title: Incomplete seating of the liner with the Trident acetabular system: a cause for concern?
abstract: We reviewed the initial post-operative radiographs of the Trident acetabulum and identified a problem with seating of the metal-backed ceramic liner. We identified 117 hips in 113 patients who had undergone primary total hip replacement using the Trident shell with a metal-backed alumina liner. Of these, 19 (16.4%) were noted to have incomplete seating of the liner, as judged by plain anteroposterior and lateral radiographs. One case of complete liner dissociation necessitating early revision was not included in the prevalence figures. One mis-seated liner was revised in the early post-operative period and two that were initially incompletely seated were found on follow-up radiographs to have become correctly seated. There may be technical issues with regard to the implanting of this prosthesis of which surgeons should be aware. However, there is the distinct possibility that the Trident shell deforms upon implantation, thereby preventing complete seating of the liner.
authors.affiliation: Portsmouth Hospitals NHS Trust, Queen Alexandra Hospital, Southwick Hill Road, Cosham, Portsmouth PO6 3LY, UK. andrew.langdown@porthosp.nhs.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Langdown
authors.forename: R J
authors.initials: RJ
authors.lastname: Pickard
authors.forename: C M
authors.initials: CM
authors.lastname: Hobbs
authors.forename: H J
authors.initials: HJ
authors.lastname: Clarke
authors.forename: D J N
authors.initials: DJ
authors.lastname: Dalton
authors.forename: M L
authors.initials: ML
authors.lastname: Grover
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000601:surgery; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D015331:Cohort Studies; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D007592:Joint Diseases / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation