Callaghan John J, Pedersen Douglas R, Johnston Richard C, Brown Thomas D
Department of Orthopaedic Surgery, University of Iowa College of Medicine, Iowa City 52242, USA.
Iowa Orthop J. 2003;23:1-12.
Complementary clinical and laboratory studies were performed to identify variables associated with polyethylene wear following total hip replacement, and to elucidate the mechanisms responsible for accelerated wear in the total hip arthroplasty construct. Observational cohort studies were performed using a prospective clinical database of more than 4000 consecutive primary total hip arthroplasties performed by a single surgeon, to identify wear-related variables. These variables included head size, acetabular/femoral component impingement, and third body debris. Novel digital edge detection techniques were developed and employed to accurately measure wear, and to determine the relationships of head size and third body debris to acceleration of wear. A novel sliding-distance-coupled finite element model was formulated and employed to examine the mechanisms responsible for wear. The long-term cohort studies demonstrated smaller head sizes to be associated with less wear. Third body debris generated from cable fretting was associated with an increase in wear, osteolysis, and acetabular loosening, especially with larger head sizes. The sliding-distance-coupled finite element model replicated the wear rates occurring in vitro and in vivo, demonstrating the importance of sliding distance on polyethylene wear following total hip arthroplasty. It also demonstrated substantial increases in wear associated with femoral head scratching from third body debris. Further extension of the finite element formulation demonstrated the potential for acetabular component rim damage from impingement wear, and the enhanced potential for third body ingress to the bearing surface with larger head sizes. Edge detection wear measurement techniques demonstrated that early wear rates were predictive of long-term wear rates. These complementary clinical and laboratory investigations have provided insight into 1) the significance of sliding distance and physiologic loci of motion as contributing factors in minimizing wear, 2) the deleterious effects of third body particulates in accelerating wear, 3) the potential for, and factors related to, impingement wear, and 4) the potential advantages and compromises related to the use of larger head sizes in the bearing surface construct.
开展了补充性临床和实验室研究，以确定与全髋关节置换术后聚乙烯磨损相关的变量，并阐明全髋关节置换结构中加速磨损的机制。利用一位外科医生连续进行的4000多例初次全髋关节置换术的前瞻性临床数据库进行观察性队列研究，以确定与磨损相关的变量。这些变量包括股骨头大小、髋臼/股骨组件撞击和第三体碎屑。开发并采用了新颖的数字边缘检测技术来准确测量磨损，并确定股骨头大小和第三体碎屑与磨损加速之间的关系。构建并采用了一种新颖的滑动距离耦合有限元模型来研究磨损机制。长期队列研究表明，较小的股骨头尺寸与较少的磨损相关。电缆微动产生的第三体碎屑与磨损增加、骨溶解和髋臼松动有关，尤其是在股骨头尺寸较大时。滑动距离耦合有限元模型复制了体外和体内发生的磨损率，证明了滑动距离对全髋关节置换术后聚乙烯磨损的重要性。它还表明，第三体碎屑导致的股骨头刮擦会使磨损大幅增加。有限元公式的进一步扩展表明，撞击磨损可能导致髋臼组件边缘损伤，并且股骨头尺寸较大时，第三体进入轴承表面的可能性增加。边缘检测磨损测量技术表明，早期磨损率可预测长期磨损率。这些补充性临床和实验室研究为以下方面提供了见解：1）滑动距离和生理运动轨迹作为减少磨损的促成因素的重要性；2）第三体颗粒在加速磨损方面的有害影响；3）撞击磨损的可能性及相关因素；4）在轴承表面结构中使用较大股骨头尺寸的潜在优势和折衷。
