应用肘关节铰链式外固定架治疗引起的桡神经损伤

Radial nerve injury secondary to use of hinged elbow external fixators

目的探讨应用肘关节铰链式外固定架引起桡神经损伤的发生原因及治疗结果，以增强对这种损伤的认识，从而减少临床发生率。方法对5例应用肘关节单边铰链式外固定架治疗术后出现桡神经损伤的患者，经随访无神经恢复表现后，在术后3～12周均进行桡神经探查松解术，并进行随访。结果2例因肱骨近端Schanz钉绞缠软组织形成瘢痕索条牵拉卡压桡神经引起，1例因肱骨远端Schanz钉绞缠桡神经邻近软组织形成索条引起桡神经卡压，2例因肱骨远端Schanz钉绞缠增厚的肌间隔，使张力加大，在肘关节活动时卡压桡神经。术后1年随访桡神经支配区域肌力均达4级或5级。结论桡神经因其特殊的走行及相对固定的特点，应用肘关节单边铰链式外固定架时易造成损伤，熟悉其解剖特点并规范外固定架的操作可避免或减少其发生。确诊桡神经损伤后及时行探查和治疗可获得良好的预后。

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 eases who experienced radial nerve injury in the wake of application of unilateral hinged external fixators to the elbow. Exploration land 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.