title: Drain tip cultures do not predict infections in primary total knee arthroplasty.
abstract: The possibility to predict surgical site infections development could be of high prognostic value. We aimed to investigate whether cultures obtained from the tip of the closed passive wound drain may provide early signs of progression towards periprosthetic joint infections.
  
  
  
  We performed an observational study on consecutive primary total knee arthroplasties performed in our department over 4 years by two high volume surgeons (it means they do a lot of arthroplasties/year; it is orthopedics specific). A total of 284 knees in 257 patients were included. Follow up was available for an average of 18.7 months. There were no simultaneous procedures.
  
  
  
  Nineteen (6.69%) drain tips yielded positive cultures, for a mean duration, from surgery to sample collection, of 1.63 (0.5) days. None of the positive drain tip cultures developed clinical signs of infection and all knees were healed at discharge after a mean of 13.78 days (SD= 3.34; range= 8-18). None of the 7 (2.46%) cases who developed deep infections had positive drain tip cultures. A true positive value of 0 led to a positive predictive value of 0, a negative predictive value of 97.34%, sensitivity of 0% and specificity of 93.14.
  
  
  
  The diagnostic use of passive drain tip cultures to detect early infections after total knee replacement is therefore absolutely useless.
authors.affiliation: Deparments of Second Clinic of Infectious Diseases, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: V
authors.initials: V
authors.lastname: Lazureanu
authors.affiliation: Department of First Clinic of Surgery, University of Medicine and Pharmacy 'Victor babes' Timisoara, Romania.
authors.forename: D
authors.initials: D
authors.lastname: Radu
authors.affiliation: Deparments of Orthopedics and Trauma, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: D
authors.initials: D
authors.lastname: Vermesan
authors.affiliation: Deparments of Orthopedics and Trauma, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: R
authors.initials: R
authors.lastname: Prejbeanu
authors.affiliation: Deparments of Orthopedics and Trauma, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: S
authors.initials: S
authors.lastname: Florescu
authors.affiliation: Deparments of Orthopedics and Trauma, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: I
authors.initials: I
authors.lastname: Trocan
authors.affiliation: West University 'Vasile Goldis', Arad, Romania.
authors.forename: S
authors.initials: S
authors.lastname: Damian
authors.affiliation: Departments of Interdisciplinary Medicine, School of Medicine, University of Bari, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Inchingolo
authors.affiliation: Departments of Biomedical Sciences and Human Oncology School of Medicine, University of Bari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Abbinante
authors.affiliation: Departments of Interdisciplinary Medicine, School of Medicine, University of Bari, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Dipalma
authors.affiliation: Departments of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Caprio
authors.affiliation: Departments of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cagiano
authors.affiliation: Departments of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Potenza
authors.affiliation: Deparments of Orthopedics and Trauma, University of Medicine and Pharmacy 'Victor Babes' Timisoara, Romania.
authors.forename: H
authors.initials: H
authors.lastname: Haragus
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D004322:Drainage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016459:Prosthesis-Related Infections / Q000453:epidemiology* / Q000382:microbiology; D012680:Sensitivity and Specificity
keywords: Knee; Passive drain tip culture; Periprosthetic joint infection; Primary arthroplasty; Total joint replacement