title: Effect of surgeon fatigue on hip and knee arthroplasty.
abstract: BACKGROUND
  There is growing support in the literature that patient outcomes are adversely affected by physician fatigue in operator-dependent cognitive and technical tasks. Recent increases in total joint arthroplasty caseloads have resulted in longer operative days and increased surgeon fatigue. We sought to determine if time of day predicts perioperative complications and outcomes in total joint arthroplasty.
  
  
  METHODS
  The records of all total hip and knee arthroplasties (THA; TKA) performed for primary osteoarthritis in one calendar year at one large university hospital were retrospectively reviewed. Demographic data, surgery start time and duration, intraoperative complications, radiographic component alignment and functional outcome scores (SF-12 and Western Ontario and McMaster Universities Osteoarthritis Index) were collected and analyzed using linear and nonparametric rank correlation statistics. Data were corrected for sex, body mass index, surgeon and postcall operating days.
  
  
  RESULTS
  In the THA cohort (n=341), a later surgery start time was significantly related to duration of surgery (p= 0.004, mean difference -7.1 min). There was a trend toward significance between a later surgery start time and intraoperative femur fracture (p= 0.05). Postoperative complications, component alignment and functional outcome scores were not significantly affected by surgery start time. There were no significant findings for any of the intraoperative or postoperative outcomes in the TKA cohort (n=292).
  
  
  CONCLUSIONS
  Duration of surgery and incidence of intraoperative complications for THA may increase with later surgery start time; however, the relatively small statistical differences observed imply that they likely are not clinically significant.
authors.affiliation: Division of Orthopaedic Surgery, St. Michael's Hospital, University of  Toronto, Toronto, Ont.
authors.forename: Christopher
authors.initials: C
authors.lastname: Peskun
authors.forename: David
authors.initials: D
authors.lastname: Walmsley
authors.forename: James
authors.initials: J
authors.lastname: Waddell
authors.forename: Emil
authors.initials: E
authors.lastname: Schemitsch
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data*; D002940:Circadian Rhythm; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D005222:Mental Fatigue / Q000150:complications / Q000453:epidemiology*; D008875:Middle Aged; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000453:epidemiology*; D009864:Ontario; D009985:Orthopedics / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011786:Quality Control; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome; D016526:Workload / Q000706:statistics & numerical data*; D055815:Young Adult