Objective: The aim of the study was to investigate the effect of different arm positions (hand pronation/supination and elbow flexion/extension) on fragment rotation in extra-articular distal radius fractures in a cadaveric model.
Methods: In this study, ten fresh-frozen cadaveric upper extremities from five donors with a mean age of 69 ± 12 years were used. Two cortical pins were inserted in the radius and the ulna. In a custom-made device, different forearm (30°, 60°, and 90° of pronation and supination) and elbow positions (full extension) were tested, using a fluoroscopic analysis. The degree of malrotation between the two pins was measured in these positions. At the last test sequence, the tendon of the brachioradialis muscle was released.
Results: A significant difference was found in concerns of the rotational angle between the distal fragment and the radial shaft at different degrees of pronation and supination if the elbow joint was in an extended and flexed position. The release of the brachioradialis tendon did not show any effect.
Conclusion: The results of this study supported that rotational malpositions in distal radius fractures can be decreased if the forearm is in a neutral position. Accordingly, the forearm should be in a neutral position while initially immobilization in a plaster splint is performed.