The causes of Kienböck's disease are unknown. The pathology is thought to arise from previous repetitive injuries of the wrist. The normally poor vasculature in this region seems more likely to increase the predisposition to this disease. The shorter length of the ulna bone in some individuals may deliver excessive pressure on the wrist and affect the integrity of the lunate including the reduction of blood supply. Kienböck's disease can be associated with other medical conditions affecting small vessels and bone integrity (osteoporosis).