title: Causes of failure of ceramic-on-ceramic and metal-on-metal hip arthroplasties.
abstract: BACKGROUND
  Few large series of hard bearing surfaces have reported on reasons for early failure. A number of unique mechanisms of failure, including fracture, squeaking, and adverse tissue reactions, have been reported with these hard bearing surfaces. However, the incidence varies among the published studies.
  
  
  OBJECTIVE
  To confirm the incidences, we identified the etiologies of early failures of hard-on-hard bearing surfaces for ceramic-on-ceramic and metal-on-metal THAs.
  
  
  METHODS
  We retrospectively reviewed records of 2907 THAs with hard-on-hard bearing surfaces implanted between 1996 and 2009; 1697 (58%) had ceramic-on-ceramic and 1210 (42%) had metal-on-metal bearing surfaces. We recorded bearing-related complications and compared them to nonspecific reasons for revision THA. The minimum followup of the ceramic-on-ceramic and metal-on-metal cohorts was 6 months (mean, 48 months; range, 6-97 months) and 24 months (mean, 60 months; range, 24-178 months), respectively.
  
  
  RESULTS
  The overall revision rate for ceramic-on-ceramic THA was 2.2% (38 of 1697), with aseptic loosening accounting for 55% of revisions (femur or acetabulum). The bearing accounted for 13% of the revisions in the ceramic-on-ceramic THA cohort. The overall metal-on-metal revision rate was 5.4% (65 of 1210), 17 involving adverse tissue reactions related to the metal-on-metal bearing surface (17 of 1210, 1.4% of cases; 17 of 65, 26% of revisions).
  
  
  CONCLUSIONS
  Twenty-six percent of the revisions from metal-on-metal and 13% of ceramic-on ceramic were bearing related. The overall short- to medium-term revision rate was 2.2% and 5.4% for ceramic-on-ceramic and metal-on-metal, respectively. The most common etiology of failure was loosening of the femoral or acetabular components.
  
  
  METHODS
  Level IV, therapeutic study. See the Guidelines for Authors for a complete description of level of evidence.
authors: Rothman Institute at Thomas Jefferson University, Philadelphia, PA, USA.
authors: Manny
authors: M
authors: Porat
authors: Javad
authors: J
authors: Parvizi
authors: Peter F
authors: PF
authors: Sharkey
authors: Keith R
authors: KR
authors: Berend
authors: Adolph V
authors: AV
authors: Lombardi
authors: Robert L
authors: RL
authors: Barrack
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D002516:Ceramics; D005260:Female; D006621:Hip Joint / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012044:Regression Analysis; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
chemical_list: D008670:Metals