title: Pseudotumour formation due to tribocorrosion at the taper interface of large diameter metal on polymer modular total hip replacements.
abstract: We present an in-depth failure analysis of two large diameter bearing metal-on-polymer (MoP) modular total hip replacements, which have required revision surgery due to pseudotumour formation. The failure analysis showed a discrete pattern of material loss from the distal end of the head taper/stem trunnion interface. We postulate that the use of a proximal contacting taper design had provided insufficient mechanical locking between the head and the stem, enabling the head to toggle on the trunnion. In addition, the difference in angle between the taper and the trunnion formed a crevice between the two components. Through a combination of crevice environment, mechanically assisted corrosion, mechanical wear and erosion; debris and metal-ions have been released resulting in the adverse local tissue reactions (ALTR).
authors.affiliation: National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Cook
authors.forename: Benjamin J R F
authors.initials: BJ
authors.lastname: Bolland
authors.forename: Julian A
authors.initials: JA
authors.lastname: Wharton
authors.forename: Simon
authors.initials: S
authors.lastname: Tilley
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Latham
authors.forename: Robert J K
authors.initials: RJ
authors.lastname: Wood
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D019544:Equipment Failure Analysis; D005260:Female; D006104:Granuloma, Plasma Cell / Q000209:etiology*; D006621:Hip Joint / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008670:Metals / Q000009:adverse effects*; D011108:Polymers / Q000009:adverse effects*; D012086:Reoperation
chemical_list: D008670:Metals; D011108:Polymers
keywords: corrosion; fretting; hip; pseudotumour; taper