title: Obesity has no effect on outcomes following unicompartmental knee arthroplasty.
abstract: OBJECTIVE
  Although obesity has historically been described as a contraindication to UKA, improved outcomes with modern UKA implant designs have challenged this perception. The purpose of this study was to assess the influence of obesity on the outcomes of UKA with a robotic-assisted system at a minimum follow-up of 24 months with the hypothesis that obesity has no effect on robotic-assisted UKA outcomes.
  
  
  METHODS
  There were 746 medial robotic-assisted UKAs (672 patients) with a mean age of 64 years (SD 11) and a mean follow-up time of 34.6 months (SD 7.8). Mean overall body mass index (BMI) was 32.1 kg/m2(SD 6.5), and patients were stratified into seven weight categories according to the World Health Organization classification.
  
  
  RESULTS
  Patient BMI did not influence the rate of revision surgery to TKA (5.8 %) or conversion from InLay to OnLay design (1.7 %, n.s.). Mean postoperative Oxford knee score was 37 (SD 11) without correlation with BMI (n.s.). The type of prosthesis (InLay/OnLay) regardless of BMI had no influence on revision rate (n.s.). BMI did not influence 90-day readmissions (4.4 %, n.s.), but showed significant correlation with higher opioid medication requirements and a higher number of physical therapy session needed to reach discharge goals (p = 0.031).
  
  
  CONCLUSIONS
  These findings suggest that BMI does not influence clinical outcomes and readmission rates of robotic-assisted UKA at mid-term. The classic contraindication of BMI >30 kg/m2may not be justified with the use of modern UKA designs or techniques.
  
  
  METHODS
  IV.
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA. jplate@wakehealth.edu.
authors: Johannes F
authors: JF
authors: Plate
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.|Department of Orthopaedic Surgery and Rehabilitation Medicine, University of Heidelberg, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany.
authors: Marco A
authors: MA
authors: Augart
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.
authors: Thorsten M
authors: TM
authors: Seyler
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.
authors: Daniel N
authors: DN
authors: Bracey
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.
authors: Aneitra
authors: A
authors: Hoggard
authors: Department of Orthopaedic Surgery and Rehabilitation Medicine, University of Heidelberg, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany.
authors: Michael
authors: M
authors: Akbar
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.|Southeastern Orthopedics, Southeastern Regional Medical Center, Lumberton, NC, 28358, USA.
authors: Riyaz H
authors: RH
authors: Jinnah
authors: Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.
authors: Gary G
authors: GG
authors: Poehling
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D020370:Osteoarthritis, Knee / Q000453:epidemiology / Q000601:surgery*; D011184:Postoperative Period; D012086:Reoperation; D065287:Robotic Surgical Procedures / Q000379:methods*; D016896:Treatment Outcome
keywords: Knee replacement; Medial; Navigation; Robotic assisted; UKA