Creation of a Tibia Extension Model With a Perforated Ilizarov Ring System: An Experimental Study in Rats

Distraction osteogenesis is a valuable clinical technique used to address length discrepancies in long bone deformities. This procedure involves performing an osteotomy at an appropriate site in the bone and correcting the deformity through an extension system. This research aims to investigate the efficacy of a newly developed device for use in rat tibias and to provide an alternative to existing devices used in animal experiments. A total of 16 male Wistar-Albino rats, each weighing approximately 300-350 grams and aged 20-28 weeks, were used in the study. On the first day, a fixator was applied to the right tibias of the rats, and Ilizarov osteotomy was performed. Distraction of the tibia commenced on the Day 7. During the distraction phase, which lasted seven days, tibia lengthening was performed twice daily at 08:00 and 16:00, with each session involving a distraction of 0.25 mm. After a 14-day waiting period, evaluations were conducted on the 28th, 35th, 42nd, and 49th days post-surgery. Following these assessments, the rats were evaluated with X-rays and subsequently sacrificed. The distraction procedures proceeded largely without issues in the rats. Union was observed during the follow-up after distraction. In the initial postoperative X-ray of one rat, no problems with the reduction of the osteotomy were detected. To verify the functionality of the system, acute distraction was tested in one rat model, and successful elongation was achieved. However, one rat experienced circulatory disturbances post-operation, with the extremity showing an ecchymotic appearance. The extremity returned to its normal state during follow-up. Infection occurred in three rats. No postoperative antibiotic therapy was administered to any of the rat models. During follow-up, the infections resolved with regular dressing changes. Due to fewer complications and improved radiological imaging with the extension models performed in the metaphyseal region of rat tibias, our system could be utilized in future fracture model applications or distraction osteogenesis studies involving rat models. We believe it could serve as an alternative to other models for creating extension models at a lower cost.