Development and validation of a modularized external fixator for generating standardized fracture healing micromotions in rats

Bone & Joint Research

article

Weichen Qi¹  Xiaoreng Feng¹  Teng Zhang¹  Hao Wu¹  Christian Fang²  Frankie Leung² 

[1] Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong;Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong

关键词: Design for experiments;    Surgical instruments;    In vivo;    Medical treatment;    Small animal model;    Bone fracture;    Bone healing model;    fracture healing;    rat models;    external fixators;    strain;    fractured femora;    fracture sites;    animal models;    stiffness;    femora;    body weight;   

DOI  :  10.1302/2046-3758.1011.BJR-2021-0028.R1

学科分类：骨科学

来源: British Editorial Society Of Bone And Joint Surgery

【 摘 要 】

AimsTo fully verify the reliability and reproducibility of an experimental method in generating standardized micromotion for the rat femur fracture model.MethodsA modularized experimental device has been developed that allows rat models to be used instead of large animal models, with the aim of reducing systematic errors and time and money constraints on grouping. The bench test was used to determine the difference between the measured and set values of the micromotion produced by this device under different simulated loading weights. The displacement of the fixator under different loading conditions was measured by compression tests, which was used to simulate the unexpected micromotion caused by the rat’s ambulation. In vivo preliminary experiments with a small sample size were used to test the feasibility and effectiveness of the whole experimental scheme and surgical scheme.ResultsThe bench test showed that a weight loading < 500 g did not affect the operation of experimental device. The compression test demonstrated that the stiffness of the device was sufficient to keep the uncontrollable motion between fracture ends, resulting from the rat’s daily activities, within 1% strain. In vivo results on 15 rats prove that the device works reliably, without overburdening the experimental animals, and provides standardized micromotion reproductively at the fracture site according to the set parameters.ConclusionOur device was able to investigate the effect of micromotion parameters on fracture healing by generating standardized micromotion to small animal models.

【 授权许可】

CC BY-NC