title: Does BMI influence clinical outcomes after total knee arthroplasty?
abstract: BACKGROUND
  Obesity is a common problem in the western European countries. Since the association between obesity and the emergence of gonarthrosis is approved, it is more important to gain reliable information about this patient group. The aim of the present retrospective study is to evaluate clinical outcomes of German obese patients after total knee arthroplasty (TKA).
  
  
  METHODS
  Between 2001 and 2009 a total of 199 patients with 230 TKA were included in the present study. The collective was divided into four groups in relation to their Body-Mass-Index (BMI); group 1: BMI < 25 kg/m2, n = 24; group 2: BMI 25-30 kg/m2, n = 80, group 3: BMI 30-40 kg/m2, n = 109; group 4: BMI> 40 kg/m2, n = 17. Clinical outcome measurement was scored postoperatively using the knee society score (KSS), hospital for special surgery score (HSS) and the visual analogue scale (VAS). Furthermore complications and subjective patient satisfaction were noted.
  
  
  RESULTS
  We did not detect any significant differences in the clinical scores between the BMI-subgroups. However we measured statistically significant worse results in case of infection and instability in all BMI subgroups (p> 0.01).
  
  
  CONCLUSIONS
  While infection and instability may have a negative influence for the clinical outcome, we did not detect any significant correlation between obesity and exiting complications. Obesity has no significant correlation to influence the outcome after TKA implantation negatively.
authors.affiliation: Department of Orthopaedic Surgery, Annastift Hannover (Medical School Hannover, MHH), Germany.
authors.forename: Kiriakos
authors.initials: K
authors.lastname: Daniilidis
authors.affiliation: Department of Orthopaedic Surgery, Annastift Hannover (Medical School Hannover, MHH), Germany.
authors.forename: Daiwei
authors.initials: D
authors.lastname: Yao
authors.affiliation: Department of General Orthopaedics, Tumororthopaedics University Hospital Muenster, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Gosheger
authors.affiliation: Department of General Orthopaedics, Tumororthopaedics University Hospital Muenster, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Berssen
authors.affiliation: Department of General Orthopaedics, Tumororthopaedics University Hospital Muenster, Germany.
authors.forename: Tymoteusz
authors.initials: T
authors.lastname: Budny
authors.affiliation: Department of General Orthopaedics, Tumororthopaedics University Hospital Muenster, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Dieckmann
authors.affiliation: Department of General Orthopaedics, Paracelsus Hospital Osnabrück, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Höll
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D020370:Osteoarthritis, Knee / Q000453:epidemiology* / Q000601:surgery*; D017060:Patient Satisfaction; D011183:Postoperative Complications / Q000453:epidemiology; D016459:Prosthesis-Related Infections; D012189:Retrospective Studies
keywords: Obesity; infection; outcome; total knee arthroplasty