股骨颈骨折三种内固定构型的稳定性比较研究

A comparative study of the stability of three configurations of the three pin fixation for the treatment of femoral neck fracture.

目的 通过力学疲劳实验对 30个成人股骨标本进行股骨颈骨折三种内固定构型稳定性比较研究 ,为临床选择固定构型及能否术后立即承重提供依据。方法 采用力学疲劳试验来模拟人体行走中的循环加载方式 ,对股骨颈骨折三针内固定构型进行稳定性的比较研究。结果 股骨颈头下型骨折三针内固定组刚度明显大于头颈型骨折组 (P <0 0 5 ) ;股骨颈头颈型骨折三种三针内固定构型有显著性差异 (P <0 0 5 )。其中倒三角形固定构型组刚度明显大于直角三角形组 ;疲劳加载至 3倍体重(2 1kN)时 ,93%骨—三针内固定构件被损坏 ;疲劳加载达 5倍体重 (3 5kN)时 ,所有构件都被损坏。结论 对于无后侧皮质缺损的股骨颈头颈型骨折 ,在三种三针内固定构型中以倒三角形固定构型为佳。实验结果不支持股骨颈骨折多针内固定后早期负重行走。

Objective [HT5”SS]Thirty human femur specimens were used as mechanical fatigue models to compare the stability of the three configurations for internal fixation in the treatment of femoral neck fracture,in order to provide a foundation for clincal choice and to delineate whether it is feasible to allow immediate full weight bearing following pins/screws fixation of femoral neck fractures.[HT5”H]Methods [HT5”SS]Mechanical fatigue test was used to simulate the circulating loading mode during ambulation.The fixation stability of the three pin configurations was compared.[HT5”H]Results [HT5”SS]The stiffness of three pin configurations in the group of subcapital femoral neck fracture (n=15) was much greater than that in the group of transcervcical femoral neck fracture (n=15) ( P <0 05);In the group of transceravical femoral neck fracture the fixation was stronger ( P <0 05)in the inverse triangle configuration compared with the right triangle type.93% of the bone fixation components were damaged when the fatiguing load was three times the normal weight(2 1 kN);none of the components were intact under the load of five times of the normal weight (3 5 kN).[HT5”H]Conclusion [HT5”SS]For the transcervical femoral neck fracture without posterior comminution,the inverse triangle configuration should be the best for clinical selection.Results of the biomechanical study did not support immediate early ambulation with full weight bearing. [WT5”HZ]