The influence of lateral and anterior angulation of the proximal ulna on the treatment of a Monteggia fracture: an anatomical cadaver study.

We have investigated the anatomy of the proximal part of the ulna to assess its influence on the use of plates in the management of fractures at this site. We examined 54 specimens from cadavers. The mean varus angulation in the proximal third was 17.5 degrees (11 degrees to 23 degrees ) and the mean anterior deviation 4.5 degrees (1 degrees to 14 degrees ). These variations must be considered when applying plates to the dorsal surface of the ulna for Monteggia-type fractures. A pre-operative radiograph of the contralateral elbow may also be of value.