Materials testing protocol for small joint prostheses.
In this article, a protocol for the evaluation of new materials for small joint prostheses is introduced. The testing methods employed in the protocol were developed by reviewing reported clinical failure modes and conditions found in vivo. The methods developed quantitatively evaluates the fatigue, fatigue crack propagation, and wear resistance properties of materials. For this study, a silicone elastomer similar to Dow Corning Silastic HP100, a radiation stable polypropylene, and a copolymer of polypropylene and ethylene propylene-diene monomer (EPDM) are evaluated. None of the materials tested demonstrated the ideal properties that are sought in a self-hinging joint prostheses. The silicone elastomer had excellent wear properties; however, cracks quickly propagated, causing catastrophic failure when fatigued. Conversely, the copolymer showed excellent fatigue crack propagation resistance and less than favorable wear properties. The polypropylene did not perform well in any evaluation.
Savory
K M
KM
University of Utah School of Medicine, Orthopaedic Bioengineering Laboratory, Salt Lake City 84132.
Hutchinson
D T
DT
Bloebaum
R
R
D001672:Biocompatible Materials / Q000592:standards*; D017408:Guidelines as Topic; D006801:Humans; D007595:Joint Prosthesis; D011095:Polyethylenes; D011126:Polypropylenes; D011475:Prosthesis Failure; D012826:Silicone Elastomers; D013314:Stress, Mechanical; D013499:Surface Properties
D001672:Biocompatible Materials; D011095:Polyethylenes; D011126:Polypropylenes; D012826:Silicone Elastomers