Ten fresh human upper-extremity cadaver specimens were tested for the
effect of residual angulation from simulated fractures of both bones of the
forearm on the potential for range of rotation of the forearm and for
limitations of pronation and supination specifically. Ten and 20-degree
angulations for the radius and ulna, such as might be encountered in all
reasonable clinical situations, were tested. Little significant loss of
forearm rotation resulted from angulations of 10 degrees in any direction.
With 20 degrees of angulation, there was statistically significant and
functionally important loss of forearm rotation. Clinical Relevance: A
residual angulation of 10 degrees in mid-shaft fractures of the radius,
ulna, or both bones of the forearm will not limit forearm rotation
anatomically. Loss in the range of rotation can be expected with residual
angeles of 20 degrees or more.