title: Smoking Increases the Rate of Reoperation for Infection within 90 Days After Primary Total Joint Arthroplasty.
abstract: BACKGROUND
  The relationship between smoking and complications after total joint arthroplasty is unclear. Prior studies have been limited by relatively small sample sizes or investigation of select cohorts. The purpose of this study was to investigate the association between smoking and readmission and/or reoperation within 90 days of total joint arthroplasty in a large, non-select cohort of patients.
  
  
  METHODS
  Using our institutional database, we retrospectively identified patients who underwent primary total joint arthroplasty between 2000 and 2014. Patients were stratified into 1 of 3 groups: current smokers, former smokers, and nonsmokers. The association between smoking status and subsequent readmission and/or reoperation within 90 days was investigated using multivariate regression analysis.
  
  
  RESULTS
  We retrospectively identified 15,264 patients (6,749 male and 8,515 female) who underwent 17,394 total joint arthroplasties during the study period. Of these patients, 1,371 (9.0%) were current smokers, 5,195 (34.0%) were former smokers, and 8,698 (57.0%) were nonsmokers. Former smokers reported a median of 22.2 years (range, 0.2 to 60 years) of abstinence prior to the surgical procedure. Current smokers were significantly younger (p < 0.001) at a mean age (and standard deviation) of 57.7 ± 10.3 years than nonsmokers at 63.2 ± 11.8 years. Current smokers were significantly more likely than nonsmokers to undergo reoperation for infection (odds ratio [OR], 1.82 [95% confidence interval (CI), 1.03 to 3.23]; p = 0.04), and former smokers were at no increased risk (OR, 1.11 [95% CI, 0.73 to 1.69]; p = 0.61). Packs per decade were independently associated with an increased risk of 90-day nonoperative readmission regardless of smoking status (OR, 1.12 [95% CI, 1.03 to 1.20]). Lastly, neither smoking status nor packs per decade were associated with aseptic or total reoperations.
  
  
  CONCLUSIONS
  This study, after controlling for confounding factors, demonstrated not only that current smokers have a significantly increased risk of reoperation for infection within 90 days of a surgical procedure compared with nonsmokers, but also that the amount that one has smoked, regardless of current smoking status, significantly contributed to increased risk of nonoperative readmission.
  
  
  METHODS
  Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: 1Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Tischler
authors.forename: Laura
authors.initials: L
authors.lastname: Matsen Ko
authors.forename: Antonia F
authors.initials: AF
authors.lastname: Chen
authors.forename: Mitchell G
authors.initials: MG
authors.lastname: Maltenfort
authors.forename: Jacob
authors.initials: J
authors.lastname: Schroeder
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Austin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000706:statistics & numerical data*; D002648:Child; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D055815:Young Adult