Robert Kienböck (1871-1953), an Austrian radiologist and pioneer in the use of x-ray technology for medical diagnosis and therapy, described a disorder in which the lunate bone in the wrist would break down. Kienbock’s is due to avascular necrosis (lack of blood supply) of the lunate. It is characterised by central wrist pain which can be of insidious onset and gradually progresses as the lunate fragments and collapses. The causes are unknown but several theories exist including trauma (single forgotten trauma or repetitive microtrauma) and increased pressure within the lunate. It tends to affect young adults and is associated with the ulna being relatively shorter than the radius (negative ulnar variance).