人股骨头大孔径髓芯减压后支撑架植入生物力学分析

Biomechanical study of titanium alloy cage implantation for the large aperture core decompression of femoral head

[目的]观察钛合金支撑架植入对经转子大孔径髓芯减压后人股骨头力学强度的影响。[方法]取新鲜人股骨头9对,随机分成3组,每组3对。其中2组随机选取每对中的一侧,分别模拟经股骨颈大孔径(D=16mm)单纯髓芯减压、大孔径髓芯减压+钛合金支撑架植入治疗股骨头坏死的方法做成治疗后的状态,另一侧做正常对照,第3组随机选取其中一侧模拟经股骨颈大孔径单纯髓芯减压,另一侧模拟经股骨颈大孔径髓芯减压+钛合金支撑架植入,在AGS-10KND万能生物材料实验机上进行力学性能测试,观察3组标本股骨头的力学刚度及强度,对每对标本的实验结果标准化后进行统计学分析。[结果]单纯大孔径髓芯减压组和正常对照组力学曲线成单峰状,大孔径髓芯减压+钛合金支撑架植入组力学曲线呈双峰状。单纯大孔径髓芯减压组刚度及最大负载明显低于正常对照组(P<0.05),钛合金支撑架植入组初峰刚度及最大负载与正常对照组无明显统计学差异(P>0.05),次峰最大负载明显高于正常对照组(P<0.05)。[结论]经转子大孔径髓芯减压会明显降低股骨头负重区的力学强度。钛合金支撑架植入能给股骨头负重区软骨下骨提供足够的机械支撑力,起到防止股骨头塌陷,维持股骨头外形的作用,有利于坏死股骨头的再生和修复。

[ Objective ] To study the biomechanics effect of large aperture （D = 16mm） core decompression and the use of alloy cage in femoral head. [ Method] Nine couples of fresh moist human＇s femur specimens were divided randomly into 3 groups. In 2 groups, biomechanical test of the femoral neck was made for one of every couple in different conditions ： large aperture core decompression （group 1 ） ,large aperture core decompression with titanium alloy cage （group 2 ）implant. The other one of every couple was tested as normal control. In the third group, one of every couple was tested in condition of large aperture core decom- pression with titanium alloy cage implanting. The other one of every couple was tested in condition of large aperture core decom- pression. [ Result ] The load-displacement curve of group 1 and the normal control had single peak, and the curve of group 2 had double peaks. The stiffness and the max load of group 1 were much less than that of the normal control （ P 〈 0.05 ）. There were no statistic differences of the stiffness and the max load between group 2 in the first peak and the normal control （ P 〉 0.05 ）, but the max load of group 2 in the second peak were much lager than that of the normal control （ P 〈 0.05 ）. [ Conclusion ] The large aperture core decompression could decrease mechanical support for femoral head significantly. The titanium alloy cage implant could afford enough power for mechanical support of femoral head. It was beneficial for sustaining the shape of femoral head. This treatment can be used for the ischemic necrosis of femoral head.