes of the lunate. Some people will have normal X-rays and the disease will only be identified on MRI scanning (this is termed grade 1 Kienböck’s disease). Mild Kienböck’s disease (grade 2) comprises subtle X-rays changes but with preservation of the lunate’s shape. Moderate or severe Kienböck’s disease includes loss of lunate shape or fracture and fragmentation that is sometimes associated with changes in the position of neighbouring wrist bones like the scaphoid (grade 3). Advanced Kienböck’s disease (grade 4) includes grade 3 changes plus wear and tear (osteoarthritis) of neighbouring joint surfaces. In some people the lunate will progress through all four stages and in others the disease will stop and not progress. Disease progression is often slow, usually taking years rather than months. description

Some of the potential symptoms of Kienböck’s disease are listed below. Many people with Kienböck’s disease will have no or minimal symptoms (the condition is sometimes identified coincidentally on scans for other problems).

Typically present:

• Pain that is dull and central in the wrist (palm side also common).

• Tenderness (around the central wrist).

Sometimes present:

• Weakness of grip (usually due to pain).

• Swelling (around the central wrist).

• Pain that worsens with activity, such as gripping and lifting.

• Stiffness with reduced wrist movements.

• Grinding or scratching feelings at the site of pain.

It is important to correctly diagnose Kienböck’s disease and exclude other causes of central wrist pain, such as wrist arthritis, distal radioulnar joint (DRUJ) arthritis, ganglion cysts, tendon inflammation (tendonitis), ulnocarpal abutment syndrome, triangular fibrocartilage complex (TFCC) tears or carpal tunnel syndrome. 

The diagnosis is usually made on the history (your symptoms), clinical examination and X-rays or a MRI scan. Sometimes a CT scan or wrist arthroscopy (‘keyhole’ surgical assessment) is recommended.

In most cases, the treatment for Kienböck’s disease is non-surgical, and most people will never require surgery for this condition. Stopping smoking, when applicable, may help to prevent the progression of Kienböck’s disease.

• Non-surgical treatment options include simple painkillers, avoidance of painful activities, wrist splintage or cast immobilisation (for many months) and hand therapy (mostly functional advice and splintage). It may take weeks or months to notice a gradual improvement and return to function. A steroid injection (e.g. cortisone) is occasionally used to help reduce pain associated with Kienböck’s disease; however, the pain-relieving effect will differ between individuals and will usually wear off with time (a good and common response would be 3-6 months of improved pain).

• Surgical treatment options include wrist arthroscopy (‘keyhole’ surgery), denervation, core decompression, joint levelling procedures (e.g distal radius osteotomy) and direct revascularisation (e.g. with bone graft), proximal row carpectomy (PRC), partial wrist fusions (e.g. scaphocapitate fusion) and total wrist fusion. Joint replacement may be suitable for a very small minority. Keyhole surgical assessment (arthroscopy) is sometimes helpful when assessing the extent of joint damage, for example when X-rays or scans are unclear. 

There are many surgical treatments described for Kienböck’s disease and decision-making is based on a combination of your symptoms, the severity and pattern of lunate disease and whether or not there is associated osteoarthritis. Unfortunately there is no strong evidence that any of the many treatments or operations designed to treat early or moderate Kienböck’s disease will halt progression or change the natural history.

Matthew offers all the above treatments. Matthew does not perform wrist replacement in the private sector.

Surgery for Kienböck’s disease is usually performed under general or regional anaesthesia. Click here for an overview of the different types of anaesthesia and the general risks of hand surgery.

The specific risks associated with surgery for Kienböck’s disease will be discussed if surgery is an option, but includes continuing pain, new pain and stiffness.

You can read more detailed information about Kienböck's disease on the Lothian Hand Unit website.