目的对比轴向载荷下PMMA模型股骨与防腐股骨的生物力学性能差异,为实验工作者提供较为可靠统一的股骨替代模型。方法选取PMMA模型股骨和防腐股骨各10根,分别在两种股骨的内外两侧共粘贴49枚应变片,轴向动态连续加载1.2kN载荷,记录各点应变值及载荷-位移变化情况。结果两种股骨内外侧的应变变化情况相近,载荷一位移关系均呈线性,不同载荷下两种股骨的轴向位移有统计学差异(P〈0.05);PMMA模型股骨和防腐股骨的轴向抗压刚度分别为(259.84±24.63)、(600.40±78.56)N/mm,有统计学差异(P〈0.01);两种股骨在股骨近端的应变集中部位相同,但平均应变值应变片1~5号:PMMA模型股骨和防腐股骨分别为(-3420.63±373.31)、(-1289.42±417.89)με;26~27号:PMMA模型股骨和防腐股骨分别为(1748.67±193.98)、(673.42±104.49)με;7~10号:PMMA模型股骨和防腐股骨分别为(-4028.25±267.27)、(-1139.01±288.83)με;30~36号:PMMA模型股骨和防腐股骨分别为(1599.02±194.68)、(590.52±153.18)με,有统计学差异(P〈0.01)。两种股骨在股骨远端的应变集中部位不同,内外应变正负转变的部位相近;2、26号、6、29号、8、33号应变片的应变值均与载荷呈线性关系,但是两者应变值的差异有统计学意义(P〈0.05)。结论PMMA模型股骨在一定程度上可以替代防腐股骨进行股骨中上部的轴向生物力学研究。在股骨获得日益困难的情况下,它为实验工作者提供了较为可靠统一的股骨替代模型。
Objective To compare the differences in biomechanical properties of embalmed and PMMA femurs under axial loads, so as to provide a more reliable and unified femoral model for replacement. Methods Ten embalmed femurs and ten PMMA femurs were selected, and each femur was instrumented with 49 strain gauges totally on the medial and lateral side. The axial load was applied dynamically up to a maximum of 1. 2 kN, and the strain of each strain gauge and load-displacement curve were recorded. Results The strain distributions on two types of femur were similar, and the load-displacement presented a linear relationship, but the vertical displace- ments under different loads were significantly different (P 〈0.0,5). The axial stiffness value of PMMA femur and embalmed femur were (2,59.84 ± 24.63) and (600.40 ± 78.56) N/mm, respectively, showing significant differ-ence ( P 〈0.01). The strain concentration parts at the proximal part of two femurs were the same, but the aver- age strain value of the PMMA femur was significantly different from that of the embalmed femur ( strain gauge No. 1 -5: PMMA femur ( -3 420.63 ±373.31) με, embalmed femur ( -1 289.42 ±417.89) με; strain gauge No, 26 - 27 : PMMA femur ( 1 748.67 ± 193.98) με, embalmed femur (673.42 ± 104.49) με; strain gauge No. 7 - 10: PMMA femur ( -4 028.25 ±267.2?) με, embalmed femurs ( - 1 139.01 ±288.83) με; strain gauge No. 30 -36: PMMA femur ( 1 599.02 ± 194.68) με, embalmed femurs (590.52 ± 153.18) με, P 〈 0.01 ). The strain concentra- tion parts at the distal part of the two femurs were different. The medial and lateral parts of strain transformation between positive and negative of PMMA femurs were similar to embalmed femurs. The strain-load curves of strain gauge No. 2, 26, 6, 29, 8 and 33 indicated a linear relationship, but the strain value of the two femurs had significant differences ( P 〈0.05). Conclusions The PMMA femur can replace the embalmed femur to a ce