Date of Award
12-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Bioengineering
Committee Chair/Advisor
Dr. Jeremy L. Gilbert
Committee Member
Dr. John DesJardins
Committee Member
Dr. Martine LaBerge
Committee Member
Dr. Jeremy Mercuri
Abstract
Cobalt Chrome Molybdenum (CoCrMo) remains a popular material choice for femoral condyles in total knee arthroplasty and for acetabular liners in dual mobility total hip designs. CoCrMo has been phased out of conventional THA designs due to its correlation with adverse effects such as ALTR and ALVAL. It is less understood if the mechanisms (i.e. abrasive wear to the surface of the implant) that release metal ions into the surrounding tissue occur at similar rates as seen in conventional THA. Additionally, it is unknown what effect the secondary damage modes such as electrocautery damage and adhesive wear have on these devices. In this thesis we (1) create a semi-quantitative wear score for explanted CoCrMo femoral condyles; (2) determine if the wear score correlates with ion release into the periprosthetic tissue; (3) identify secondary damage modes that may be contributing to metal ion release; (4) evaluate the performance of dual mobility hip acetabular cup-liner constructs during cyclic loading testing while also evaluating the effect of implant size and finally; (5) determine if a low power electron beam coating can be applied to CoCrMo and other passive biomaterial surfaces and act as a wear resistant coating. We show a clear relationship between our semi-quantitative wear score and the ion concentration in the periprosthetic tissue. As the severity of the wear to the implant increases, so do the Co, Cr, and Mo levels in the surrounding tissue. Further, we established that damage modes such as electrocautery damage and material transfer from the backside of the tibial component onto the posterior condyle of the femoral component are more prevalent than originally thought. These damage modes, along with migration of alumina from grit blasted tibial components, allow for third body wear particles to enter the implant system during in vivo use. Next, we found that after undergoing 3,000,000 cycles, implant size had no effect on the degradation of dual mobility hip acetabular cup-liner constructs. Moreover, the testing showed that there were low levels of wear and ion release regardless of implant size. Last, we found that low power electron beam coatings could be systematically applied to the surface of passive biomaterials. These coatings were more wear resistant than the underlying metal surface. In conclusion, these results indicate that many of the same mechanisms that result in cobalt release in conventional hip designs are occurring in commonly used devices in TKA and dual mobility THA designs.
Recommended Citation
Kurtz, Peter William, "Degradation of Cobalt Chrome Molybdenum Hip And Knee Implants in Vivo and in Vitro" (2025). All Dissertations. 4178.
https://open.clemson.edu/all_dissertations/4178
Author ORCID Identifier
https://orcid.org/0009-0000-8216-8509