TOTAL SURGICAL REPLACEMENT OF THE HUMAN HIP JOINT

描述(改编自申请者摘要)：本建议书 非骨水泥术后股骨适应性骨重建的研究 骨水泥型全髋关节置换术。临床上，超过50%的 髋关节置换术后假体周围的骨量可能会丢失。这个 与健康相关的实际目标是延长种植者的存活期和 通过最大限度地减少骨丢失，促进潜在的翻修手术 应力遮挡，骨的初始机械载荷减少 股骨近端由于通过假体的载荷转移。中环 假说是(在没有与降解相关的骨溶解的情况下 植入物)应力屏蔽代表了最重要的独立 患者、植入物和患者通过的可变或最终共同途径 技术因素在以下骨丢失中占很大比例 全髋关节置换术。如果这一论点是正确的，那么年龄等因素 和种植体粘结的来源(例如，骨向内生长与水泥固定相比) 在适应过程中发挥作用，主要是通过机械中介 小路。申请者建议通过检验来检验他们的假设。 它的三个影响：(1)压力屏蔽的个体差异 解释了股骨骨丢失中很大比例的个体差异 髋关节置换术后；(Ii)骨丢失与 骨骼成熟的幼年和老年动物的应激保护 非骨水泥髋关节置换术，即使实际的骨丢失量可能 随着年龄的变化而变化；以及(Iii)骨丢失与 骨水泥型和非骨水泥型全髋关节置换术中的应力遮挡。 对应力屏蔽的单独评估将基于 犬模型的动物专用有限元建模。这些估计 将与假体周围骨量变化的测量相关 都是用同样的动物做的。这样，被依赖项中的实际差异 变量(骨量变化)，由独立变量中的方差解释 变量(应力屏蔽)和关系的性质(线性或 非线性)，将被确定。动物模型的使用允许其他原因 很大程度上消除了骨丢失，从而允许 应力屏蔽要有明确的定义。

DESCRIPTION (Adapted from the Applicant's Abstract): This proposal is concerned with adaptive bone remodeling of the femur following cementless and cemented total hip arthroplasty. Clinically, over 50% of the periprosthetic bone mass can be lost following hip arthroplasty. The practical health-related goal is to prolong implant survivorship and facilitate potential revision surgery by minimizing bone loss attributed to stress-shielding, the initial reduction in mechanical loading of the bone in the proximal femur due to load transfer through the prosthesis. The central hypothesis is that (in the absence of osteolysis related to degradation of the implant) stress-shielding represents the most important independent variable or "final common pathway" through which patient, implant and technical factors account for a large proportion of the bone loss following total hip arthroplasty. If this thesis is correct, then factors such as age and source of implant bonding (e.g., bone ingrowth versus cement fixation) play a role in the adaptive process, largely through mechanically-mediated pathways. The applicants propose to test their hypothesis by examining three of its implications: (i) individual variation in stress-shielding explains a large proportion of the individual variation in femoral bone loss following hip replacement; (ii) bone loss has the same relationship to stress-shielding in skeletally mature young and old animals following cementless hip replacement, even though the actual amount of bone loss may vary as a function of age; and (iii) bone loss has the same relationship to stress-shielding in cemented and cementless total hip arthroplasty. Individual estimates of stress-shielding will be made based on animal-specific finite element modeling of a canine model. These estimates will be correlated with measurements of change in periprosthetic bone mass made in the same animals. In this way, the actual variance in the dependent variable (change in bone mass), explained by variance in the independent variable (stress-shielding) and the nature of the relationship (linear or nonlinear), will be determined. Use of an animal model allows other causes of bone loss to be largely eliminated, thus permitting the effects of stress-shielding to be clearly defined.