title: The use of a biodegradable, load-bearing scaffold as a carrier for antibiotics in an infected open fracture model.
abstract: OBJECTIVE
  Open fractures with bone loss are common, disabling injuries. Biodegradable, load-bearing scaffolds able to carry high concentrations of local antibiotics are an emerging technology to address these injuries. This study investigates the use of such scaffolds with gentamicin (along with bone morphogenetic protein) in an infected rat open fracture model to decrease osteomyelitis and promote fracture healing.
  
  
  METHODS
  A contaminated open fracture was created in 32 Brown Norway rats. A comminuted femoral fracture was created, followed by crushing, and the 5-mm bone defect was inoculated with Staphylococcus aureus (10 colony-forming units/mL) and Escherichia coli (10 colony-forming units/mL). The scaffold was stabilized in the defect with an intramedullary Kirschner wire. Gentamicin was loaded onto the scaffolds at two doses, either 10 mg (n = 12) or 20 mg (n = 10). Controls (n = 10) received no antibiotics. All three groups had 10 microg bone morphogenetic protein loaded on the scaffold. Serial radiographs were obtained. Microbiologic analysis, microcomputed tomography, and histology were performed.
  
  
  RESULTS
  There was a statistically significant difference in the radiographic evidence of osteomyelitis (P = 0.004) and callus formation (P = 0.021) between the treated and control groups. Bone culture analysis results were not significant for S. aureus (P = 0.29) or E. coli (P = 0.25). There was no difference in the mean scaffold volume or density of the three treatment groups.
  
  
  CONCLUSIONS
  Our results suggest that gentamicin applied to a biodegradable scaffold is effective at decreasing radiographically defined osteomyelitis in an infected open fracture.
authors.affiliation: Division of Orthopaedics, University of Alabama at Birmingham, Birmingham, AL 35233-3409, USA. Rena.Stewart@ortho.uab.edu
authors.forename: Rena L
authors.initials: RL
authors.lastname: Stewart
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Cox
authors.forename: David
authors.initials: D
authors.lastname: Volgas
authors.forename: James
authors.initials: J
authors.lastname: Stannard
authors.forename: Lynn
authors.initials: L
authors.lastname: Duffy
authors.forename: Ken B
authors.initials: KB
authors.lastname: Waites
authors.forename: Tien-Min
authors.initials: TM
authors.lastname: Chu
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004337:Drug Carriers; D005264:Femoral Fractures / Q000188:drug therapy / Q000382:microbiology; D017102:Fracture Healing / Q000187:drug effects / Q000502:physiology; D005597:Fractures, Open / Q000188:drug therapy* / Q000382:microbiology; D005839:Gentamicins / Q000008:administration & dosage*; D010019:Osteomyelitis / Q000188:drug therapy* / Q000382:microbiology; D051381:Rats; D011914:Rats, Inbred BN; D054457:Tissue Scaffolds; D016896:Treatment Outcome; D016474:Weight-Bearing
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D005839:Gentamicins