InterTAN髓内钉治疗股骨转子间骨折术中主钉置入困难的原因分析

Pitfalls in implantation of InterTAN for intertrochanteric femur fracture

目的探讨InterTAN髓内钉治疗股骨转子间骨折术中主钉置入困难的原因及处理方法。方法回顾性分析2008年9月至2013年8月采用InterTAN髓内钉治疗的496例股骨转子间骨折患者资料，男172例，女324例；年龄为32—87岁，平均69．2岁；骨折AO分型：31-A1型29例，31-A2型315例，31．A3型152例。总结术中置入主钉困难的原因及处理方法。结果21例股骨干存在过多向前和（或）侧方弯曲的解剖特异性患者，术中置入主钉困难；5例体型肥胖患者（体质量指数〉30kg／m^2）术中置入主钉困难，其中1例在术中发生医源性骨折；3例老年患者术中置入主钉过程中发生医源性骨折；17例术中复位困难的患者置入主钉困难，其中1例在锁定远端锁钉时发生医源性骨折。结论应用InterTAN髓内钉治疗股骨转子间骨折时应注意：①术前应确定患者股骨是否存在解剖特异性，摄患侧股骨全长正、侧位X线片，以便术中对进钉点作出相应调整；②肥胖患者术中折刀体位要充分，将侧腹部赘肉限制在前侧，保证主钉行进时与股骨髓腔轴线一致；③老年患者应充分重视其骨质的脆弱性，在置入主钉时杜绝暴力操作；④术前评估骨折复位困难时，应将切开复位动力髋螺钉内固定作为备选术式。

Objective To investigate the intraoperative technical difficulties in the implantation of InterTAN for intertrochantefic femur fracture and their Methods A retrospective study was conducted of the 496 patients with intertrochanteric femur fracture who had been treated with InterTAN intramedullary nails from September 2008 to August 2013 at our department. They were 172 men and 324 women, aged from 32 to 87 years at the time of fracture （average, 69.2 years） . According to the AO classification, 29 cases were type 31-A1, 315 cases type 31-A2 and 152 cases type 31-A3. Intraoperative difficulties in implantation of InterTAN intramedullary nails were analyzed and countermeasures were proposed. Results We identified intraoperative technical difficulties in implantation of the main nail in the following situations： in 21 patients who had anatomic variation in femoral shaft （excessive anterior or lateral skewing）, in 5 obese patients in one of whom iatrogenic fracture occurred; in 3 elderly patients, and in 17 patients with hard reduction in one of whom iatrogenic fracture occurred during the locking of a distal screw. Conclusions To deal with the difficulties in implantation of InterTAN for intertrochanteric femur fracture we propose the following 4 countermeasures： 1. Anteroposterior and lateral radiographs of the full length of the injured femur are necessary for preoperative determination of presence or absence of anatomical variations so that implantation can be adjusted during surgery. 2. Vertical trajectory and sufficient reaming in the medullar canal of the proximal femur are important to reduce the possibility of iatrogenic fracture, particularly in obese patients. 3. Violent hammering is prohibited and full reaming is recommended in the elderly whose bone is fragile. 4. For the cases where hard fracture reduction is predicted by the preoperative evaluation, the strategy of open reduction and fixation with dynamic hip screws seems more rational or should be prepared as an alternative method.