title: Corrosion of Metal Modular Cup Liners.
abstract: Numerous studies have reported on corrosion at the modular head taper, however less is known about the interface between the metal shell and liner of modular cups. This study examined the backside of a series of metal modular cup liners of two designs (DePuy Pinnacle and Smith & Nephew R3), retrieved from 67 patients. Visual inspection found evidence of corrosion in virtually all liners, with the engaging rim surface significantly more corroded than the polar regions (P<0.001). EDX confirmed that black surface deposits were chromium rich corrosion debris, while SEM analysis revealed considerable pitting in the vicinity of the black debris. The R3 liners were significantly more corroded that the Pinnacles (P<0.001); this may help to explain the higher revision rates of this design.
authors.affiliation: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: Harry S
authors.initials: HS
authors.lastname: Hothi
authors.affiliation: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: Kevin
authors.initials: K
authors.lastname: Ilo
authors.affiliation: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Whittaker
authors.affiliation: The Coxa Hospital for Joint Replacement, Tampere, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Eskelinen
authors.affiliation: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Skinner
authors.affiliation: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: Alister J
authors.initials: AJ
authors.lastname: Hart
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D002858:Chromium Alloys; D003343:Corrosion; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008670:Metals; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010384:Pelvic Bones / Q000648:ultrastructure; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation / Q000295:instrumentation*
chemical_list: D002858:Chromium Alloys; D008670:Metals
keywords: corrosion; liners; metal-on-metal; modular cup; retrieval