An innovative animal experimental model of rib fracture with bone displacement

Rib fractures, the most common blunt chest trauma worldwide, have been evaluated in multiple retrospective cohort studies. Histology laboratories using innovative techniques are crucial to improving patient outcomes; animal models are especially valuable in this regard. Currently, the creation of animal models of fractures involves cutting to avoid lethal pleural injury and induce linear fractures incompatible with real-world morphology. Suitable models with bone displacement, which are common surgical targets, are limited. Therefore, we aimed to develop an animal experimental model that aligns with real-world clinical conditions and allows for more in-depth research on blunt chest trauma.

We conducted an animal study using New Zealand rabbits to create fractures with displacement, without injuring the pleura. A facial bone drill was used to create several fracture holes in the ribs that were carefully dissected using a rongeur and scissors. After reaching the border between the bone and pleura, they were separated through blunt dissection with scissors. Fractures were created without injuring the pleura, and a rongeur was used to displace the bones.

Seven rabbits successfully underwent surgery, with each awakening without pleural injury and pneumothorax. Surgery effectiveness was primarily assessed using chest computed tomography (CT) to evaluate types of rib fractures. CT was performed in the second week and second and third months postoperatively. All rabbits exhibited visibly displaced rib fractures, and no additional chest complications were observed.

This innovative animal model allowed us to study pathophysiological changes following rib fracture. Future studies investigating new medical materials and surgical procedures will benefit from this animal model.