股骨头坏死的部位与人工全髋表面置换术后股骨颈骨折的相关性研究

Biomechanical relation between the region of femoral head becrosis and femoral neck fracture after the total hip resurfacing

目的:通过生物力学实验探讨股骨头坏死缺损的部位与人工全髋表面置换术(MMSA)后发生股骨颈骨折的相关性。方法:选取成年人股骨标本25具,要求生前无髋关节疾患。将其随机分组,分别制造股骨头不同部位(负重区与非负重区)的骨缺损模型(模拟已发生塌陷并且坏死骨被清除后的股骨头缺血坏死模型)。将标本分为正常组、股骨头负重区域的坏死缺损10%、20%与非负重区域的坏死10%、20%,共5组。均在股骨头表面覆盖相匹配的金属假体,模拟单足站立时肢体负重力线的方向,加载一定的重量,直至股骨颈发生骨折为止。并分析股骨头不同坏死部位与股骨颈骨折发生的生物力学相关性。结果:股骨头负重区域坏死的股骨颈强度比非负重区坏死的强度来得小,易发生变形和骨折,差异具有统计学意义(P<0.001)。结论:股骨头负重区域坏死对MMSA术后股骨颈的影响较大,易发生股骨颈骨折。股骨头负重区坏死>20%是MMSA术的相对禁忌证,术后易发生股骨颈骨折。

Objective：To observe and approach the relation between the region of femoral head necrosis and femoral neck fracture after the total hip resurfacing by biomechanics. Methods：Twenty-five normal adult proximal femur were harvested. They were divided into five groups at random the different regions of femoral head necrosis were and simulated ： normal, 10% ,20% both in human femoral bead＇s weight bearing region and 10% ,20% in non-weight beating region ,both of them were tested in vitro by simulating single-leg stance phase. Rigidity of the whole proximal femur and the strain value at the juncture of femoral head and neck under 0,500N, 1000N load … were evaluated , until the femoral neck fracture. Results：The intensity and the beating capacity of femoral neck were found to be smaller in the necrosis of the femoral head＇s weight bearing region than in the non-weight beating region. The groups of 10% and 20% all have this tendency. The difference between the two is 17%, and there is a remarkable statistical difference（P〈0.001）. Conclusions ： The region of femoral head necrosis influences the beating capacity and the intensity of femoral neck. If the femoral head necrosis of femoral head＇s weight bearing region is up to 20%. The hip resurfacing shonld be choosen cautiously, because the femoral neck fracture is easy to occur.