A novel tester to examine micro-abrasion of materials in oscillating sliding contact-The case study of a total knee replacement biomaterial

Wear of metallic biomaterials is critical in controlling and determining the long-term clinical performance of total joint replacements. Apart of reduced biomaterial's life span by wear, debris can cause hazardous inflammation and damage to the bone supporting the implant. The micro-abrasion tester is broadly used to evaluate wear resistance of biomaterials by the effect of hard debris interacting at the sliding interface. However, this tester is only capable to reproduce micro-abrasion in unidirectional sliding, contrary to that occurring in actual knee joints where sliding is oscillatory. So, micro-abrasion testing under oscillating sliding would be more realistic for this kind of biomedical applications since different sliding motion can promote dissimilar microabrasion mechanisms and wear rates. Hence, this paper presents a novel micro-abrasion tester able to reproduce both unidirectional and oscillating sliding modes. To illustrate the methodology using the tester, an ASTMF1537 CoCrMo alloy against an AISI 52100 steel countersurface was tested under unidirectional and oscillating sliding modes under rolling and grooving abrasion at different loads and sliding distances. The results obtained suggest similar wear rates and patterns for rolling abrasion but different for grooving for both sliding modes. Acceptable reproducibility, accuracy and versatility for micro-abrasion testing under different sliding modes were accomplished with this novel tester.

Automated summary

Wear of metallic biomaterials plays a critical role in determining the long-term clinical performance of total joint replacements. Micro-abrasion testing under different sliding modes is essential for evaluating wear resistance in biomedical applications.