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· DOS Abstracts
In-Vivo and In-Vitro Evaluation of Vancomycin and
Gentamicin Elution from Bone Graft Substitutes
Thomas Colding-Rasmussen, Peter Horstmann, Hanna Dahlgren, Eva Lidén,
Werner Hettwer, Michael Mørk Petersen
Department of Orthopedics, Musculoskeletal Tumor Section, Rigshospitalet, University
of Copenhagen, Denmark ; Department of Orthopedics, Musculoskeletal Tumor Section,
Rigshospitalet, University of Copenhagen, Denmark ; , BONESUPPORT AB, Lund, Sweden;
, BONESUPPORT AB, Lund, Sweden; Department of Orthopedics, Musculoskeletal
Tumor Section, Rigshospitalet, University of Copenhagen, Denmark ; Department of
Orthopedics, Musculoskeletal Tumor Section, Rigshospitalet, University of Copenhagen,
Denmark
Background:
Antibiotic containing materials are often used for dead space management
after surgical treatment of bone infections.
Purpose / Aimof Study:
Tomeasure early in-vivo plasma concentrations of Vancomycin
and Gentamicin eluted from locally implanted antibiotic-eluting bone graft substitutes
(BGS), and to evaluate possible in-vitro elution interactions of combined use.
Materials and Methods:
In-vivo plasma concentrations were measured in 5 patients
(M/F: 3/2, mean age 67 (52-81) years), who underwent local implantation (range: 10-
20 mL) with either a Vancomycin- (n=1), a Gentamicin-eluting BGS (n=3) or a combi-
nation of both (n=1). Plasma was collected 1 and 3 hours after implantation and once
daily during the first three postoperative days. In-vitro elution profiles of Vancomycin-
and Gentamicin-eluting BGS (5 mL each) were compared in 4 different scenarios: Each
product individually, both products side-by-side, and mixed together. The ratio between
product and medium was kept the same in all tests. Samples (20% of the medium to
mimic conditions in a contained bone defect) were collected and replaced on day 1-8,
21, and 28 for analysis.
Findings / Results:
Mean blood plasma concentration of Vancomycin was 0.3 mg/L
(Range: 0.0- 1.6mg/L) and 0.5 mg/L (Range: 0.0- 2.1mg/L) for Gentamicin. In-vitro
release curves of Vancomycin and Gentamicin showed a similar appearance for the 4 dif-
ferent scenarios. Both the in-vivo and in-vitro curves displayed an initial peak, a gradual
drop, and sustained lower concentrations during the study period.
Conclusions:
Local in-vivo implantation of Vancomycin- and Gentamicin-eluting bone
graft substitutes, results in safe low plasma concentrations in the first three days after
surgery when used individually or in combination. Further, when tested in-vitro, com-
bined use did not seem to influence their eluting abilities.
Conflicts of Interest
Peter Horstmann: Fundet by BONESUPPORT AB
Hanna Dahlgren: Employee at BONESUPPORT AB
Eva Lidén; Employee at BONESUPPORT AB
Werner Hettwer; BONESUPPORT AB
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