Radial Palsy After Hinged External Fixator Application: A Terrible Complication of a Terrible Elbow Triad

Abstract

The use of an external fixator (EF) is getting more and more common in the treatment of elbow fracture-dislocations. However, radial nerve (RN) injury is a major complication. To the best of our knowledge, only 14 cases have been reported in literature. We present the case of a 46-year old man who suffered a complex elbow fracture-dislocation (terrible elbow triad). Closed reduction was performed in the Emergency Room. Five days later the patient underwent scheduled surgery. Osteosynthesis of the radial head and repair of the lateral collateral ligament, coronoid process and the medial collateral ligament was performed. As residual partial instability at more of 60° of extension was observed, an EF was implanted percutaneously. In the postoperative period an incomplete sensory and motor RN injury was found and immediate rehabilitation treatment was indicated. At six weeks postoperative, removal of EF was carried out. Before extracting the pins, a perineurium injury of the RN in the deep plane caused by the most distal humeral pin without transection of the nerve was seen. Scar tissue debridement and suture of the perineurium plus coverage of the injured area with NerveProtector membrane were performed. Intraoperative elbow stability was achieved. After 18 months, the elbow was stable with a range of motion of 30°-120°, 5/5 strength of the wrist and 4/5 for finger extension. The last electromyography showed reinnervation signs. To avoid the iatrogenic injury of the RN, the implantation of an EF in the elbow must be always performed under direct visualization of the nerve.