髓内螺钉固定用于髋臼横断骨折的生物力学研究

Biomechanical study of transverse acetabular fracture treated with intramedullary screw fixation

目的探讨髓内螺钉固定用于髋臼横断骨折的生物力学特性,为临床应用提供理论依据。方法选取5例成人髋关节,模拟髋臼横断骨折,采用髓内自加压钉、空心钉2种内固定,进行骨折部位分离位移、应力、载荷的大小测量。结果①髓内自加压螺钉固定在800N时,其纵向位移、水平位移比采用髓内空心钉要小,有显著性差异(P<0.05);②800N载荷作用下,髓内自加压钉的轴向刚度、水平剪切刚度较空心钉大,具有显著性差异(P<0.05)。结论髓内自加压螺钉对髋臼横断骨折固定的效果优于空心钉。

Objective To analyze the biomechanical characters of transverse acetabular fractures in different intramedullary screw fixation options and provide the theoretical foundation for its clinical application. Methods Five adult hip joints fixed by for- malin were used for the transverse aeetabular fracture model and then fixed by intramedullary self-compression screw and intramedul- lary cannulated screw, respectively. The separation displacement, stress and load of fracture position were measured. Results ① When the axial compressive load was 800N, the longitudinal and horizontal displacements of the fracture fixed by intramedullary self-compression screw were significantly smaller than those fixed intramedullary cannulated screw （P 〈 0.05）. ② The axial rigidity and the horizontal shear stiffness of intramedullary self-compression screw fixation were significantly larger than those of intramedul- lary cannulated screw fixation （/9 〈 0.05）, when the stress load was added to the 800N. Conclusion The effectiveness of self-com- pression screw intramedullary fixation is better than cannulated screw intramedullary fixation in transverse aeetabular fracture.