四种髓内针固定股骨中下段骨折的生物力学比较

Evaluation of four types of intramedullar nails for the fixation of femoral shaft fracture: a comparative study of their biomechanical properties

目的研制一种新型的髓内内固定器械一带内锁髓内针，对其生物力学性能进行测试，为临床安全应用提供依据。 方法采用 ６副新鲜人股骨标本，人为造成股骨中下 １／３骨折并 ２ ｃｍ的骨缺损，分别用自带内锁髓内针、国产的交锁髓 内针、Ｅｎｄｅｒ氏针和梅花针内固定，对内固定后的标本进行生物力学测试，用ＳＰＳＳ统计软件对实验数据进行分析。结 果自带内锁髓内针的抗短缩刚度、抗旋转刚度接近于交锁髓内针，抗弯曲刚度优于交锁髓内针。梅花外、Ｅｎｄｅｒ氏针的 抗短缩、抗旋转、抗三点弯曲刚度明显较自锁针和交锁针差。结论自带内锁髓内针内固定在治疗长骨骨折中固定可 靠，符合生物学固定的要求。该器械结构合理、安全、简单、实用，有一定的临床应用价值。

Objective To evaluate the biomechanical property of self-bring interlocking intramedullar nail, a self-made fixation apparatus for femoral shaft fracture. Methods Six pairs of fresh moist femurs were obtained from adult cadavers to produce fracture models of the femur shaft at the lower 1/3 part, with 2 cm bone defect. The femurs were divided into 2 groups (n=6). Medina nails and self-bring interlocking nails were used in group 1,while Ender's nails and the interlocking nails to fix the femur were adopted in group 2. The biomechanical parameters of the nails were measured and the result processed with SPSS software. Results The self-bring interlocking nails possess less rigidity against rotation and axial displacement than the interlocking nails did, but the difference was not statistically significant. The former, however, had better rigidity against bending than the latter did. In terms of these 3 indexes, the meihu and Ender's nails were visibly inferior to the other 2 nails. Conclusion Self-bring interlocking nail possesses good biomechanical property and can produce firm fixation for long bone fracture,thus being of value in the future clinical practice.