A Novel Rat Model of Intramedullary Tibia Fracture Fixation Using Polyetheretherketone Threaded Rod

BACKGROUND: The rat fracture fixation models have been widely adopted, but current implant designs suffer from operational difficulty, massive soft-tissue dissection, and radiological intervention. The authors developed a new tibia fracture-healing model using minor invasive intramedullary fixations with polyetheretherketone (PEEK) threaded rods, which have excellent x-ray translucency and no magnetic resonance artifact. METHODS: Tibia fractures of 6 adult male Sprague-Dawley rats were fixed with intramedullary PEEK threaded rods. X-ray examination was performed at 0, 4, and 8 weeks postoperatively. Histological analysis was conducted via hematoxylin-eosin staining of nondecalcified tissue sections. RESULTS: Radiological fracture healing was observed at 8 weeks postoperatively. Histology demonstrated fracture gap bridging and bone ingrowth adjacent to PEEK. CONCLUSION: This innovative model is simple and effective, providing a new selection in future biomedical research.