Wear performance of hip joint replacement

• Main Author: See, Ya-Pei.
• Other Authors: Liu Erjia
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering::Surgical assistive technology
• Online Access: http://hdl.handle.net/10356/53598
• Institution: Nanyang Technological University

There is an increasing demand of total hip arthroplasty (THA) surgeries worldwide and metal-on-polymer (MOP) artificial hip joint is most widely used for THA nowadays. However, wear particles from the materials remain the highest concern as they lead to joint loosening. Although studies have constantly been done to improve the wear performance, limited research was reported based on a ball-on-disc experimental setup. Surface modification to reduce wear was also not widely studied. This project aims to compare the wear performance of Ti-6Al-4V and Co-Cr-Mo alloy ball heads and study the effect of the dimple arrangement on the ball surfaces on the wear behaviour of both ball heads and UHMWPE discs. For material comparison, the two alloy balls were used as the upper sample and rubbed against a UHMWPE disc. As for the effect of dimple arrangement, the Ti-6Al-4V ball heads without dimples and with dimples patterned in multiples of 4 and 6 were tested against a concave shaped UHMWPE surface. It was found that the Co-Cr-Mo ball head produced less wear and lower coefficient of friction (COF), while the Ti-6Al-4V ball head without dimples had the lowest wear volume followed by the ball heads having dimples in multiples of 6, and finally by the heads having dimples in multiples of 4.