title: Wear and creep behavior of total knee implants undergoing wear testing.
abstract: We sought to determine what dimensional changes occurred from wear testing of a total knee implant, as well as any changes within the polyethylene subsurface. Three fixed bearing implants underwent wear simulator testing to 6.1 million cycles. Gravimetric analysis and micro-CT scans were performed pre-test, mid-test, and post-test. Wear volume and surface deviations were greater during 0-3.2 million cycles (91 ± 12mm(3)) than from 3.2 to 6.1 million cycles (52 ± 18mm(3)). Deviations (wear and creep) occurred across all surfaces of the tibial inserts, including the articular surface, backside surface, sides, and locking mechanism. No subsurface changes were found. The micro-CT results were a useful adjunct to gravimetric analysis, defining the dimensional changes that occurred with testing and ruling out subsurface fatigue.
authors.affiliation: Division of Orthopaedic Surgery, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Teeter
authors.affiliation: Smith & Nephew, Memphis, Tennessee.
authors.forename: Amit
authors.initials: A
authors.lastname: Parikh
authors.affiliation: Smith & Nephew, Memphis, Tennessee.
authors.forename: Marc
authors.initials: M
authors.lastname: Taylor
authors.affiliation: Smith & Nephew, Memphis, Tennessee.
authors.forename: Jeff
authors.initials: J
authors.lastname: Sprague
authors.affiliation: Division of Orthopaedic Surgery, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Naudie
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D001672:Biocompatible Materials; D019544:Equipment Failure Analysis; D007720:Knee Prosthesis; D008422:Materials Testing; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013977:Tibia; D014800:Vitallium; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D014800:Vitallium; D020959:Polyethylene
keywords: creep; micro-CT; subsurface fatigue; total knee arthroplasty; wear simulator