What are the major differences between Lunate Dislocation and Kienbock's Disease?

Lunate Dislocation is an acute injury resulting from a high energy mechanism. It's a very serious injury involving the carpal bones and can lead to complications like carpal instability, dysfunction, and chronic pain if not properly addressed.

Kienbock's Disease, on the other hand, is a chronic condition marked by the progressive collapse of the lunate bone usually due to interrupted blood supply, leading to avascular necrosis of the lunate. It's a progressive and debilitating disease resulting in loss of wrist motion and function over time.

What signs and symptoms are usually seen in Lunate Dislocation and Kienbock's Disease?

For Lunate Dislocation, acute pain in the wrist, possible visible deformity, reduced range of motion, and tenderness over the lunate are common symptoms.

In contrast, the symptoms of Kienbock's Disease are usually progressive and more subtle. These may include chronic wrist pain (often on the little-finger side), swelling, decreased wrist motion, and in advanced stages, the wrist may appear collapsed.


What are the diagnostic modalities of choice for Lunate Dislocation and Kienbock's Disease?

Radiographs are the initial diagnostic modality for both conditions. In Lunate Dislocation, PA radiograph shows a 'piece of pie' sign or triangular lunate, and the lateral radiograph demonstrates the 'spilled teacup' sign.

In Kienbock's Disease, initial radiographs may be normal. As the disease progresses, the lunate may appear sclerotic and later shows progressive flattening and fragmentation. In advanced stages, CT or MRI may provide additional information regarding the extent of the lunate collapse and involvement of surrounding structures.

What treatments options are available for Lunate Dislocation and Kienbock's Disease?

The treatment for Lunate Dislocation is usually surgical. The goal is to reposition the lunate and secure the carpal bones, restoring normal joint alignment and relieving pressure.

For Kienbock's Disease, treatment is typically guided by the stage of the disease. Early stages might be managed with immobilization and NSAIDs. In later stages, surgical options may be considered, like lunate decompression, revascularization procedures, or in advanced cases, proximal row carpectomy or even total wrist arthrodesis..