目的 探讨顺时针拧入Gamma-3的拉力螺钉时,是否造成头颈骨块的旋转而加大骨块间分离。方法 回顾性分析2013年1月~12月收治的左侧股骨粗隆间骨折32例,均接受闭合复位Gamma-3内固定治疗。在患肢中立位侧位片上,测量头颈骨块轴线与股骨干轴线的成角,比较该角度在闭合复位后、拧入拉力螺钉后及出院前的变化。结果 在术中拧入头颈部拉力螺钉后,头颈骨块发生顺时针旋转分离的有9例,下方皮质向前上翘起。骨折分型OTA31A2.3,均为不稳定型顺向粗隆间骨折。头颈骨块轴线和股骨干轴线的夹角,骨折闭合复位后为16.78°±4.55°,拧入拉力螺钉后为27.78°±6.0°,回拧后为17.67°±4.30°,出院时为17.89°±3.89°。经统计学分析,拧入拉力螺钉能显著加大头颈骨块的顺时针旋转(P<0.05),反向回拧后分离角度显著减少(P<0.05)。结论 拉力螺钉在拧入头颈骨块时有造成其顺时针旋转的倾向,对左侧粗隆间骨折能加大头颈骨块的旋转分离。

Objective To explore whether insertion of the lag screw into the head-neck fragment in left-sided intertrochanteric fractures can cause fragment rotation and loss of reduction.Methods A retrospectively analysis was performed in 32 patients with left-sided unstable intertrochanteric fracture,who underwent close reduction and Gamma-3 fixation from January to December 2013.The angle between the central axis of head-neck and the central axis of femur shaft in lateral X-ray film was measured,and compared among closed reduction,lag screw insertion,and final state before patient discharge.Result When lag screw was wrenched into the head-neck fragment,rotational displacement was observed in 9 of 32 patients (28%).All the 9 fractures were classified OTA31A2.3.The angle between the central axis of head-neck fragment and femur shaft was 16.78°±4.55° after closed reduction 27.78°±6.0° after lag screw insertion 17.67°±4.30° after back rotation,and 17.89°±3.89° in discharge,respectively.A statistical test revealed a significant difference between closed reduction,lag screw insertion,and back rotation of the lag screw (P<0.05).Conclusion Wrenching-in lag screw can potentially lead to head-neck fragment rotation and loss of fracture reduction in unstable left-sided intertrochanteric fractures.