We have assessed the influence of isolated and combined rotational malunion of the radius and ulna on the rotation of the forearm. Osteotomies were made in both the radius and the ulna at the mid-diaphyseal level of five cadaver forearms and stabilised with intramedullary metal implants. Malunion about the axis of the respective forearm bone was produced at intervals of 10°. The ranges of pronation and supination were recorded by a potentiometer under computer control. We examined rotational malunions of 10° to 80° of either the radius or ulna alone and combined rotational malunions of 20° to 60° of both the radius and ulna.

Malunion of the ulna in supination had little effect on rotation of the forearm. Malunion of either the radius or of the ulna in pronation gave a moderate reduction of rotation of the forearm. By contrast, malunion of the radius in supination markedly reduced rotation of the forearm, especially with malunion greater than 60°. Combined rotational malunion produced contrasting results. A combination of rotational malunion of the radius and ulna in the same direction had an effect similar to that of an isolated malunion of the radius. A combination in the opposite direction gave the largest limitation of the range of movement. Clinically, rotational malunion may be isolated or part of a complex angular/rotational deformity and rotational malunion may lead to marked impairment of rotation of the forearm. A reproducible method for assessing rotational malunion is therefore needed.

We reviewed a consecutive series of 33 infants who underwent surgery for obstetric brachial plexus palsy at a mean age of 4.7 months. Of these, 13 with an upper palsy and 20 with a total palsy were treated by nerve reconstruction. Ten were treated by muscle transfer to the shoulder or elbow, and 16 by tendon transfer to the hand. The mean postoperative follow-up was 4 years 8 months. Ten of the 13 children (70%) with an upper palsy regained useful shoulder function and 11 (75%) useful elbow function. Of the 20 children with a total palsy, four (20%) regained useful shoulder function and seven (35%) useful elbow function. Most patients with a total palsy had satisfactory sensation of the hand, but only those with some preoperative hand movement regained satisfactory grasp. The ability to incorporate the palsied arm and hand into a co-ordinated movement pattern correlated with the sensation and prehension of the hand, but not with shoulder and elbow function.