title: Risk of subsequent revision after primary and revision total joint arthroplasty.
abstract: BACKGROUND
  Revision is technically more demanding than primary total joint arthroplasty (TJA) and requires more extensive use of resources. Understanding the relative risk of rerevision and risk factors can help identify patients at high risk who may require closer postsurgical care.
  
  
  OBJECTIVE
  We therefore evaluated the risk of subsequent revision after primary and revision TJA in the elderly (65 years or older) patient population and identified corresponding patient risk factors.
  
  
  METHODS
  Using the 5% Medicare claims data set (1997-2006), we identified a total of 35,746 patients undergoing primary THA and 72,913 undergoing primary TKA; of these, 1205 who had THAs and 1599 who had TKAs underwent initial revision surgery. The rerevision rate after primary and revision TJAs was analyzed by the Kaplan-Meier method. The relative risk of revision surgery for primary and revision TJAs was compared using hazard ratio analysis.
  
  
  RESULTS
  The 5-year survival probabilities were 95.9%, 97.2%, 81.0%, and 87.4% for primary THA and TKA and revision THA and TKA, respectively. Patients with revision arthroplasty were five to six times more likely to undergo rerevision (adjusted relative risk, 4.89 for THA; 5.71 for TKA) compared with patients with primary arthroplasty. Age and comorbidities were associated with initial revision after primary THA and TKA.
  
  
  CONCLUSIONS
  Patients should undergo stringent preoperative screening for preexisting health conditions and careful patient management and followup postoperatively so as to minimize the risk of an initial revision, which otherwise could lead to a significantly greater likelihood of subsequent rerevisions.
authors.affiliation: Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA. kong@exponent.com
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Ong
authors.forename: Edmund
authors.initials: E
authors.lastname: Lau
authors.forename: Jeremy
authors.initials: J
authors.lastname: Suggs
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.forename: Michael T
authors.initials: MT
authors.lastname: Manley
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015897:Comorbidity; D019992:Databases as Topic; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D006278:Medicare; D018579:Patient Selection; D016016:Proportional Hazards Models; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States