title: Component size mismatch of metal on metal hip arthroplasty: an avoidable never event.
abstract: Size mismatch of components used in total hip arthroplasty is a serious, preventable patient safety incident of unknown prevalence as many cases are not detected. Component size mismatch was found in 11 cases (0.9%) at our retrieval centre. All cases of mismatch were not detected on plain radiograph during routine clinical follow up and blood metal ion levels were elevated above the MHRA action level of 7 ppb. Root cause analysis identified manufacturer, hospital and surgeon factors that need to be addressed to reduce the incidence of this avoidable clinical problem. Retrieval analysis is the only method of confirming size mismatch and is likely to be under-represented in National Joint Registries that record the indication for revision at the time of revision.
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: Institute of Orthopaedics and Musculoskeletal Science, University College London and the Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Hexter
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: Anna
authors.initials: A
authors.lastname: Panagiotidou
authors.affiliation: The Centre for Precision Technologies, University of Huddersfield, United Kingdom.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Bills
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: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000009:adverse effects* / Q000706:statistics & numerical data; D008670:Metals; D008875:Middle Aged; D009929:Organ Size; D061214:Patient Safety; D015995:Prevalence; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D011859:Radiography; D012042:Registries / Q000706:statistics & numerical data; D012086:Reoperation; D012307:Risk Factors
chemical_list: D008670:Metals
keywords: hip; metal-on-metal; retrieval; size mismatch; wear