Related Experiment Video
Updated: Apr 5, 2026
Pseudofracture: An Acute Peripheral Tissue Trauma Model
Published on: April 18, 2011
Contaminated open fracture and crush injury: a murine model
Shawn R Gilbert1, Justin Camara2, Richard Camara2
1Department of Surgery, University of Alabama at Birmingham , AL USA.
Abstract:
Modern warfare has caused a large number of severe extremity injuries, many of which become infected. In more recent conflicts, a pattern of co-infection with Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus has emerged. We attempted to recreate this pattern in an animal model to evaluate the role of vascularity in contaminated open fractures. Historically, it has been observed that infected bones frequently appear hypovascular, but vascularity in association with bone infection has not been examined in animal models. Adult rats underwent femur fracture and muscle crush injury followed by stabilization and bacterial contamination with A. baumannii complex and methicillin-resistant Staphylococcus aureus. Vascularity and perfusion were assessed by microCT angiography and SPECT scanning, respectively, at 1, 2 and 4 weeks after injury. Quantitative bacterial cultures were also obtained. Multi-bacterial infections were successfully created, with methicillin-resistant S. aureus predominating. There was overall increase in blood flow to injured limbs that was markedly greater in bacteria-inoculated limbs. Vessel volume was greater in the infected group. Quadriceps atrophy was seen in both groups, but was greater in the infected group. In this animal model, infected open fractures had greater perfusion and vascularity than non-infected limbs.
Insights
Infected open fractures in rats showed increased blood flow and vascularity compared to non-infected limbs. This study examined co-infections with Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus.
Area of Science:
- Orthopedic Surgery
- Infectious Diseases
- Vascular Biology
Background:
- Modern warfare leads to severe extremity injuries, often resulting in infections.
- A concerning pattern of co-infection with Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) has emerged in recent conflicts.
- The relationship between vascularity and bone infection in open fractures remains under-examined.
Purpose of the Study:
- To establish an animal model of co-infection with A. baumannii and MRSA in open fractures.
- To investigate the role of vascularity in the context of contaminated open fractures.
- To evaluate changes in limb vascularity and perfusion following bacterial inoculation.
Main Methods:
- Adult rats with femur fractures and muscle crush injuries were contaminated with A. baumannii complex and MRSA.
- Vascularity and perfusion were assessed using microCT angiography and SPECT scanning at 1, 2, and 4 weeks post-injury.
- Quantitative bacterial cultures and muscle atrophy assessments were performed.
Main Results:
- A multi-bacterial infection model was successfully created, with MRSA being predominant.
- Infected limbs exhibited increased perfusion and vascularity compared to non-infected limbs.
- Quadriceps atrophy was observed in both groups, but was more pronounced in the infected group.
Conclusions:
- Infected open fractures in this rat model demonstrated enhanced perfusion and vascularity.
- The findings challenge the historical assumption of hypovascularity in infected bones.
- This model provides a platform for further research into the pathophysiology of complex limb infections.
