TY - JOUR
T1 - Union of a chronically infected internally stabilized segmental defect in the rat femur after debridement and application of rhBMP-2 and systemic antibiotic
AU - Chen, Xinqian
AU - Schmidt, Andrew H.
AU - Mahjouri, Sormeh
AU - Polly, David W.
AU - Lew, William D.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - OBJECTIVES: The goal of this study was to determine whether recombinant human bone morphogenetic protein-2 (rhBMP-2) would induce new bone formation in an internally stabilized segmental defect with a chronic bacterial infection in the rat femur and whether treatment with systemic antibiotic would enhance this effect. METHODS: A 6-mm unilateral femoral segmental defect was surgically created in 120 Sprague-Dawley rats, internally stabilized with a polyacetyl plate and 6 Kirschner wires, and contaminated with 10 colony-forming units of Staphylococcus aureus. After 2 weeks, all defects were surgically debrided and implanted with 0, 20, or 200 μg of rhBMP-2 in a type 1 bovine collagen sponge. Half of the animals in each treatment group received 4 weeks of systemic antibiotic, and half did not. Animals were euthanized at 4 or 12 weeks after debridement. Bone formation within and adjacent to the defect was assessed using microcomputed tomography, torsional failure testing and undecalcified histology. RESULTS: No substantial callus formed in the infected defects without rhBMP-2. Significantly more mineralized callus was induced with the higher dose of rhBMP-2 than with the lower dose (P = 0.001), with systemic antibiotic therapy than without (P < 0.001), and at 12 weeks after debridement compared with 4 weeks (P < 0.001). CONCLUSIONS: Recombinant human bone morphogenetic protein-2 maintained its osteoinductive capability in the presence of a chronic infection, and this property was enhanced by systemic antibiotic. This study presents an intervention that may potentially accelerate fracture healing in the presence of infection and colonized hardware, thereby permitting earlier removal of the hardware, and more timely and effective treatment of infection.
AB - OBJECTIVES: The goal of this study was to determine whether recombinant human bone morphogenetic protein-2 (rhBMP-2) would induce new bone formation in an internally stabilized segmental defect with a chronic bacterial infection in the rat femur and whether treatment with systemic antibiotic would enhance this effect. METHODS: A 6-mm unilateral femoral segmental defect was surgically created in 120 Sprague-Dawley rats, internally stabilized with a polyacetyl plate and 6 Kirschner wires, and contaminated with 10 colony-forming units of Staphylococcus aureus. After 2 weeks, all defects were surgically debrided and implanted with 0, 20, or 200 μg of rhBMP-2 in a type 1 bovine collagen sponge. Half of the animals in each treatment group received 4 weeks of systemic antibiotic, and half did not. Animals were euthanized at 4 or 12 weeks after debridement. Bone formation within and adjacent to the defect was assessed using microcomputed tomography, torsional failure testing and undecalcified histology. RESULTS: No substantial callus formed in the infected defects without rhBMP-2. Significantly more mineralized callus was induced with the higher dose of rhBMP-2 than with the lower dose (P = 0.001), with systemic antibiotic therapy than without (P < 0.001), and at 12 weeks after debridement compared with 4 weeks (P < 0.001). CONCLUSIONS: Recombinant human bone morphogenetic protein-2 maintained its osteoinductive capability in the presence of a chronic infection, and this property was enhanced by systemic antibiotic. This study presents an intervention that may potentially accelerate fracture healing in the presence of infection and colonized hardware, thereby permitting earlier removal of the hardware, and more timely and effective treatment of infection.
KW - Antibiotic
KW - Bone morphogenetic protein-2
KW - Chronic infection
KW - Debridement
KW - Segmental defect
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U2 - 10.1097/BOT.0b013e31815a7e91
DO - 10.1097/BOT.0b013e31815a7e91
M3 - Article
C2 - 17986886
AN - SCOPUS:35948933000
SN - 0890-5339
VL - 21
SP - 693
EP - 700
JO - Journal of orthopaedic trauma
JF - Journal of orthopaedic trauma
IS - 10
ER -