新型儿童股骨颈螺钉设计中的生物力学因素

背景：由于骺板在股骨的生长发育过程中有重要的作用，内固定的设计要求尽量避免对骺板的损伤，因此对儿童股骨骺板的定位显得尤其重要。目的：探讨新型儿童股骨颈螺钉固定儿童股骨颈骨折的生物力学性能。方法：由南华大学解剖室提供的6具儿童尸体上取下股骨12根，X射线排除骨病后，分别采用3枚新型儿童股骨颈螺钉固定；3枚2.0 mm克氏针固定。分别进行生物力学实验，测试其轴向压缩、扭转刚度。结果与结论：轴向压缩刚度及最大3 N·m 的扭转力矩下扭转刚度，儿童股骨颈螺钉分别为（190.74±20.88） N/mm、（0.18±0.045） N·m/（°），克氏针为（138.95±15.19） N/mm、（0.120±0.036） N·m/（°），两者比较差异均有显著性意义（P〈0.05）；显示儿童股骨颈螺钉的抗压能力和抗扭能力上明显强于克氏针。实验说明儿童股骨颈螺钉是一种符合儿童股骨近端解剖学特点，能够满足儿童股骨颈骨折需要的新型内固定器械，具有良好的生物力学性能。

Biomechanical factors in the design of new femoral neck screw in children

BACKGROUND：As the epiphyseal plate has an important role in the growth and development of femur, the design of internal fixation should avoid the damage to the epiphyseal plate. Therefore, the positioning of pediatric femoral epiphyseal plate is particularly important.
OBJECTIVE：To investigate the biomechanical property of the new femur neck screw internal fixation in treatment of children femoral neck fracture.
METHODS：Twelve femurs were col ected from six fresh children cadavers provided by Dissecting Room of University of South China. After exclusion of bone disease with X-ray film, three new children femoral neck screws and three Kirschner wires with the diameter of 2.0 mm were used for fixation. The biomechanical tests were conducted to detect the axial compression and torsion stiffness.
RESULTS AND CONCLUSION：In the children femoral neck screw group, the axial compression stiffness and torsion stiffness under the torsional torque of maximum 3 N？m were （190.74±20.88） N/mm and （0.18±0.045） N？m/° respectively;（138.95±15.19） N/mm and （0.120±0.036） N？m/° respectively in the Kirschner wire group;there were significant differences in the axial compression stiffness and torsion stiffness between two groups （P〈0.05）. The results showed that the compressive strength and torsional capacity of the children femoral neck screw were strong than those of Kirschner wire. The experiment suggested that the femoral neck screw for children is a new type of ideal internal fixation device which consist with the anatomical features of children proximal femur and can meet the requirement of children femoral neck fracture with good biomechanical property.