title: Effect of body mass index on patients with multiligamentous knee injuries.
abstract: OBJECTIVE
  Our goal was to evaluate the impact of body mass index (BMI) on complications and associated injuries in patients undergoing surgical treatment for multiligamentous knee injuries (MLKIs).
  
  
  METHODS
  Over a period of 10 years, 126 MLKIs (123 patients) were included in the study. The inclusion criteria were (1) injury to 2 or more knee ligaments, (2) multiligament repair and/or reconstruction performed by 1 of 3 sports medicine orthopaedic surgeons at our institution, and (3) minimum of 1 year of follow-up. A chart review was performed to collect demographic data, mechanism of injury, ligaments involved, complications, and associated neurovascular injuries. Lastly, patients were divided by BMI into non-obese (<30 kg/m(2)) and obese (≥30 kg/m(2)) groups.
  
  
  RESULTS
  Of the 126 MLKIs, 87 occurred in non-obese patients and 39 occurred in obese patients. Surgical complication rates for non-obese and obese patients were 8.05% and 15.4%, respectively (P = .21). Revisions were needed in 8.05% and 5.1% of patients in these groups, respectively (P = .72). Three wound complications were found in the obese group only. Vascular injuries were found in 2.3% and 7.7% of patients in the non-obese and obese groups, respectively (P = .17). The rates of nerve injuries were 11.49% and 20.51%, respectively (P = .18). Patients in the obese group were most likely to have an MLKI from low-energy mechanisms, disregarding sports-related injuries (51.28%, P = .02). Using a logistic model and BMI as a continuous variable, we found that a 1-unit increase in BMI increased the odds ratio of complications by 9.2%, with statistical significance (P = .0174). In addition, post hoc power analysis using previous literature showed that this study could produce satisfactory power.
  
  
  CONCLUSIONS
  Our results indicate that (1) obese individuals are significantly more likely to have an MLKI caused by low-energy mechanisms and (2) complication rates increase by 9.2% for every 1-unit increase in BMI.
  
  
  METHODS
  Level III, retrospective comparative study.
authors: University of Iowa Carver College of Medicine, Iowa City, Iowa, U.S.A.. Electronic address: taylor-ridley@uiowa.edu.
authors: T J
authors: TJ
authors: Ridley
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Shane
authors: S
authors: Cook
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Matthew
authors: M
authors: Bollier
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Mark
authors: M
authors: McCarthy
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Yubo
authors: Y
authors: Gao
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Brian
authors: B
authors: Wolf
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, U.S.A.
authors: Annunziato
authors: A
authors: Amendola
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000150:complications* / Q000601:surgery; D008023:Ligaments, Articular / Q000293:injuries* / Q000601:surgery; D008297:Male; D009104:Multiple Trauma / Q000150:complications* / Q000601:surgery; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D057772:Vascular System Injuries / Q000453:epidemiology