TY - JOUR
T1 - A novel knee prosthesis model of implant-related osteo- myelitis in rats
AU - Søe, Niels H.
AU - Jensen, Nina Vendel
AU - Nürnberg, Birgit Meinecke
AU - Jensen, Asger Lundorff
AU - Koch, Janne
AU - Poulsen, Steen Seier
AU - Pier, Gerald
AU - Johansen, Helle Krogh
PY - 2013/2
Y1 - 2013/2
N2 - Background and purpose There have been numerous reports of animal models of osteomyelitis. Very few of these have been prosthesis models that imitate human conditions. We have developed a new rat model of implant-related osteomyelitis that mimics human osteomyelitis, to investigate the pathology of infection after orthop edic implant surgery. Methods 2 wild-type strains of Staphylococcus aureus, MN8 and UAMS-1, and their corresponding mutants that are unable to produce poly-N-acetyl glucosamine (PNAG) (ica::tet) were injected into the medullary canals of the femur and tibia at 3 different doses: 10, 10, and > 10 CFU/rat. We measured clinical signs, inflammatory markers, radiographic signs, histopathology, and bacteriology in the infected animals. Results An inoculum of at least 10 cfu of either wild-type bacterial strain resulted in histological, bacteriological, and radiographic signs of osteomyelitis with loosening of the prosthesis. An inoculum of 10 CFU gave signs of osteomyelitis but the prosthesis remained in situ. Bacterial inocula of 10 cfu gave no signs of osteolysis. Interpretation We have established a new knee prosthesis model that is suitable for reliable induction of experimental implant-associated osteomyelitis with the prosthesis in situ, using a small inoculum of S. aureus. At a dose of 10 CFU/rat, bacteria unable to produce PNAG (ica::tet) had only minor defects in their virulence.
AB - Background and purpose There have been numerous reports of animal models of osteomyelitis. Very few of these have been prosthesis models that imitate human conditions. We have developed a new rat model of implant-related osteomyelitis that mimics human osteomyelitis, to investigate the pathology of infection after orthop edic implant surgery. Methods 2 wild-type strains of Staphylococcus aureus, MN8 and UAMS-1, and their corresponding mutants that are unable to produce poly-N-acetyl glucosamine (PNAG) (ica::tet) were injected into the medullary canals of the femur and tibia at 3 different doses: 10, 10, and > 10 CFU/rat. We measured clinical signs, inflammatory markers, radiographic signs, histopathology, and bacteriology in the infected animals. Results An inoculum of at least 10 cfu of either wild-type bacterial strain resulted in histological, bacteriological, and radiographic signs of osteomyelitis with loosening of the prosthesis. An inoculum of 10 CFU gave signs of osteomyelitis but the prosthesis remained in situ. Bacterial inocula of 10 cfu gave no signs of osteolysis. Interpretation We have established a new knee prosthesis model that is suitable for reliable induction of experimental implant-associated osteomyelitis with the prosthesis in situ, using a small inoculum of S. aureus. At a dose of 10 CFU/rat, bacteria unable to produce PNAG (ica::tet) had only minor defects in their virulence.
U2 - 10.3109/17453674.2013.773121
DO - 10.3109/17453674.2013.773121
M3 - Journal article
C2 - 23409845
SN - 1745-3674
VL - 84
SP - 92
EP - 97
JO - Acta Orthopaedica
JF - Acta Orthopaedica
IS - 1
ER -