الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Ulnar variance is the relative length of the ulna in relation to the radius at the level of the wrist. Ulnar variance can be measured on plane radiograph by extending a line along the distal articular surface of the radius toward the ulna and measuring the distance from this line to the distal ulna. When the length of the distal ulna exceeds the length of distal radius by 1 mm or more, UV is considered positive, and it is negative when the length of the distal ulna is less than the length of distal radius by 1 mm or more. When the relative length of the distal radius and ulna differ by less than 1 mm, UV is labelled as ‘neutral’ variance.The consequences of negative ulnar variance are increased force applied to the radial side of the wrist and to the lunate bone, which may explain the association of negative ulnar variance and Kienbock’s disease. With such variance, the triangular fibrocartilage complex (TFCC) is thicker, and degeneration of the TFCC are uncommon. A consequence of positive ulnar variance, is the ulnar impaction syndrome, with resulting limitation of rotation. The TFC is thinner in instances of positive ulnar variance, with possible degenerative perforation. Clearly, a standard radiographic view is necessary to help reliably determine ulnar variance. The generally accepted standard view is a posteroanterior view obtained with the wrist in neutral forearm rotation, the elbow flexed 90° and the shoulder abducted 90°.