Etiology of Kienböck disease.

The etiology of Kienböck disease is still unknown and, consequently, the ideal treatment is in doubt. Many different hypotheses have been suggested. There are reasons to believe that there are mechanical, vascular, and metabolic factors predisposing to the disease, and probably some factors triggering the development of the process. Among mechanical factors, the short ulna has been thought to be the most relevant. However, presently there are insufficient data to support a significant association between negative ulnar variance and Kienböck disease. With regard to vascular factors, anatomical studies have shown consistent dorsal and palmar arteries entering the bone, and thus, the most likely site for vascular impairment may be at the subchondral level. Many triggering factors have been proposed during the past years, but until this is truly clarified, finding the real cause of Kienböck disease will continue to be a real challenge.