图像相关法测试股骨近端骨小梁压缩特性

目的改善传统方法做压缩测试的不足,更准确地反映骨小梁的压缩弹性模量,探究股骨近端骨小梁的压缩生物力学特性,为临床诊疗提供实验室依据。方法运用微材料力学测试系统,对正常国人(45～60岁)尸体股骨近端骨小梁沿主压力方向及与其垂直方向的压缩性能进行实验研究。结果测得了股骨近端骨小梁在主压力方向压缩弹性模量为(335.26±183.85)MPa,与其垂直方向的压缩弹性模量为(59.27±23.88)MPa,骨小梁在主压力方向上的生物力学性能要明显高于主张力方向;记录了载荷下的骨小梁的位移及应变分布图,负载时骨小梁的位移及应变分布是不均匀的。结论应用微材料力学测试系统测试股骨近端骨小梁压缩弹性模量以更准确地反映其力学性能的方法是可行的,股骨近端骨小梁的压缩性能具有各向异性和不均匀性。

Test on compressive properties of trabecular bone in proximal femur using digital image correlation technique

Objective To improve the method used for traditional compression test to reflect the compressive elastic modulus of trabecular bone in proximal femur more accurately and investigate its biomechanical properties to provide experimental evidences for clinical treatment. Methods The properties of trabecular bone from normal cadaveric proximal femur(45~60 years old) were measured by the micro material mechanics testing system. Results The elastic modulus in the direction of principle compression and principle tension on trabecular bone were (335.26±183.85) MPa and (59.27±23.88) MPa, respectively. The biomechanical properties of trabecular bone in the direction of principle compression were significantly higher than those in its vertical direction.The displacement and strain distribution profiles under the loading were recorded, which showed to be asymmetric. Conclusions It is feasible to test the biomechanical properties of trabecular bone more accurately by the micro material mechanics testing system. The compressive properties of trabecular bone in proximal femur are obviously anisotropic and heterogeneous.