title: Evaluation of antibiotic-impregnated microspheres for the prevention of implant-associated orthopaedic infections.
abstract: BACKGROUND
  Prevention of infection associated with uncemented orthopaedic implants could lead to improved implant stability and better patient outcomes. We hypothesized that coating porous metal implants with antibiotic-containing microspheres would prevent infections in grossly contaminated wounds.
  
  
  METHODS
  Bioresorbable polymer microspheres containing tobramycin were manufactured and pressed into porous metal cylinders that were then implanted into radial defects in rabbits. Control implants that did not contain antibiotic microspheres were also implanted into the contralateral limbs. Each implant was then contaminated with Staphylococcus aureus prior to closure of the wound. The animal was euthanized after clinical signs of infection appeared, or at two weeks after surgery. Periprosthetic tissue was cultured for the presence of S. aureus, and integration of the implant with the surrounding bone was measured.
  
  
  RESULTS
  The antibiotic microspheres successfully prevented infection in 100% of the eleven limbs with treated implants, which represented a significant improvement (p = 0.004) compared with the infection rate of 64% (seven of eleven) for the limbs with control implants. Implant integration averaged 38.87% ± 12.69% in the fifteen uninfected limbs, which was significantly better (p = 0.012) than the average of 19.46% ± 14.49% in the seven infected limbs.
  
  
  CONCLUSIONS
  The antibiotic delivery system successfully prevented infection in 100% of the cases studied, resulting in an increase in implant integration.
  
  
  CONCLUSIONS
  Antibiotic delivery utilizing the system described here may be effective in preventing implant-associated infections after orthopaedic surgery and increasing the longevity of orthopaedic implants.
authors.affiliation: Departments of Orthopaedic Surgery (C.G.A., T.A.C., and J.M.), Microbiology and Molecular Genetics (H.B.K.), and Pathology (A.W.), The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030. E-mail address for C.G. Amb.
authors.forename: Catherine G
authors.initials: CG
authors.lastname: Ambrose
authors.affiliation: Departments of Orthopaedic Surgery (C.G.A., T.A.C., and J.M.), Microbiology and Molecular Genetics (H.B.K.), and Pathology (A.W.), The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030. E-mail address for C.G. Amb.
authors.forename: Terry A
authors.initials: TA
authors.lastname: Clyburn
authors.affiliation: Departments of Orthopaedic Surgery (C.G.A., T.A.C., and J.M.), Microbiology and Molecular Genetics (H.B.K.), and Pathology (A.W.), The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030. E-mail address for C.G. Amb.
authors.forename: Joerg
authors.initials: J
authors.lastname: Mika
authors.affiliation: Shriners Orthopaedic Hospital, 6977 Main Street, Houston, TX 77030-3701.
authors.forename: Gloria R
authors.initials: GR
authors.lastname: Gogola
authors.affiliation: Departments of Orthopaedic Surgery (C.G.A., T.A.C., and J.M.), Microbiology and Molecular Genetics (H.B.K.), and Pathology (A.W.), The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030. E-mail address for C.G. Amb.
authors.forename: Heidi B
authors.initials: HB
authors.lastname: Kaplan
authors.affiliation: Departments of Orthopaedic Surgery (C.G.A., T.A.C., and J.M.), Microbiology and Molecular Genetics (H.B.K.), and Pathology (A.W.), The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030. E-mail address for C.G. Amb.
authors.forename: Audrey
authors.initials: A
authors.lastname: Wanger
authors.affiliation: Department of Bioengineering, Rice University, P.O. Box 1892, Houston, TX 77251.
authors.forename: Antonios G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D008297:Male; D008863:Microspheres; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D016459:Prosthesis-Related Infections / Q000188:drug therapy / Q000517:prevention & control*; D011817:Rabbits; D011897:Random Allocation; D012016:Reference Values; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000517:prevention & control*; D014031:Tobramycin / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D014031:Tobramycin