Radial nerve injury secondary to use of hinged elbow external fixators

Objective To discuss causes and treatment outcomes of radial nerve injury related to hinged external fixators applied to the elbow,enhance understanding of the injury and thereby reduce its clinical incidence.Methods The study involved five cases who experienced radial nerve injury in the wake of application of unilateral hinged external fixators to the elbow.Exploration and neurolysis was perfomed at 3-12 weeks after injury since no signs of nerve recovery.Afterwards,follow-up was made for all cases.Results Causes of radial nerve injury were as follows:proximal humerus Schanz screws stretched and compressed radial nerve by tethering soft tissues into cicatricial bands in two cases; distal humerus Schanz screws compressed radial nerve by tethering soft tissues adjacent to radial nerve to cicatricial bands in one case; distal humerus Schanz screws compressed radial nerve in motion of the elbow by tethering thickened intermuscular septa and further forcing the enlargement of muscle force in two cases.Forces of muscles supplied by radius nerve reached fourth or fifth rank at postoperative one-year follow-up.Conclusions Radial nerve is vulnerable in the application of unilateral hinged external fixators to the elbow due to its special path and relative stability.Accordingly,injury to radial nerve can be reduced and even avoided by knowing its anatomy features and standardizing the operation in use of external fixators.Exploration and treatment immediately after the confirmation of radial nerve injury can achieve good prognosis. Key words: Elbow joint; Radial nerve; External fixators