A Comparative Study Between Radius and Capitate Shortening in Ulna Minus Variance Kienbock's Disease

1. Kienböck's disease refers to avascular necrosis of the lunate carpal bone, known as lunatomalacia. It was first recognized and described by Austrian radiologist Robert Kienböck's in 1910 2. The lunate is the central bone in the proximal row, and it articulates with the scaphoid, capitate, triquetrum, and occasionally the hamate. More proximally, the lunate is a component of the radiocarpal joint, and it also articulates with the ulna via the triangular fibrocartilage complex (TFCC) 3. The exact cause of Kienböck's is not known, though there are thought to be a number of factors predisposing a person to Kienböck's. Although there is no evidence that Kienböck's disease is inherited, it is possible that unidentified genetic factors could contribute to the development of the condition, It is multifactorial, related to the following variables:Ulnar negative variance (or ulna minus),Vascular supply to the lunate bone,Lunatemorphology,Radial inclination angle,multiple wrist trauma 4. Kienböck's disease is the second most common type of avascular necrosis of the carpal bones, preceded only by avascular necrosis of the scaphoid. The typically affected population is males aged 20-40 years 5. Patients usually present with unilateral pain over the dorsal aspect of the wrist, limited wrist motion, weakness, or a combination of the three. Wrist extension and axial loading exacerbate pain. Symptoms range from mild to debilitating. It is rarely bilateral, and trauma is often absent. Physical examination commonly reveals wrist swelling, tenderness over the expected location of the lunate, synovitis, and loss of grip strength 6. Kienböck's disease is a clinical and imaging diagnosis. Both radiography/computed tomography and magnetic resonance imaging (MRI) are highly specific. However, MRI is the most sensitive and detects radiographically occult cases