title: Retrieval analysis of a failed TriboFit polycarbonate urethane acetabular buffer.
abstract: The purpose of this research was to determine the failure mechanisms and damage features of a TriboFit acetabular buffer implanted directly against a native, prepared acetabulum which was revised after 11months. Retrieval analyses were carried out via light microscopy, gravimetric wear assessment, and observer scoring of visible damage features on the buffer. The volume of material abraded from the backside of the buffer was estimated via three-dimensional reconstruction using a laser scanner. Scanning electron microscopy was used to confirm damage features and mechanisms. Severe abrasion to the backside of the buffer was the primary damage feature, while stippling damage was seen on the articular surface of the buffer. Material loss due to backside abrasion was approximated to be between 0.13360.085 g (gravimetric analyses) and 0.19360.053 g (three-dimensional reconstruction). Implantation of the TriboFit buffer against the patient's native acetabulum without a metal backing allowed for significant movement of the buffer against the bone, resulting in the abrasion seen on this implant. The stippling damage on the articular surface indicates an adhesive wear mechanism which exacerbates movement of the buffer against the acetabulum, thereby increasing backside abrasion.
authors.affiliation: The Royal Infirmary of Edinburgh, Edinburgh, UK leela.biant@luht.scot.nhs.uk.
authors.forename: Leela C
authors.initials: LC
authors.lastname: Biant
authors.affiliation: Orthopaedic Innovation Centre, Winnipeg, MB, Canada Concordia Joint Replacement Group, Winnipeg, MB, Canada.
authors.forename: Trevor C
authors.initials: TC
authors.lastname: Gascoyne
authors.affiliation: Concordia Joint Replacement Group, Winnipeg, MB, Canada.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Bohm
authors.affiliation: The Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Moran
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000368:Aged; D001672:Biocompatible Materials / Q000627:therapeutic use; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D011076:Polycarboxylate Cement / Q000627:therapeutic use; D011474:Prosthesis Design; D011475:Prosthesis Failure; D014520:Urethane / Q000627:therapeutic use
chemical_list: D001672:Biocompatible Materials; D011076:Polycarboxylate Cement; C005506:polycarbonate; D014520:Urethane
keywords: Hip prostheses; abrasive wear; biomaterials; joint prosthetics; polymers