Xiao-Hong Wang1, Hui Li2, Xiang Dong2, Feng Zhao3, Cheng-Kung Cheng4. 1. School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China. 2. Naton Institute of Medical Technology, Beijing 100095, China; Beijing Engineering Laboratory of Functional Medical Materials and Devices, Beijing Naton Technology Group Co. Ltd., Beijing 100082, China; Beijing Medical Implant Engineering Research Center, Beijing Naton Technology Group Co. Ltd., Beijing 100082, China. 3. School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China; Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China. 4. School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China; Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China. Electronic address: ckcheng2009@gmail.com.
Abstract
BACKGROUND: The wear properties of knee implants need to be thoroughly evaluated prior to clinical use to ensure implant longevity. ISO 14243-1:2009 and ASTM F3141-17 are the two standards typically used for evaluating wear, with the ISO standard being more common; ASTM F3141-17 was first released in 2015. The aim of this study is to compare differences between these two standards in terms of wearing on a knee prosthesis. METHODS: Using finite element analysis based on Archard's law, this study evaluated anterior-posterior and internal-external motion, contact area, contact force, contact stress, volumetric wear rate, wear depth, and wear distribution on the knee prosthesis. FINDINGS: The results show that simulations performed according to ASTM F3141 produced knee kinematics that were more similar to human gait. The maximum wear depth occurred on the medial side of the tibia. However, the region of peak contact stress did not always correspond with the region of the maximum wear depth, indicating that considering the contact stress alone is not sufficient for evaluating wear as the sliding distance also plays an important role. The resulting wear region from the ASTM F3141 simulation was smaller but deeper than the wear region from the simulation per ISO 14243-1. However, the volumetric wear rates were very similar, with 13.48-55.26 mm3/million for ASTM F3141 and 13.64-54.9 mm3/million for ISO 14243-1. INTERPRETATION: The resulting rate of wear is almost identical between ISO 14243-1 and ASTM F3141. However, there are differences in wear contours and wear depth.
BACKGROUND: The wear properties of knee implants need to be thoroughly evaluated prior to clinical use to ensure implant longevity. ISO 14243-1:2009 and ASTM F3141-17 are the two standards typically used for evaluating wear, with the ISO standard being more common; ASTM F3141-17 was first released in 2015. The aim of this study is to compare differences between these two standards in terms of wearing on a knee prosthesis. METHODS: Using finite element analysis based on Archard's law, this study evaluated anterior-posterior and internal-external motion, contact area, contact force, contact stress, volumetric wear rate, wear depth, and wear distribution on the knee prosthesis. FINDINGS: The results show that simulations performed according to ASTM F3141 produced knee kinematics that were more similar to human gait. The maximum wear depth occurred on the medial side of the tibia. However, the region of peak contact stress did not always correspond with the region of the maximum wear depth, indicating that considering the contact stress alone is not sufficient for evaluating wear as the sliding distance also plays an important role. The resulting wear region from the ASTM F3141 simulation was smaller but deeper than the wear region from the simulation per ISO 14243-1. However, the volumetric wear rates were very similar, with 13.48-55.26 mm3/million for ASTM F3141 and 13.64-54.9 mm3/million for ISO 14243-1. INTERPRETATION: The resulting rate of wear is almost identical between ISO 14243-1 and ASTM F3141. However, there are differences in wear contours and wear depth.