股骨颈骨折几种内固定方法的生物力学研究

为探讨符合生物力学原理的股骨颈骨折的固定方法，为临床应用提供理论基础。用7具成人新鲜股骨上段标本，制成内收型股骨颈头颈型骨折。随机分成4组，A组用2孔动力髋螺钉（danamic hip screw DHS）固定，B组用3枚空心加压螺钉固定（cannulated compression screw CCS），C组用三翼钉（Smith—petersen nail SPN）固定，D组为正常原始骨组（Intact bone IB）。用完整的生物力学实验测定各种固定方法在不同载荷下的载荷．应变值，头下沉位移和偏轴位移，股骨的轴向刚度和扭转刚度，以及应力遮挡率。结果表明，A组的主要生物力学指标如股骨颈张力侧、压力侧载荷．应变值，股骨头水平及下沉载荷．位移曲线，股骨的轴向刚度及应力遮挡率均优于B组和C组。差异有显著性（P〈0.01）。而股骨的扭转刚度测定结果显示，A组和B组无显著差异（P〉0．05）。认为2孔动力髋螺钉固定股骨颈骨折更符合生物力学要求。

BIOMECHANICAL EFFECT ON DIFFERENT FIXATIONS TO TREAT FEMORAL-NECK FRACTURE

In order to study biomechanical effect of the different fixations of treating femoral-neck fracture and provide a basis for the clinical application, models of adductive femoral-neck fracture were established in 7 fresh adult thighbones and divided into 4 groups: group A (fixed by danamic hip screw, DHS ), group B (fixed by cannulated compression screw, CCS), group C(fixed by smith-petersen nail, SPS),group D(intact bone, IB); The biomechanical parameters such as load-variable, displacement of head seaking and deflexion, rigidity of longitudinal in femur and torsion, the covered ratios of stress were observed respectively and compared. The results showed that group A was significant difference between the group B and group C in the all biomechanical parameters (P<0.01), while there was no significant difference between group B and group C in torsion rigidity of thighbone (P>0.05), suggesting that DHS to treat femoral-neck fracture is more reasonable in biomechanical parameters.