title: In vivo oxidation contributes to delamination but not pitting in polyethylene components for total knee arthroplasty.
abstract: The aim of this study was to better understand how in vivo oxidation contributes to fatigue damage in total knee arthroplasty (TKA). A total of 119 tibial inserts were consecutively collected after revision surgery. Of the 119 polyethylene retrievals, 29 were gamma sterilized in air (historical), whereas the remaining 90 were gamma sterilized in nitrogen (conventional). Surface damage assessment and characterization of oxidation were performed on all the retrievals. Delamination was significantly more prevalent and extensive in the longer-term, highly oxidized, historical tibial inserts. Pitting damage, in contrast, seemed to be equally prevalent between both retrieval groups and was not correlated with in vivo oxidation. Our findings support our hypothesis that in vivo oxidation is a contributing factor to delamination, but not pitting, in TKA. Despite the lower oxidation displayed by conventional retrievals, this study provides strong evidence that delamination secondary to in vivo oxidation may occur during the second decade of implantation.
authors.affiliation: Implant Research Center, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Medel
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.forename: Javad
authors.initials: J
authors.lastname: Parvizi
authors.forename: Gregg R
authors.initials: GR
authors.lastname: Klein
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
authors.forename: Clare M
authors.initials: CM
authors.lastname: Rimnac
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D015331:Cohort Studies; D020878:Device Removal; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D005720:Gamma Rays; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D009584:Nitrogen; D010084:Oxidation-Reduction; D011095:Polyethylenes; D011475:Prosthesis Failure / Q000209:etiology*; D012086:Reoperation; D012189:Retrospective Studies; D013242:Sterilization / Q000379:methods; D055815:Young Adult
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D009584:Nitrogen