This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Avascular Necrosis, Subject name: Orthopaedics
Kienbock disease is avascular necrosis of: 
Select and explain. 
A. Scaphoid, B. Trapezoid, C. Trapezium, D. Lunate
D: Lunate
Answer: D: Lunate 
Explanation: Ans. (d) LunateRef: Maheshwari 5th ed. / 318* It is breakdown of the lunate bone, a carpal bone in the wrist that articulates with the radius in the forearm.* Specifically, Kienbock's disease is another name for avascular necrosis with fragmentation and collapse of the lunate.* This has classically been attributed to arterial disruption, but may also occur after events that produce venous congestion with elevated inter-osseous pressure.