Kienbock's disease (lunatomalacia) is a condition that usually develops as a result of repetitive injury to the wrist, which leads to osteonecrosis, damage, and death of the lunate bone due to the loss of its blood supply.
Patients suffering from Kienbock's disease usually present with pain in the wrist joint, accompanied by other symptoms including swelling around the wrist joint, and deterioration of its normal function, such as decreased range of motion, and weakened grip strength . However, the disease may be asymptomatic in the early stages. Patients who present with the condition are frequently males in the age of 20 to 40 years old and and manual workers. They also might have history of work that involves repetitive injury or load on the wrist.
Physical examination may reveal swelling and tenderness around the joint, which raises the suspicion and requires further workup. Magnetic resonance imaging (MRI) is the best tool to diagnose Kienbock's disease in early stages. Findings on X-rays may not develop until late stages of the condition. Wrist pain may be the only symptom at presentation; however, MRI will confirm the diagnosis. Other tools that help in making the diagnosis include CT scans of the bone.
MRI is the best tool to make an early diagnosis of the condition, especially when X-ray findings are still unclear. However, as the disease progresses the findings on X-ray become more prominent and clear. X-rays are also used to confirm the presence of negative ulnar variance.
Kienbock's disease is divided into five stages , which are:
CT scans may be used to help in the diagnosis of the condition, especially in early stages; however, MRI is more sensitive and specific than CT scans .
The management of Kienbock's disease depends mainly on the severity and the stage of the condition  . In early stages, medical management with nonsteroidal anti-inflammatory drugs may be sufficient to control the pain and the inflammation. Immobilization and decreasing stress and load on the wrist will also help in the management of the condition.
In late stages, medical treatment becomes ineffective and surgical intervention is required aiming to reduce stress and load on the wrist in order to relieve the pain  . The most commonly used procedure is the correction of negative ulnar variance, if present. In this procedure, the length of the ulna is increased or the length of the radius is decreased, in order to neutralize the wrist joint and relieve the stress and load on the lunate bone. The position of the scaphoid bone is also fixed, if it was abnormal due to the degenerative changes. Other procedures, such as carpectomy or wrist arthrodesis, may be used in late stages of the disease and when all other options fail .
Physical and hand therapy may be useful in maintaining the function of the wrist joint and decreasing the disability. However, it does not treat the condition neither does it affect the course of treatment, and medical or surgical management will still be required.
The prognosis depends on the severity and the stage of the disease. The earlier the diagnosis, the easier the management and the better the prognosis. Bad prognosis with destructive changes to the wrist may occur in late stages, which requires surgical intervention as medical management will not be sufficient.
The main etiologic factors for the development of Kienbock's disease are unknown. However, repetitive trauma and injury to the wrist are believed to be important risk factors. Patients who present with the condition usually have history of wrist trauma or repetitive wrist injury, often due to manual labor , which leads to blood compromise and osteonecrosis, resulting in the development of the condition.
Skeletal changes or variations have been noticed to be associated with the condition, especially negative ulnar variance, which means that the ulna is shorter than its normal length  . The shape of the lunate is also abnormal in some cases, which is believed to be associated with the development of the condition. Medical diseases or conditions affecting the blood vessels of the lunate bone may result in blood compromise and the development of the disease.
Kienbock's disease is a rare condition that usually affects the dominant hand in men more than women (it is very rare among children) . Patients who develop the condition are usually between the age of 20 to 40 years and manual workers.
Normally, only 20% of the axial load through the wrist is transmitted through the ulnocarpal joint, which is increased in the case of negative ulnar variance, and 80% through the radiocarpal joint. In the early stages of Kienbock's disease, the scaphoid bone prevents excessive loads on the lunate; however, as the disease progresses, the scaphoid bone flexes and changes its position, which results in increased loads on the lunate, leading to more damage and progression of the disease .
The changes observed in Kienbock's disease are similar to those of avascular necrosis of any other bone, which includes hyperemia and bone infarction due to disruption of blood supply. The lunate bone has single blood supply in 30% of normal people, which makes it one of the most susceptible bones to osteonecrosis if this single blood supply is compromised.
It is not easy to prevent the development of Kienbock's disease because the main etiologies or causes of the condition are unknown. However, it is useful to raise awareness about the condition and how reducing repetitive injury or heavy load on the wrist may decrease the risk of developing the disease. Reducing weight and stress on the wrist may also help in the prevention of complications and decreasing the progression of the condition if diagnosed.
Certain exercises that add more load and stress on the wrist joint may be restricted if the condition was diagnosed, in order to decrease the progression of the condition and the degenerative changes.
Kienbock's disease is a relatively rare condition affecting the lunate bone. The disorder is more common in men compared to women and the exact etiology of the condition is unknown ; however, the blood supply of the lunate bone is compromised leading to damage and destruction of the bone (osteonecrosis) . Repetitive injury to the wrist is one of the main risk factors in developing the condition.
Symptoms of Kienbock's disease include pain, weakness, and swelling of the wrist, as well as other mechanical symptoms affecting the function of the wrist. However, in early stages, the condition may be asymptomatic. X-ray findings include sclerosis, cystic changes, fragmentation, and articular surface collapse of the lunate bone. However, these findings may not be clear in the early stages of the disease, which makes the diagnosis difficult  . It is advised to use magnetic resonance (MRI) to diagnose the condition in early stages. The earlier the diagnosis of the disease, the easier the management and the better the prognosis.
Management and treatment depends on the severity and stage of the disease. Medical treatment is sufficient in early stages, however, surgical intervention may be needed as the condition progresses.
Kienbock's disease is a rare condition that affects one of the bones in the wrist. This disease usually occurs in men more than in women and it is related to increased stress and load on the bones of the wrist, which leads to damage and degeneration in one of these bones (called the lunate bone) due to loss of its blood supply.
The main cause behind the development of this condition is unknown. However, the damage and degeneration in the bone occurs as a result of the lack of blood supply. Activities and other risks which increase the load and stress on the wrist bones are believed to be associated with the development of the condition, like for example work that involves repetitive injury or trauma to the wrist.
Patients who develop the condition may not know that they have the disorder for several months and the symptoms may not be clear in the early stages of the disease. However, once the symptoms start to develop they include mainly pain and weakness in the wrist, which could be accompanied by swelling in the area.
Once the diagnosis is suspected, the doctor will order further workup to confirm the diagnosis, which includes X-rays, MRI, and CT scans. The X-rays may not be useful in the early stages of the disease, and here comes the importance of MRI in early diagnosis of the disease.
The treatment of Kienbock's disease depends on the stage and the severity of the condition. In early stages, immobilization and medical treatment with nonsteroidal anti-inflammatory drugs may be enough to relieve the pain. However, as the disease progresses, medical treatment becomes ineffective, and surgical intervention is needed to decrease the pain and degeneration in the bones by minimizing the stress and load on the wrist bones. Several surgical procedures may be used in the management of the condition, and the choice of the procedure depends on the severity of the disease.
Outcomes of the disease depend on the stage. The earlier the diagnosis of the disease, the better the outcome and the less the damage and degeneration that may occur. Because the main causes of Kienbock's disease are unknown, it is not easy to prevent the condition. However, awareness and education about the condition and how to decrease load and stress on the wrist may help in decreasing the risk of developing it.
Prevention of degeneration and severe progression of the condition is important once the diagnosis is made. This includes mainly education about how to minimize load on the wrist, and the physical activities that should be avoided because they increase stress and load on the wrist and may worsen the condition. Loosing weight may also help in decreasing the pain and minimizing the degenerative effects.