The outcome of 260 repairs of the radial and posterior interosseous nerves, graded by Seddon’s modification of the Medical Research Council Special Committee’s system, was analysed according to four patterns of injury; open ‘tidy’, open ‘untidy’, closed traction, and those associated with injury to the axillary or brachial artery. We studied the effect on the outcome of delay in effecting repair and of the length of the defect in the nerve trunk.

Of the 242 repairs of the radial nerve we found that 30% had good results and 28% fair; 42% of the repairs had failed. The violence of injury was the most important factor in determining the outcome. Of the open ‘tidy’ repairs, 79% achieved a good or fair result, and 36% of cases with arterial injury also reached this level. Most repairs failed when the defect in the nerve trunk exceeded 10 cm. When the repairs were carried out within 14 days of injury, 49% achieved a good result; only 28% of later repairs did so. All repairs undertaken after 12 months failed. Of the 18 repairs of the posterior interosseous nerve, 16 achieved a good result.

We have analysed the results of repair of traumatic lesions of the musculocutaneous nerve in 85 patients, which were graded by Seddon’s modification of the Medical Research Council system into three types of injury: open ‘tidy’, open ‘untidy’and closed ‘traction’. They were also correlated with associated arterial injury.

There were 57 good, 17 fair and 11 poor results. The type of injury was the most important factor in determining the result; 12 of 13 open-tidy lesions gave good results compared with 30 of 48 closed-traction lesions. The results were better when the nerves were repaired within 14 days of injury and when grafts were less than 10 cm long. They were worse in the presence of associated arterial or bony injury.