title: A squeaky reputation: the problem may be design-dependent.
abstract: BACKGROUND
  Squeaking is reportedly a complication in patients having ceramic-on-ceramic total hip implants. The etiology remains unknown and multifactorial with recent studies suggesting a relationship between the audible squeak and implant design. When we evaluated our ceramic-on-ceramic cohort, we noticed squeaking primarily in patients receiving an acetabular system designed with an elevated titanium rim.
  
  
  OBJECTIVE
  We therefore (1) determined the incidence of squeaking among four different ceramic-on-ceramic bearing surfaces used for THA at our institution; (2) evaluated the association between different acetabular designs and the incidence of squeaking; and (3) assessed other potential variables associated with squeaking.
  
  
  METHODS
  We retrospectively reviewed 1507 patients having a ceramic-on-ceramic THA between 2002 and 2009; we separately analyzed those receiving an acetabular system with and without an elevated titanium rim. Data were collected through phone-administered questionnaires and retrospective reviews of patient charts for intraoperative findings, followup reports, demographic information, and radiographic findings.
  
  
  RESULTS
  Squeaking occurred in 92 of the 1507 patients (6%). All 92 patients with squeaking received an elevated rim design (1291 patients) or an incidence of 7% with that design. We found no association between squeaking and any other examined factors.
  
  
  CONCLUSIONS
  Our findings complement the theory from in vitro studies suggesting that neck impingement on the elevated titanium rim is the probable cause of the increased frequency of squeaking with this design.
authors.affiliation: The Rothman Institute of Orthopaedics at Thomas Jefferson University Hospital, 925 Chestnut Street, 5th Floor, Philadelphia, PA 19107, USA. research@rothmaninstitute.com
authors.forename: Javad
authors.initials: J
authors.lastname: Parvizi
authors.forename: Bahar
authors.initials: B
authors.lastname: Adeli
authors.forename: Justin C
authors.initials: JC
authors.lastname: Wong
authors.forename: Camilo
authors.initials: C
authors.lastname: Restrepo
authors.forename: Richard H
authors.initials: RH
authors.lastname: Rothman
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011474:Prosthesis Design; D011859:Radiography; D014481:United States / Q000453:epidemiology; D055815:Young Adult