THE EFFECTS OF DISTAL RADIUS FRACTURE MALALIGNMENT ON FOREARM ROTATION - A CADAVERIC STUDY

Seven fresh cadaveric specimens were used to determine the loss of for earm rotation with varying distal radius fracture malalignment pattern s. Uniplanar malunion patterns consisting of dorsal till, radioulnar t ranslation, or radial shortening were simulated by creating an osteoto my at the distal end of the radius, orienting the distal fragment posi tion using an external fixator, and maintaining the position with wedg es and a T-plate. Rotation of the forearm was produced by fixing the e lbow in a flexed position and applying a constant torque to the forear m using deadweights. Forearm rotation was measured with a protractor D orsal tilt to 30 degrees and radial translation to 10 mm led to no sig nificant restriction in forearm pronation or supination ranges of moti on. A 5-mm ulnar translation deformity resulted in a mean 23% loss of pronation range of motion. Radial shortening of 10 mm reduced forearm pronation by 47% and supination by 29%.