两种不同几何构型穿钉法治疗股骨颈骨折的生物力学研究

BIOMECHANICAL RESEARCH OF TWO DIFFERENT GEOMETRIC CONFIGURATION CANNULATED SCREW FIXATION IN TREATING OF FEMORAL NECK FRACTURE

目的 通过生物力学分析对两种不同构型固定方法对比评价，以指导临床工作。方法 选择新鲜的成人尸体７具，取双侧股骨１４根， 随机分两组后制做ｐａｕｗｅｌ＇ｓ角≥７０°内收型完全骨折的病理模型。再将两组标本分别施三根加压螺纹钉正、反三角形内固定术后进行力学测试。测试采用电测法。测试指标包括股骨颈施力侧应变值，轴向刚度及侧方刚度，扭转应变值、极限。结果 反三角形固定组的主要力学指标如股骨头位移值（水平向位移值除外）、轴向及侧方刚度、极限载荷和屈服极限均优于正三角形固定组，两者差异显著(Ｐ＜０．０５)；而在股骨头水平向位移值及扭转应变值两种固定则无显著差异(Ｐ＞０．０５)。结论 依据生物力学测试结果可知，反三角形内固定法比正三角形内固定法更符合生物力学要求，为临床应用提供了理论基础。

Objective To compare the biomechanical properties of two different fixation. Methods Fourteen cadaver femure were used in the study. complete fractures of femoral necks were induced with Pauwel＇s angle more than 70 degrees and divided into two groups rendomly which were fixed by cannulated screw fixation with two different geometric contiguration of positive or negative triangle respectively. The biomechanical properties of two different fixation were evaluated. Results Main mechanical properties in negative triangle group such as tensile strain compressive strain displacement of femoral head (except horizontal displacement) axial and lateral rigidity ultimate load and yielding limit were significantly better than in positive triangle group (p<0.05). Conclusion Through biomechamal test we concluded that negative triangular internal fixation were better conformed to biomechanical demanded of fixation of femoral neck fracture than positive triangle group.