According to Psyknowhow, the lunate malacia (synonyms: moon leg death, lunate necrosis or Kienböck’s disease ) is a disease of a carpal bone in which the lunate bone (os lunatum) dies off (necrotized) in whole or in part. The disease can reach different degrees of severity, which have different symptoms.
What is lunate malacia?
In the case of lunate malacia (the doctor also speaks of lunar bone death or Kienböck’s disease), the small bone trabeculae in the lunar bone progressively decay due to reduced blood flow. The human hand consists of eight carpal bones. The moon bone (Os lunatum) is one of the most important carpal bones and is located in the middle of the carpus. The bone trabeculae die off partially or even completely. Lunatummalacia most commonly occurs between the ages of 20 and 40. Men are twice as likely to suffer from lunar limb death as women.
The causes of lunate malacia have not been determined with certainty; doctors tend to suspect them to this day. The disease has been known for over 100 years. Even then, the doctor Kienböck suspected that an increasing circulatory disorder is the cause of lunate malacia. These circulatory disorders can have different reasons.
On the one hand, the lack of blood circulation can be predisposed. Accidents and a fracture of the lunar bone can also lead to reduced blood flow and thus to lunate malacia. Another possibility is permanent pressure or incorrect loading of the lunar bone (this can happen, for example, if you use a jackhammer frequently). There are also people who have a shortened ulna in relation to the radius (ulna and radius are the two forearm bones). This “disproportion” can result in reduced blood flow to the lunar bone.
Symptoms, Ailments & Signs
Lunatum malacia is manifested by severe hand pain. This is accompanied by a loss of strength in the affected hand. The patient can only tense his hand with difficulty, a fist and gripping movements are no longer possible. The movement restrictions can spread to the wrist. In individual cases, parts of the forearm are also affected.
The intensity of the symptoms depends on the stage of the disease. In the first stage, slight pain and restrictions in freedom of movement develop, which are not yet perceived as a problem by those affected. Only in the second stage do the symptoms intensify and there is persistent pain.
Visible swelling usually occurs due to edema forming under the skin. In stage III a, the decay of the bone is already well advanced. The patient can no longer stretch his hand fully and usually has chronic pain in the hand and wrist area.
In stage III b, a so-called carpal collapse occurs, which becomes noticeable through signs of paralysis. In the fourth stage, the deformity of the hand is complete and it is no longer possible to move the hand without pain. Symptoms develop over the course of months or even years.
Diagnosis & History
An x-ray is used to make the diagnosis. However, a normal X-ray cannot detect lunate malacia in its early stages. Only later stages show up on the X-ray image. This is why the disease is often not recognized until late. Other diagnostic options are nuclear spin and computed tomography.
The doctor will of course also perform a physical examination. The patient complains of wrist pain and subjectively believes that the wrist is swelling. Pressure on the lunar bone causes severe pain in that area.
In terms of differential diagnosis, the doctor can differentiate between lunate malacia and tendonitis based on the localization of the pain. With lunar bone death, the strongest pain is localized directly over the lunar bone, with tendonitis, the pain spreads equally to different parts of the hand or arm. Supporting the hand also leads to severe pain over the lunar bone.
If the disease is more advanced, the pain spreads over the entire wrist, there is swelling in the hand and the movement of the hand is restricted.
The doctor divides lunate malacia into four different stages, depending on how badly the lunar bone is damaged. If the disease is very advanced, deformities of the adjacent carpal bones also occur.
First and foremost, lunate malacia leads to relatively severe pain in the hand. This pain can also spread to the fingers or the backs of the hands and cause discomfort there. It is not uncommon for the pain to also occur at night and can lead to sleep disorders and thus to depression or irritability in the patient.
Furthermore, the muscles of the affected hand are severely weakened and the patient’s resilience is significantly reduced. Even the hand itself can no longer be moved easily, which means that there are various limitations in the patient’s everyday life. In many cases, the development of children is also affected by lunate malacia. Swelling or bruising also occurs.
In most cases, lunate malacia can be treated well without causing various complications. The patient’s life expectancy is also not reduced with this disease. It is not uncommon for a surgical intervention to be necessary, which, however, is also not associated with complications. However, those affected also depend on various therapies to restore the movement of the hand.
When should you go to the doctor?
Discomfort or pain in the hand should be presented to a doctor. If you lose your usual resilience or feel weak in your hands and arms, you should see a doctor. Restrictions in the range of motion of the wrist should be examined by a doctor. If everyday tasks can no longer be fulfilled or if the person concerned is no longer able to carry out usual sporting activities, a doctor is needed. Problems gripping or holding on to objects are warning signals from the organism.
If even simple activities such as opening a door can no longer be carried out, the person concerned must consult a doctor. Circulatory disorders, problems with perception in the hand or discoloration of the skin must be examined and treated. If you experience tingling, numbness or sensory disturbances in your hand, you should see a doctor.
If the symptoms occur repeatedly or increase in intensity, a doctor’s visit is advisable. If problem areas on the hand continue to spread, a doctor should also be consulted immediately. If there is swelling, edema or other deformities of the hand, a doctor’s visit is necessary. If signs of paralysis occur, medical help is required.
Treatment & Therapy
The treatment of lunate malacia depends on the stage present. First of all, the doctor tries to stop the disease as early as possible, i.e. to prevent the disease from progressing. As long as the final stage has not yet been reached, the chances are good.
In the two initial stages, a joint reflection is the method of choice. This allows the doctor to accurately assess the affected joints and hand bones. A histological examination is also part of the joint reflection. The tissue removal itself also relieves the bone. He can build himself up again because he now has more space available.
In the case of a very severe clinical picture, the doctor removes bone material from the patient’s pelvis in order to refill the affected carpal bone. If a shortened ulna is the cause of the disease, an operation is also necessary in which the doctor either lengthens the ulna or shortens the radius.
Another possibility is that the doctor interrupts certain nerve fibers in order to prevent pain transmission through these nerves. If the doctor cannot stop the disease despite all measures, a partial fusion of three carpal bones or even a fusion of the entire wrist may be necessary.
In addition to the surgical procedure, the patient needs a forearm cast and, depending on the type of operation, physiotherapy.
Outlook & Forecast
Lunatum malacia is a progressive disease. Therefore, the earliest possible treatment is crucial for the further course of development. In the early stages of bone disease, the prognosis is good. In a joint reflection and tissue removal, the bones can be relieved. The organism then regenerates itself to such an extent that full recovery can be achieved.
In an advanced stage of the disease, the treatment measures are more complex. A surgical procedure is necessary in which bone is removed from the pelvis and inserted into the wrist. The operation involves risks and is significantly more complex. The probability of complications or secondary disorders is increased with this procedure. To relieve the pain, the doctor can achieve changes through therapy of the nerves. This approach is also risky. There is the possibility of damaging surrounding nerve fibers and thereby triggering subsequent problems.
If left untreated, the symptoms will steadily increase. Physical performance in the hand decreases, making it more difficult to perform everyday duties. In addition to an early diagnosis, physiotherapeutic treatment is advisable for a good prognosis. The exercises learned there can also be used by the patient outside of the therapy sessions. This improves well-being and strengthens the organism.
Prevention is only possible to the extent that overloading and incorrect straining of the wrist is avoided. If there is a congenital circulatory disorder or if the patient has a congenital shortening of the ulna, prevention is not possible.
Regular follow-up checks should be carried out by the doctor treating you. This includes regular ultrasound examinations of the vessels in order to detect further progression of the circulatory disorders in good time. Treatment could then be used promptly if necessary and possibly prevent a worse course.
If an impairment due to the circulatory disorder persists, the rehabilitation measures that have been started should also be continued at home. When coping with everyday life, the relatives must also learn to cope with the new situation together with those affected. More exercise is one way to speed up recovery. Thus, the blood circulation is promoted in a natural way. In general, aftercare serves to alleviate the existing symptoms, which, depending on their severity, require individual attention.
You can do that yourself
If lunate malacia has occurred, further incorrect strain or strain on the wrist in general must continue to be avoided. This can prevent further damage. As a rule, early diagnosis and treatment have a positive effect on the further course of the disease.
The possibilities for self-help are severely limited with this disease, whereby those affected are usually always dependent on a surgical intervention. Without this intervention, the symptoms cannot be alleviated. Patients are often dependent on movement therapy or physiotherapy after the operation in order to restore the movement of the hand. The exercises performed can often be performed at home, which can speed up healing. However, the hand should always be spared and not unnecessarily strained.
Contact with other people affected by the disease can often have a positive effect on the course of lunate malacia. This can lead to an exchange of information, which can make everyday life easier. Since many of those affected are restricted in their everyday life by the pain, help from relatives or friends also has a positive effect on the course of the disease.