All authors confirm that there are no conflicts of interest associated with this publication and there has been no financial support for this work that could have influenced its outcome. Financial support was provided by non-profit organizations exclusively (Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital).
We declare that this manuscript is original, has not been published before and is not currently being considered for publication elsewhere. It has been read by all authors and each of the authors is convinced that the manuscript represents honest work.
LH participated in the study design, animal surgeries, analysis of the findings, and drafting of the final manuscript. TG participated in the study design, analysis of the findings and helped draft the final manuscript. SR and AI participated in the animal surgeries and analysis of the findings. KK participated in the animal surgeries and helped draft the final manuscript. CAF and AM participated in the study design and helped draft the final manuscript. GS participated in the study design, analysis of the findings and helped draft the final manuscript. All authors read and approved the final manuscript.
The treatment of infection-related delayed bone unions is still very challenging for the orthopedic surgeon. The prevalence of such infection-related types of osteitis is high in complex fractures, particularly in open fractures with extensive soft-tissue damage. The aim of this study was to develop a new animal model for delayed union due to osteitis.
After randomization to infected or non-infected groups 20 Sprague–Dawley rats underwent a transverse fracture of the midshaft tibia. After intramedullary inoculation with staphylococcus aureus (103 CFU) fracture stabilization was done by intramedullary titanium K-wires. After 5 weeks all rats were euthanized and underwent biomechanical testing to evaluate bone consolidation or delayed union, respectively. Micro-CT scans were additionally used to quantitatively evaluate the callus formation by the score of Lane and Sandhu. Blood samples were taken to analyze infectious disease markers (day 1, 14 and 35).
Biomechanical testing showed a significant higher maximum torque in the non-infected group 5 weeks postoperatively compared with the infected group (p < 0.001). According to the Lane and Sandhu score a significantly higher callus formation was found in the non-infected group (p < 0.001). Similarly, the leucocyte count in the infected group was significantly higher than in the non-infected group (p < 0.05).
Here we have established a new animal model for delayed osseous union secondary to osteitis. The animal model appears to be appropriate for future experimental studies to test new therapeutic strategies in these difficult to treat bone healing complications.
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- A new animal model for delayed osseous union secondary to osteitis
Christian Alexander Fischer
- BioMed Central
Neu im Fachgebiet Orthopädie und Unfallchirurgie
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