title: Perioperative morbidity and mortality of same-day bilateral TKAs: incidence and risk factors.
abstract: BACKGROUND
  Controversy persists regarding the safety of same-day bilateral TKAs, and indications for same-day versus staged bilateral surgery need to be clarified.
  
  
  OBJECTIVE
  We compared the (1) 30-day mortality, (2) rates of in-hospital complications, (3) in-hospital charges, and (4) risk factors for complications among patients undergoing same-day and staged bilateral TKAs at two separate admissions within 1 year either less than 3 months apart (staged 0-3) or more than 3 months apart (staged 3-12) at an institution where same-day bilateral TKAs were discouraged in patients with more severe medical comorbidities.
  
  
  METHODS
  We analyzed institutional data from 3960 same-day, 172 staged 0-3, and 1533 staged 3-12 bilateral TKAs performed between 1998 and 2011. Patient demographics, comorbidities, and 30-day mortality were tabulated. Same-day patients were younger and healthier. Outcomes of interest included complications, blood transfusions, transfer to rehabilitation, and in-hospital charges. Regression models were conducted to identify independent risk factors for major morbidity or mortality.
  
  
  RESULTS
  There were no differences in 30-day mortality among groups. The same-day group experienced more acute postoperative anemia, blood transfusions, and transfers to rehabilitation, but otherwise had complications comparable to those of the staged groups. In-hospital charges were lower in the same-day group. Congestive heart failure and pulmonary hypertension were the most significant factors associated with morbidity and mortality in the same-day group.
  
  
  CONCLUSIONS
  In a high-volume subspecialty setting in which patients undergoing same-day bilateral TKAs were generally much healthier and younger, we found that same-day bilateral TKAs appeared to be safe.
authors.affiliation: Department of Orthopaedic Surgery, Division of Adult Reconstruction and Joint Replacement, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA, PoultsidesL@HSS.EDU.
authors.forename: Lazaros
authors.initials: L
authors.lastname: Poultsides
authors.forename: Stavros
authors.initials: S
authors.lastname: Memtsoudis
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gonzalez Della Valle
authors.forename: Ivan
authors.initials: I
authors.lastname: De Martino
authors.forename: Huong T
authors.initials: HT
authors.lastname: Do
authors.forename: Michael
authors.initials: M
authors.lastname: Alexiades
authors.forename: Thomas
authors.initials: T
authors.lastname: Sculco
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome