股骨头表面置换后股骨近段的生物力学研究

目的探讨股骨头表面置换术对股骨近段生物力学性能的影响。方法集8具青年正常新鲜髋关节标本,建立静止单腿站立位股骨头受力模型,WD-5生物力学测试机测试1000N载荷下股骨头表面置换前后的载荷-应变关系、近段股骨应力分布、刚度和扭转力学性能。结果载荷为1000N时,置换前后的平均应变、最大平均应力、最大平均位移、刚度等指标的测试结果,经统计学处理均无显著性差异(P>0.05)。表面置换前后最大扭矩值相差19%,有显著差异(P<0.05)。结论表面置换能有效维持近段股骨的正常应力传递,从而能有效保留近段股骨的骨量,为日后翻修提供良好条件。表面置换是适用于年轻患者的过渡性手术。

Biomechanical experiment of hip surface replacement

Objective To explore the effect of hip surface replacement on the mechanical characteristics of proximal femur.Method Eight cases of young fresh normal femoral specimens were selected and one leg in standing position was used in the measurement.The biomechanical test was performed on the WD-5 type machine to detect the relation of loading and strain,distribution of stress,rigidity,torsion of normal proximal femur and resurfaced proximal femur under the loading of 1000N.Result No significant difference was found in the relation of loading and strain,distribution of stress and rigidity between normal proximal femur and proximal femur with surface replacement.The maximal torsion between normal proximal femur and proximal femur with surface replacement was 19%,which showed significant differences.Conclusion The hip surface replacement could maintain normal transfer of load to the proximal femur,and avoid resorption resulting from stress shielding similar to THA,therefore it can preserve the proximal bone stock around femoral stem and make the consequent revision easy.It is an effective solution suitable for young patients.