title: Risk factors for revision within 10 years of total knee arthroplasty.
abstract: BACKGROUND
  An in-depth understanding of risk factors for revision TKA is needed to minimize the burden of revision surgery. Previous studies indicate that hospital and community characteristics may influence outcomes after TKA, but a detailed investigation in a diverse population is warranted to identify opportunities for quality improvement.
  
  
  OBJECTIVE
  We asked: (1) What is the frequency of revision TKA within 10 years of primary arthroplasty? (2) Which patient demographic factors are associated with revision within 10 years of TKA? (3) Which community and institutional characteristics are associated with revision within 10 years of TKA?
  
  
  METHODS
  We identified 301,955 patients who underwent primary TKAs in New York or California from 1997 to 2005 from statewide databases. Identifier codes were used to determine whether they underwent revision TKA. Patient, community, and hospital characteristics were analyzed using multivariable regression modeling to determine predictors for revision.
  
  
  RESULTS
  The frequency of revision was 4.0% at 5 years after the index arthroplasty and 8.9% at 9-years. Patients between 50 and 75 years old had a lower risk of revision than patients younger than 50 years (hazard ratio [HR], 0.47; 95% CI, 0.44, 0.50). Black patients were at increased risk for needing revision surgery (HR, 1.39; 95% CI, 1.29, 1.49) after adjustment for insurance type, poverty level, and education. Women (HR, 0.82; 95% CI, 0.79, 0.86) and Medicare recipients (HR, 0.82; 95% CI, 0.79, 0.86) were less likely to undergo revision surgery, whereas those from the most educated (HR, 1.09; 95% CI, 1.02, 1.16) and the poorest communities (HR, 1.08; 95% CI, 1.01, 1.15) had modest increases in risk of revision. Mid-volume hospitals (200-400 annual cases) had a reduction of early revision (HR, 0.91; 95% CI, 0.83, 0.99) compared with those performing less than 200 cases annually, whereas higher-volume hospitals (greater than 400 cases) showed little effect compared with low-volume hospitals.
  
  
  CONCLUSIONS
  Patient, community, and institutional characteristics affect the risk for revision within 10 years of index TKA. These data can be used to develop process improvement and implant surveillance strategies among high-risk patients.
  
  
  METHODS
  Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Dy
authors.forename: Robert G
authors.initials: RG
authors.lastname: Marx
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Bozic
authors.forename: Ting Jung
authors.initials: TJ
authors.lastname: Pan
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Padgett
authors.forename: Stephen
authors.initials: S
authors.lastname: Lyman
mesh_terms: D000367:Age Factors; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001696:Biomechanical Phenomena; D002140:California / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D061847:Hospitals, High-Volume; D061846:Hospitals, Low-Volume; D006801:Humans; D053208:Kaplan-Meier Estimate; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009518:New York / Q000453:epidemiology; D011183:Postoperative Complications / Q000601:surgery*; D016016:Proportional Hazards Models; D012086:Reoperation; D012307:Risk Factors; D012737:Sex Factors; D012959:Socioeconomic Factors; D013997:Time Factors