Vascularity of the lunate. Anatomic studies and implications for the development of osteonecrosis.

Osteonecrosis of the lunate is well established as the pathologic entity underlying the clinical condition known as Kienböck's disease. Consequently, the extraosseous and intraosseous blood supplies to the lunate have been well studied. A series of three palmar and three dorsal arterial arches provide a consistent volar supply to the lunate, and a frequent, but inconsistent, dorsal supply. Volar and dorsal foramina each generally contribute one to two vessels to a volar and dorsal intraosseous arterial network. The dorsal and volar arterial systems anastomose distal to the midline of the lunate; however, in as many as 7.5% of lunates, no anastomosis my be present. Between 7% and 26% of lunates may lack either a volar or dorsal arterial supply. These findings have significant implications regarding possible mechanisms for the development of osteonecrosis and the treatment of Kienböck's disease.