title: Acetabular loosening using an extended offset polyethylene liner.
abstract: The use of extended offset femoral components and acetabular liners helps restore preoperative offset during hip arthroplasty. We report a relatively high acetabular component aseptic loosening rate with the use of offset polyethylene liners. We reviewed 1919 primary and 346 revision total hip arthroplasties (THAs). A 7-mm offset acetabular liner was used in 120 of the primary and 100 of the revision THAs. The aseptic loosening rate in the primary THA group was 0.12% in the standard offset and 4.2% in the extended offset groups at a minimum of 2 years (mean, 3.6 years; range, 2-9 years) followup. The aseptic loosening rate in the revision group was 1.7% in the standard and 7% in the extended offset groups at a mean of 4 years (range, 2-9 years) followup. Although extended offset acetabular liners help restore hip offset, torsional force applied to the implant-bone interface may have a detrimental effect on fixation. We found a relatively high failure rate in our primary and revision acetabular components used with an offset liner.
  
  
  METHODS
  Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: New Mexico Center for Joint Replacement Surgery, New Mexico Orthopaedics, Albuquerque, NM 87106, USA. archibeckmj@nmortho.net
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Archibeck
authors.forename: Tamara
authors.initials: T
authors.lastname: Cummins
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Junick
authors.forename: Richard E
authors.initials: RE
authors.lastname: White
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation / Q000706:statistics & numerical data; D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D020959:Polyethylene
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