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Effect of slide track shape on the wear of ultra‐high molecular weight polyethylene in a pin‐on‐disk wear simulation of total hip prosthesis
Author(s) -
Saikko Vesa,
Calonius Olof,
Keränen Jaakko
Publication year - 2004
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.20043
Subject(s) - track (disk drive) , polyethylene , materials science , prosthesis , periprosthetic , relative motion , total hip replacement , composite material , biomedical engineering , orthodontics , mechanical engineering , engineering , medicine , surgery , mechanics , physics , arthroplasty
Prosthetic joints appear to show a strong relationship between the type of relative motion and wear, requiring careful consideration in the design of wear simulators. This relationship was studied with a 12‐station pin‐on‐disk device, specifically adapted for the wear simulation of prosthetic hip joints. Each station had a unique motion, characterized by the so‐called slide track, the track of the pin on the disk. The slide track shapes included 10 ellipses, their aspect ratio (AR) varying from 1.1 to 11.0, and a circle and a straight line as extreme cases. Hence for the first time in hip wear simulation, the motion was systematically varied over a wide range. Conventional UHMWPE pins were tested against polished CoCr disks in diluted calf serum three times for 3 million cycles. Below the AR value of 5.5, the polyethylene wear factor and wear mechanisms agreed with clinical observations. Above this value, the wear factor decreased to unrealistically low values, and the wear surface topography differed from that of retrieved acetabular cups. The wear particles, however, were similar to those isolated from periprosthetic tissues, irrespective of the AR value. In conclusion, it is recommended that the AR value be kept well below the critical point of 5.5. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 69B: 141–148, 2004