title: Pathogen-driven decision for implant retention in the management of infected total knee prostheses.
abstract: OBJECTIVE
  In prosthetic joint infections (PJIs) of the knee, debridement with implant retention is associated with a high risk of recurrence.
  
  
  METHODS
  A single-centre cohort study was performed with extensive analysis of the literature covering 1980-2012.
  
  
  RESULTS
  In 21 patients (mean age 80.4 years, 19 immunosuppressed), in association with 1.5-three months of antibiotic treatment, an attempt was made to salvage the prosthesis by open (11 patients) or arthroscopic (ten patients) debridement. After a mean follow-up of seven years (range four-20 years), patients were in remission in seven cases (33 %). Remission was achieved in 0 % of all methicillin-resistant Staphylococcus aureus (MRSA) infections (zero/three), in 0 % (zero/three) of methicillin-resistant coagulase-negative staphylococcal infections, in 29 % (two/seven) of methicillin-sensitive S. aureus infections and in 75 % (three/four) of infections due to streptococci. The literature review focused on implant preserving approaches yielded 599 cases with an overall success rate of 47 % (284/599) and significantly more remissions in streptococcal vs staphylococcal knee PJIs (43/54 vs 144/324; p < 0.01, odds ratio 4.9, 95 % confidence interval 2.4-10.9).
  
  
  CONCLUSIONS
  In addition to established indications for explantation such as implant loosening, sinus tract or methicillin resistance, the decision for debridement and retention of knee PJIs should also depend on the pathogen. Implant preservation is futile with methicillin-resistant staphylococci, but seems to be a valid option for streptococcal PJIs.
authors.affiliation: Orthopedic Surgery Service, Geneva University Hospitals & Faculty of Medicine, University of Geneva, 4, Rue Gabrielle Perret-Gentil, 1211, Geneva 14, Switzerland.
authors.forename: Line
authors.initials: L
authors.lastname: Zürcher-Pfund
authors.forename: Ilker
authors.initials: I
authors.lastname: Uçkay
authors.forename: Laurence
authors.initials: L
authors.lastname: Legout
authors.forename: Axel
authors.initials: A
authors.lastname: Gamulin
authors.forename: Pierre
authors.initials: P
authors.lastname: Vaudaux
authors.forename: Robin
authors.initials: R
authors.lastname: Peter
mesh_terms: D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D015331:Cohort Studies; D003646:Debridement; D003937:Diagnosis, Differential; D019468:Disease Management; D005260:Female; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects* / Q000382:microbiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification; D060489:Prosthesis Retention; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D013291:Streptococcus / Q000302:isolation & purification