A novel rat model of tibial fracture for trauma researches: a combination of different types of fractures and soft tissue injuries

Abstract

BackgroundThe outcomes for open tibial fractures with severe soft tissue injury are still a great challenge for all the trauma surgeons in the treatment. However, most of the existing open tibial fracture models can only provide minimal soft tissue injury which cannot meet the requirement of severe trauma research. Our goal is to investigate a novel tibial fracture model providing different fractures combined with soft tissue injury for better application in trauma research.MethodsA total of 144 Sprague-Dawley rats were randomly divided into 4 groups. With group 1 as control, the other groups sustained different right tibial fractures by the apparatus with buffer disc settings either 3 mm, 10 mm, or 15 mm. X-ray and computed tomography angiography (CTA) were performed at 6 h to evaluate the fracture patterns and vascular injuries. Peripheral blood and tibialis anterior muscle were harvested at 6 h, 1 day, 3 days, 7 days, 14 days, and 28 days for ELISA and histological analysis.ResultsX-ray and μCT results indicated that different fractures combined with soft tissue injuries could be successfully provided in this model. According to OTA and Gustilo classification, the fractures and soft tissue injuries were evaluated and defined: 36 type I in group 2, 34 type II in group 3, and 36 type III in group 4. The CTA confirmed no arterial injuries in groups 1 and 2, 2 arterial injuries in group 3, and 35 in group 4. ELISA indicated that the levels of pro-inflammatory cytokines TNF-α and IL-1β were significantly higher in group 4 than in other groups, and the levels of anti-inflammatory cytokines TGF-β and IL-10 were significantly higher in surgery groups than in group 1 in later stage or throughout the entire process. HE, Masson, and caspase-3 stains confirmed the most severe inflammatory cell infiltration and apoptosis in group 4 which lasted longer than that in groups 2 and 3.ConclusionsThe novel apparatus was valuable in performing different fractures combined with soft tissue injuries in a rat tibial fracture model with high reproducibility and providing a new selection for trauma research in the future.

Generation of Open Metatarsal Fracture in Rats: A Model for Secondary Fracture Healing

“…It was also reported that soft tissue trauma could delay periosteal response to healing [46,47]. The findings of this study agreed with that of Shi et al [20] where soft tissue injury persisted for seven days postoperative. Although the severity of the soft tissue damage they recorded was greater when compared to this study, the likely reason why they have severe soft tissue injury is that the fracture model they generated was the closed type.…”

“…For example, 15%, 9% and 12% of the rats were excluded by Jackson et al [11]; Manigrasso and O'Connor, [41]; Auregan et al [15] respectively. In a recent study conducted by Shi et al [20], the complications of closed tibial fracture was categorized into type I to III, with type III having the severe localized injuries ranging from muscles avulsion, vascular rupture, ischemia of distal extremities and bonny comminution. These limitations make the techniques of these popular fracture models to be a little bit difficult to be reproducible without modifications.…”

“…Experimental fracture models equip investigators to test different research interventions on the normal processes of bone healing [18,19]. Most of the studies utilize rodents for fracture models, because it has been reported that fracture healing in rodents is extremely rapid and effective when compared to typical clinical scenarios [20]. Therefore, researchers must be cautious in translating outcomes related to time of fracture union or stiffness of the union in relation to clinical benefit [18].…”

Review of immunological plasma markers for longitudinal analysis of inflammation and infection in rat models

“…Injury induces an immunological response from acute tissue damage incurred during surgical procedures such as laparotomy, 31 castration, 23 or implantation of a biomaterial. Additionally, inflammation can be induced via bone fracture 40 or creation of segmental bone defects 2 …”

“…IL‐1β and IL‐10 have been explored in response to tibial fractures 40 . Fractures were created in Sprague Dawley rats using an adjustable drop tower‐blade apparatus using a 3‐, 10‐, or 15‐mm buffer disc, which controlled the depth the blade penetrated the limb 40 . For all fracture groups, a 500 g blade was dropped from 50 cm.…”