锁定钢板与伽马钉三代修复股骨转子间骨折:生物力学稳定性比较

Locking plate fixation versus the third generation of the gamma nail fixation for intertrochanteric fractures: biomechanical stability

背景:老年人股骨转子间骨折使用伽马钉三代(Gamma3)治疗时,可能使骨折块分离,难于固定小转子使稳定性差,易出现髋内翻畸形,则较难支撑及满意复位。目的:比较股骨近端锁定钢板与Gamma3治疗稳定型股骨转子间骨折后的效果及稳定性。方法:1纳入64例股骨转子间骨折患者,分别采用Gamma3内固定(n=32)和股骨近端锁定钢板内固定(n=32)进行治疗,通过X射线正、侧位片评估骨折复位及愈合情况,并对股骨转子内翻角、股骨转子内侧后倾角进行生物力学测试。2选取形态、大小近似的8对股骨标本,随机分为Gamma3组和股骨近端锁定钢板组(n=4),分别采用Gamma3内固定和股骨近端锁定钢板内固定,轴向压缩试验和破坏试验后描绘载荷-位移曲线,采用扭转试验计算最大屈服载荷值。结果与结论:股骨近端锁定加压钢板内固定组患者手术时间、术中出血量多于Gamma3内固定组(P<0.05)。股骨近端锁定加压钢板内固定组患者骨折复位质量评定结果优于Gamma3内固定组(P<0.05)。股骨近端锁定加压钢板组股骨标本轴向刚度及各扭转角相应扭矩均小于Gamma3组(P<0.05)。说明在固定合并大转子骨折的股骨转子间骨折中,股骨近端锁定钢板更具有生物力学上的稳定性。

BACKGROUND： Being used in senile intertrochanteric fracture, the third generation of Gamma nail may isolate fracture fragments and it is difficult to be secured in the rotor, so the stability is poor. Varus deformity easily appears, which is difficult to support or satisfactorily reset. OBJECTIVE： To compare the effects and stability of the proximal femoral locking plate and the third generation of the gamma nail in the treatment of stable intertrochanteric fracture. METHODS：（1） A total of 64 patients with intertrochanteric fractures were respectively treated with the third generation of the gamma nail fixation（n=32） and proximal femoral locking plate fixation（n=32）. Fracture reduction and healing were assessed using anteroposterior and lateral radiographs. Femoral rotor varus angle and intertrochanteric medial inclination received biomechanical measurement.（2） Eight femoral specimens whose shape and size were approximated were selected to be randomly assigned to Gamma 3 group and proximal femoral locking plate group（n=4）, which respectively received Gamma 3 fixation and proximal femoral locking plate fixation. After axial compression test and destruction test, load-displacement curve was drawn. The maximum yield load value was calculated by torsion test. RESULTS AND CONCLUSION： Operative time and intraoperative blood loss were significantly more in the proximal femoral locking plate group than in the Gamma 3 group（P〈0.05）. The fracture quality assessment results were better in the proximal femoral locking plate group than in the Gamma 3 group（P〈0.05）. The axial stiffness and corresponding torque of various torsion angles were smaller in the proximal femoral locking plate group than in the Gamma 3 group（P〈0.05）. Experimental results indicated that in the course of fixating intertrochanteric fracture merged with greater trochanter fracture, the proximal femur locking plate has obtained more biomechanical stability.