title: Superobesity (body mass index >50 kg/m2) and complications after total shoulder arthroplasty: an incremental effect of increasing body mass index.
abstract: BACKGROUND
  The prevalence of obesity in the United States continues to increase. Attention has recently turned to an emerging population of extremely overweight patients, termed superobese and defined as those with body mass index (BMI) ≥50 kg/m(2). The goal of this study was to use a national database to evaluate postoperative complication rates after total shoulder arthroplasty (TSA) in superobese patients and to compare patients of different BMI classes.
  
  
  METHODS
  Patients who underwent TSA or reverse TSA were identified in the PearlDiver database by International Classification of Diseases, Ninth Revision (ICD-9) codes. These patients were then divided into nonobese, obese, morbidly obese, and superobese cohorts by ICD-9 codes. Postoperative complications were assessed and compared between cohorts.
  
  
  RESULTS
  From 2005 to 2012, 144,239 unique patients who underwent TSA or reverse TSA were identified, including 105,661 nonobese patients, 23,864 obese patients, 13,759 morbidly obese patients, and 955 superobese patients. Superobese patients had a significantly higher rate of infection, dislocation, component loosening, revision shoulder arthroplasty, venous thromboembolism, and medical complications after shoulder arthroplasty compared with nonobese controls.
  
  
  CONCLUSIONS
  Obesity is associated with significantly increased rates of numerous complications after TSA, including infection, dislocation, component loosening, revision surgery, venous thromboembolism, and medical complications, compared with nonobese controls. Superobesity (BMI > 50 kg/m(2)) is associated with significantly increased rates of several complications compared with even obese and morbidly obese patients, including infection, component loosening, venous thromboembolism, and medical complications.
authors.affiliation: Department of Orthopaedic Surgery, University of Virginia Health System, Charlottesville, VA, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Werner
authors.affiliation: Department of Orthopaedic Surgery, University of Virginia Health System, Charlottesville, VA, USA.
authors.forename: M Tyrrell
authors.initials: MT
authors.lastname: Burrus
authors.affiliation: Department of Orthopaedic Surgery, University of Virginia Health System, Charlottesville, VA, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Browne
authors.affiliation: Department of Orthopaedic Surgery, University of Virginia Health System, Charlottesville, VA, USA. Electronic address: sfb2e@virginia.edu.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Brockmeier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009767:Obesity, Morbid / Q000150:complications*; D011183:Postoperative Complications; D012086:Reoperation; D012189:Retrospective Studies; D012783:Shoulder Dislocation / Q000209:etiology; D012785:Shoulder Joint / Q000601:surgery*; D054556:Venous Thromboembolism / Q000209:etiology
keywords: Superobesity; complications; infection; reverse shoulder arthroplasty; revision shoulder arthroplasty; total shoulder arthroplasty