title: Risk Factors for Deep Infection Following Plate Fixation of Proximal Tibial Fractures.
abstract: BACKGROUND
  The risk factors are unclear for deep surgical site infection after plate fixation of proximal tibial fractures. The objective of this study was to identify the patient and surgical procedure-related risk factors for infection using established criteria for deep surgical site infection.
  
  
  METHODS
  A total of 655 proximal tibial fractures were treated with open reduction and plate fixation at our center between 2004 and 2013. We identified 34 patients with deep surgical site infection. A control group of 136 patients was randomly selected from the non-infected cohort. Potential risk factors for deep surgical site infection were identified by reviewing surgical, medical, and radiographic records. Independent risk factors for infection were identified from multivariable logistic regression analysis using a stepwise procedure.
  
  
  RESULTS
  The prevalence of deep surgical site infection was 5.2%, the mean age of affected patients was 55 years (range, 16 to 84 years), and 35% of patients were female. Twenty-eight of 34 deep infections were diagnosed within 2 months (acute onset), and only 6 infections were diagnosed >6 months after the index surgical procedure. Nine of the 28 acute-onset infections were treated with antibiotic therapy and debridement. Seventeen patients (50%) required muscle flap coverage, and 5 patients (15%) eventually required above-the-knee amputation. In the multivariable logistic regression analysis with odds ratios (ORs) and 95% confidence intervals (95% CIs), independent predictors of infection were patient age of ≥50 years (OR, 3.6 [95% CI, 1.3 to 10.1]); obesity, defined as a body mass index of ≥30 kg/m(2) (OR, 6.5 [95% CI, 2.2 to 18.9]); alcohol abuse (OR, 6.7 [95% CI, 2.4 to 19.2]); OTA/AO-type-C fracture (OR, 2.8 [95% CI, 1.1 to 7.5]); use of a temporary spanning external fixator (OR, 3.9 [95% CI, 1.4 to 11.1]); and a 4-compartment fasciotomy (OR, 4.5 [95% CI, 1.3 to 15.7]).
  
  
  CONCLUSIONS
  There is high morbidity associated with deep surgical site infection in plated proximal tibial fractures. Patients who are ≥50 years of age, obese patients, those with a history of alcohol abuse, or those with an OTA/AO-type-C fracture are at high risk for infection. Performing a fasciotomy also increases the risk of deep infection and should be implemented with meticulous technique when deemed necessary.
  
  
  METHODS
  Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Helsinki, Helsinki, Finland Helsinki University Hospital, Helsinki, Finland markus.parkkinen@hus.fi.
authors.forename: Markus
authors.initials: M
authors.lastname: Parkkinen
authors.affiliation: Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston, Massachusetts Harvard Medical School, Boston, Massachusetts.
authors.forename: Rami
authors.initials: R
authors.lastname: Madanat
authors.affiliation: Department of Orthopaedics and Traumatology, University of Helsinki, Helsinki, Finland Helsinki University Hospital, Helsinki, Finland.
authors.forename: Jan
authors.initials: J
authors.lastname: Lindahl
authors.affiliation: Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ontario, Canada University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tatu J
authors.initials: TJ
authors.lastname: Mäkinen
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000437:Alcoholism / Q000150:complications; D015992:Body Mass Index; D001860:Bone Plates / Q000009:adverse effects*; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000379:methods; D005597:Fractures, Open / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000209:etiology*; D013978:Tibial Fractures / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult