Study on etiology of lunate avascular necrosis

Objective To discuss the etiology of lunate avascular necrosis. Methods After the study of functional anatomy of wrist joint and intra-lunate micro-structure and wrist X-ray, we put forward the factors contributing to lunate avascular necrosis. Results (1) 20% lunate was supplied by single either volar or dorsal blood vessels, completely or mainly,which predisposed to Kienb*ick's disease. (2) Lunate trabeculae correllates with conduction of stress from distal to proximal end. (3) Capillaries in central part is excessive in amount and small in diameter, and capillaries in palmar part is larger than in central part,in which the rate of blood vessels areas to bone sections is the largest, demonstrating that blood supply in volar part is predominant. (4) There was volar flexion deformity of the lunate in abnormal group. Conclusions Kienb*ick's disease is caused by intrinsic and extrinsic factors associntedi with the lunate.