title: Systemic antibiotic therapy does not significantly improve outcome in a rat model of implant-associated osteomyelitis induced by Methicillin susceptible Staphylococcus aureus.
abstract: BACKGROUND
  Treatment of implant-associated osteomyelitis regularly involves the use of systemic antibiotics in addition to surgical intervention. However, it remains unclear if perioperative systemic application of bactericide substances can improve overall outcome in models of severe intramedullary infection. The present study investigated the use of systemic gentamicin in addition to a controlled local release from a highly lipophilic gentamicinpalmitate compound while the previous study showed efficacy of sole antibiotic implant-coating.
  
  
  METHODS
  Forty male Sprague-Dawley rats were divided into two groups receiving an intramedullary femoral injection of 10(2) CFU of a common methicillin susceptible Staphylococcus aureus strain (MSSA Rosenbach). Group I received an uncoated implant whereas group II received a coated implant. All animals received a single shot intraperitoneal application of gentamicinsulfate directly after wound closure while the historical control group III (n = 20) had no antibiotic treatment at all. Animals were observed for 28 and 42 days. Serum haptoglobin and relative weight gain were assessed as well as roll over cultures of explanted femur nails and histological scores of periprosthetic infection in dissected femora.
  
  
  RESULTS
  Systemic application of gentamicin combined with antibiotic-coated implant did not further reduce bacterial growth significantly compared with systemic or local antibiotic application alone. Combined local and systemic therapy reduced serum haptoglobin significantly after day 7, 28 and 42 whereas systemic application alone did not compare to controls.
  
  
  CONCLUSIONS
  Systemic perioperative and implant-associated application of antibiotics were both comparably effective to treat implant-associated infections whereas the combined antibiotic therapy further reduced systemic signs of infection time dependent.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Gießen, Marburg, Germany.|Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Fölsch
authors.affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Federmann
authors.affiliation: Department of Orthopaedics, University Hospital Goettingen, Göttingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Lakemeier
authors.affiliation: Department of Orthopaedics and Orthopaedic Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Kuehn
authors.affiliation: Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Kittinger
authors.affiliation: Institute of Medical Microbiology and Hygiene, Philipps-University Marburg, Marburg, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Kerwat
authors.affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Fuchs-Winkelmann
authors.affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany.
authors.forename: Jürgen R J
authors.initials: JR
authors.lastname: Paletta
authors.affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany. philip.roessler@ukb.uni-bonn.de.|Department of Orthopaedics and Traumatology, University Hospital Bonn, Sigmund-Freud-Str. 25, 53127, Bonn, Germany. philip.roessler@ukb.uni-bonn.de.
authors.forename: Philip P
authors.initials: PP
authors.lastname: Roessler
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005839:Gentamicins / Q000008:administration & dosage* / Q000627:therapeutic use; D007274:Injections, Intraperitoneal; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D010019:Osteomyelitis / Q000209:etiology / Q000517:prevention & control*; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013203:Staphylococcal Infections / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins
keywords: Gentamicinpalmitate; Gentamicinsulfate; Osteomyelitis; Rat model; Staphylococcus aureus; Systemic antibiotics