1/15/2024 0 Comments Comminuted open fracture pictures![]() 13ĭespite clinical observations that infected bones often lose their blood supply, no studies have attempted to quantify vascularity and perfusion in the setting of contaminated open fractures. 1– 4, 13, 14 This model was originally developed with a mixed Gram-positive/Gram-negative contamination and was modified in this study to include ABC and MRSA to more accurately reflect the clinical condition outlined above. In this study, we used a rat model that mimics the combat-related extremity injury described above, attempting to reproduce the five basic components of infected open fractures: a comminuted, high-energy fracture pattern soft-tissue necrosis bone loss periosteal stripping and bacterial contamination. 10– 12 Nevertheless, it has been speculated that early wound contamination with ABC facilitates persistence or development of infection with S. 8, 9 Additionally, ABC is known to form biofilms, which could facilitate bone and implant infection, although this feature was not observed in an animal model of implant-associated ABC osteomyelitis. 5– 7 ABC is characterized by a high rate of mutation leading to development of multi-drug resistance and persistence on surfaces despite standard antiseptic treatment. These organisms have also become concerning pathogens in nosocomial infection outbreaks. 3 ABC is a common group of bacteria found in soil and was a frequent wound contaminant during the Vietnam War. 2 In a report of combat-associated open tibial fractures, bone healing was delayed in one-third of wounds that were ultimately infected with Staphylococcus species. 3 These pathogens seem to be of comparatively low virulence and are later replaced by Gram-positive organisms such as Staphylococcus aureus, including methicillin-resistant strains ( MRSA). 4 Early in the course, Gram-negative pathogens such as Acinetobacter baumannii complex ( ABC) and Pseudomonas aueruginosa are present. Initial wound cultures usually show predominantly skin bacteria. ![]() 2, 3 New patterns of infection of extremity wounds have emerged in recent military conflicts. 1 A difficult and frequent complication of these injuries is deep infection, which may occur in as many as 15% of wounds overall and as many as half of severe open tibial fracture wounds. A large proportion of these were severe extremity injuries (often as a result of improvised explosive devices) involving extensive soft tissue damage with open fractures. The United States sustained more than 52 000 wounded-in-action casualties in operations Iraqi Freedom, New Dawn and Enduring Freedom ( ). In this animal model, infected open fractures had greater perfusion and vascularity than non-infected limbs. Quadriceps atrophy was seen in both groups, but was greater in the infected group. Vessel volume was greater in the infected group. There was overall increase in blood flow to injured limbs that was markedly greater in bacteria-inoculated limbs. Multi-bacterial infections were successfully created, with methicillin-resistant S. Quantitative bacterial cultures were also obtained. Vascularity and perfusion were assessed by microCT angiography and SPECT scanning, respectively, at 1, 2 and 4 weeks after injury. baumannii complex and methicillin-resistant Staphylococcus aureus. Adult rats underwent femur fracture and muscle crush injury followed by stabilization and bacterial contamination with A. 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. ![]() We attempted to recreate this pattern in an animal model to evaluate the role of vascularity in contaminated open fractures. In more recent conflicts, a pattern of co-infection with Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus has emerged. Modern warfare has caused a large number of severe extremity injuries, many of which become infected. ![]()
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