Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T02:30:39.512Z Has data issue: false hasContentIssue false

Wear Evaluation of Ultra High Molecular Weight Polyethylene Using Pin-On-Flat and Hip Simulation Techniques

Published online by Cambridge University Press:  21 February 2011

David W. Schroeder
Affiliation:
Biomet, Inc., Airport Industrial Park, Warsaw, Indiana 46580
Joel C. Higgins
Affiliation:
Biomet, Inc., Airport Industrial Park, Warsaw, Indiana 46580
Get access

Abstract

Reduction of wear and wear debris is one of the most important areas of research presently in the field of orthopedic devices. It is speculated that wear debris is one of the contributing factors in the cascade of events that lead to osteolysis. In this regard it is very important to be able to evaluate in vitro the wear of UHMWPE produced by various manufacturing methods. Presently the three most common methods of wear testing are: pin-on-flat, pin-on-disk, and hip simulator.

Wear evaluation was performed on gamma irradiated UHMWPE that was manufactured by three different processes: extrusion, direct compression molding, and isostatic compression molding. The wear evaluation consisted of pin-on-flat and hip simulator testing.

omparison of the results from these two different types of tests show that the two tests would rank the wear resistance of the UHMWPE in the same order. However, there is a variation in the difference of the wear rates between the two tests. The pin-on-flat results show that the direct and isostatic compression molded material had approximately 50% less wear than the extruded material whereas the hip simulator results show that the isostatic compression molded material had 16% less wear than the extruded material. The difference in the results of these two tests are the effects of a combination of factors including the mechanical and material properties of the UHN4WPE, modes of wear that are active, the state of stress (constant vs. cyclic) in the specimens, third body contamination of the lubricant, bacterial degradation of the bovine serum lubricant, etc. Both tests are very important and necessary in the evaluation of wear of orthopedic materials.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Bankston, A.B., Keating, E.M., Ranawat, C., Faris, P.M., and Ritter, M.A., The comparison of poolyethylene wear in machined vs molded polyethylene, presented at UCLA Hip and Knee Meeting, October 1992.Google Scholar
2. Jensen, R.E., Collier, J.P., Mayor, M.B., and Surprenant, V.A., The role of polyethylene uniformity and patient characteristics in the wear of tibial knee components, presented at Implant Retrieval Symposium of the Society for Biomaterials, St. Charles, IL, September 17–20, 1992.Google Scholar
3. Knutson, K., Lewold, S., Lidgren, L., and Robertson, O., The Swedish Knee Arthroplasty Project: A nation-wide multicenter study of 34, 000 cases 19 75–1992 presented at American Academy of Orthopedic Surgeons, New Orleans, 1994.Google Scholar
4. Higgins, J.C., and Schroeder, D.W., Using isostatic pressing techniques to mold ultra high molecular weight polyethylene, presented at the 1995 MRS Spring Meeting, San Francisco, CA.Google Scholar
5. Hutchings, I.M. Tribology: Friction and Wear of Engineering Materials, (CRC Press, 1992), p. 125.Google Scholar