Kienböck’s disease, is a condition in which the lunate , one of the small bones in the wrist, loses its blood supply. This disease is most common between the ages of 20 and 40 and can affects both wrists.

Bone is a living tissue that requires a regular supply of blood for nourishment. If the blood supply stops, the bone, like all other tissues, can die (osteonecrosis) Kienböck’s disease develops gradually. At the beginning, restricted blood inflow causes only mild bone ischaemia, but as the disease progresses, lunate can die completely developing so called avascular necrosis (see Gallery below). Because lunate holds a central, pivotal position for biomechanics of the wrist, its degeneration can have a profound implications on long term function of this joint – pain, stiffness and in late stages, arthritis of the wrist.

The cause of Kienböck’s disease remains unknown. Ethiology is considered to be multi-factorial. Variations in several anatomical structures have been shown to be directly relevant. For example, variations in arteries, veins, bones like different shapes of the lunate itself and/or shorter length of the ulna, one of the two forearm bones. The disease is more common in patients with cerebral palsy and sickle cell anaemia.

Trauma either single or repeated episodes, has also been recognised as one of the precipitating factors, as injuries can disrupt the blood flow to the lunate. However, only small proportion of patients can recall trauma to the wrist in the past.

Many people just think they have sprained the wrist. At first, localisation of pain and symptoms can be vague, but stubborn, on-going discomfort eventually prompts a search for medical help. As the disease progresses, pain worsens and other symptoms become apparent: a reduced range of motion (stiffness), in particular, pain or difficulty in turning the hand upwards, wrist becomes progressively weaker with notably reduced grip strength. Pin-point tenderness is directly over the bone i.e. at the back and about the middle of the wrist. Occasionally there is a visible and/or palpable wrist swelling.

In its early stages, Kienböck’s disease may be difficult to diagnose because the symptoms are so similar to those of a sprained wrist. Patients often have the condition for months and years before they seek medical input. Slow progression of symptoms and signs make the clinical presentation more specific and easily elicits specialist’s suspicion of Kienbock’s. The crucial imaging for Kienbocks disease is magnetic resonance imaging (MRI).

The natural course of the disease as well as the results of its treatments varies considerably. Severity of the bone ischaemia and whether or not the disease progresses, seem to be the most important factors which ultimately determine the long term outcome. Although there is no cure, there are several options which can help patient’ symptoms. The disease process and response to treatment can take several months. On occasion, several forms of treatment, and even multiple operations, might be necessary.

Kienböck’s disease progresses through 4 stages. Treatment plan is usually based upon these stages.

Stage I: Symptoms are similar to those of a wrist sprain. X-rays are typically normal. Magnetic resonance imaging (MRI) is more likely to pick up abnormality, but can remain unremarkable. Sometimes, CT and bone scanning are necessary. Treatment: rest, splint, pain killers

Stage II: Wrist pain, swelling and tenderness. The lunate bone begins to harden and presents as whiter, denser on the x rays (it acquires ‘sclerotic’ appearance).
Treatment: rest, splint, early surgery

Stage III: Increasing pain, weakness in gripping and stiffness. The dead bone begins to collapse and break into pieces. As the bone begins to disintegrate, the surrounding bones may begin to shift and malrotate in abnormal position.
Treatment: rest, splint, steroid injections, surgery

Stage IV: Pain aggravated even by light activities; stiffness, swelling. There is a collapse of surrounding bones too and consequent wrist arthritis.
Treatment: steroid injections, surgery

The goals of all treatments are to relieve the pressure of the lunate and facilitate better perfusion around diseased bone. Such changes cannot erase the problem, but have shown to be able to halt and/or slow down disease progression in some patients.

It always helps to plan things in advance of surgery and adjust work and life activities accordingly. Therefore, please consider the following issues prior to your operation:

• Anticoagulation medication (Aspirin, Brufen, Warfarin, Clopidrogel) should ideally be stopped few days before the operation to reduce the risk of bleeding, but advise from the clinician who prescribed them is wise beforehand. I would strongly advise you to stop smoking prior to surgery as this can badly affect the outcome of surgery and increase complication rates.
• Please make sure that you arrange to be collected from the hospital as you will not be able to drive after the surgery
• Plan your time off school / work / sports
• Allow at least few weeks after surgery before considering holiday

Few surgical options are usually deserved for more advanced cases (Stage 3-4 fo the disease), and should be very carefully considered as it invariably involves complex interventions. The choice of procedure will depend on several factors, including disease progression, activity level, personal goals, and the surgeon’s preference, usually based on his/her personal experience. Evidence is still controversial as to whether any surgical intervention can actually favorably influence course of the disease. I have personally looked after quite a few patients who had been helped by surgery immensely so would offer the following few procedures to carefully selected patients:

Revascularisation

In small number of patients with early disease, it may be possible to revascularise lunate i.e enhance the blood inflow to the bone by using a bone graft with a blood vessel attached to it. This procedure only makes sense if performed early i.e. before lunate bone starts to ‘crumble’ and change its shape. Bone and its artery are harvested and mobilised from the lower portion of one of the forearm bones (radius) into the lunate itself. It is a day case procedure which requires wearing of splint for 2-3 weeks.

Joint leveling procedures

Kienbock disease is commonly associated with a slight discrepancy in length of two forearm bones (radius and ulna) which define the upper edge of the wrist joint (see Gallery below). In such cases, a joint leveling procedure may be recommended. Either one bone (ulna) can be made longer using bone graft or another one (radius) can be shortened by removing a section of the bone. Leveling procedures tend to reduce the forces that bear down and compress the lunate and generally result in increased blood flow to the area as the bone heal following ‘surgical insult’. Surgery is carried out on a day care basis and requires immobilisation for 6 weeks postopertively.

Salvage Surgery

If the lunate is severely collapsed or fragmented into pieces, it can be removed together with two bones on either side of the lunate. This procedure is known as the Proximal Row Carpectomy. Such radical undertaking is necessary in order to maintain wrist biomechanics and preserve motion. This procedure, called a proximal row carpectomy, will relieve pain while maintaining partial wrist motion.

Alternatives are joint fusions and joint replacements (prosthesis used). Fusion can be partial (when only few of the wrist bones are joined together) or total (when all of the wrist bones are connected together with a bone graft). The former preserves some wrist motion, the latter abolishes it completely. Each procedure has its benefits, indications and limitations which must be discussed on an individual basis.