Which bone is most commonly affected in a condition known as Keinbock's disease?

Keinbock's disease, also known as osteonecrosis of the lunate, primarily affects the lunate bone in the wrist. This condition occurs when there is a disruption of the blood supply to the lunate, leading to its degeneration. The lunate is one of the carpal bones and plays a crucial role in wrist movement and stability.

The exact cause of Keinbock's disease is not completely understood, but it has been associated with factors such as trauma, repeated stress on the wrist, and vascular factors. Common symptoms include wrist pain and swelling, and wrist motion may become limited as the condition progresses.

In contrast, the other bones listed—capitate, navicular (also known as scaphoid), and pisiform—are not typically associated with Keinbock's disease. The navicular can be affected by other conditions, such as fractures, and while the capitate and pisiform bones are integral to wrist structure and function, they do not directly relate to the pathophysiology of Keinbock's disease. Understanding the specific association between the lunate and this condition is crucial for recognizing its clinical implications and diagnosis.