Title: Hip implant stem interfacial motion, a finite element analysis

Authors: Mbulelo T. Makola, Tarun Goswami

Addresses: Department of Biomedical Engineering, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435-0001, USA. ' Department of Biomedical Engineering, Department Orthopedic Surgery and Sports Medic, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435-0001, USA

Abstract: A key factor in press fit hip implant fixation is the amount of interfacial motion between implant stem and the femur. A finite element analysis of hip implant stem designs was performed to determine the effect on stem interfacial motion. Implants of distinct cross section and stem profile were analysed. Implant material property effects were studied by analysing cobalt chromium (CoCr), stainless steel (SS316L), and titanium alloy (Ti 6Al-4V) implants. Each implant was subjected to a static loading simulating the weight of an average US male (189 lb) taking a step forward. Study results showed that implant cross section played a role in interfacial motion amounts. Ti 6Al-4V showed the greatest difference in implant interfacial motion as compared to SS316L and CoCr. Continued design and development of implant stems resistant to interfacial motion is needed.

Keywords: hip arthroplasty; hip implant; implant stems; total hip replacement; cement less; interfacial motion; micromotion; implant fixation; implant loosening; finite element analysis; FEA; press fit implants; femur; cobalt chromium implants; stainless steel implants; titanium alloy implants; titanium alloys.

DOI: 10.1504/IJECB.2011.039946

International Journal of Experimental and Computational Biomechanics, 2011 Vol.1 No.4, pp.343 - 358

Published online: 30 Dec 2014 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article