Caravia L, Dowson D, Fisher J, Jobbins B
Department of Mechanical Engineering, University of Leeds.
Proc Inst Mech Eng H. 1990;204(1):65-70. doi: 10.1243/PIME_PROC_1990_204_230_02.
Studies of explanted hip prostheses have shown high wear rates of ultra-high molecular weight polyethylene (UHMWPE) acetabular cups and roughening of the surface of the metallic femoral head. Bone and bone cement particles have also been found in the articulating surfaces of some joints. It has been proposed that bone or bone cement particles may cause scratching and deterioration in the surface finish of metallic femoral heads, thus producing increased wear rates and excessive amounts of wear debris. Sliding wear tests of UHMWPE pins on stainless steel have been performed with particles of different types of bone and bone cement added. Damage to the stainless steel counterface and the motion of particles through the interface have been studied. Particles of bone cement with zirconium and barium sulphate additives and particles of cortical bone scratched the stainless steel counterface. The cement particles with zirconium additive produced significantly greater surface damage. The number of particles entering the contact and embedding in the UHMWPE pin was dependent on particle size and geometry, surface roughness and contact stress. Particles are likely to cause surface roughening and increased wear rates in artificial joints.
对取出的髋关节假体的研究表明，超高分子量聚乙烯（UHMWPE）髋臼杯的磨损率很高，金属股骨头表面出现粗糙化。在一些关节的关节表面还发现了骨和骨水泥颗粒。有人提出，骨或骨水泥颗粒可能会导致金属股骨头表面光洁度出现划痕并恶化，从而导致磨损率增加和产生过量的磨损碎屑。已进行了在不锈钢上添加不同类型的骨和骨水泥颗粒的UHMWPE销的滑动磨损试验。研究了不锈钢配对表面的损伤以及颗粒通过界面的运动情况。添加了锆和硫酸钡的骨水泥颗粒以及皮质骨颗粒划伤了不锈钢配对表面。添加锆的水泥颗粒造成的表面损伤明显更大。进入接触并嵌入UHMWPE销中的颗粒数量取决于颗粒大小和几何形状、表面粗糙度和接触应力。颗粒很可能会导致人工关节表面粗糙化并提高磨损率。
