Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Homburg/Saar, Germany.
Bone. 2011 Oct;49(4):591-9. doi: 10.1016/j.bone.2011.07.007. Epub 2011 Jul 19.
Small animal fracture models have gained increasing interest in fracture healing studies. To achieve standardized and defined study conditions, various variables must be carefully controlled when designing fracture healing experiments in mice or rats. The strain, age and sex of the animals may influence the process of fracture healing. Furthermore, the choice of the fracture fixation technique depends on the questions addressed, whereby intra- and extramedullary implants as well as open and closed surgical approaches may be considered. During the last few years, a variety of different, highly sophisticated implants for fracture fixation in small animals have been developed. Rigid fixation with locking plates or external fixators results in predominantly intramembranous healing in both mice and rats. Locking plates, external fixators, intramedullary screws, the locking nail and the pin-clip device allow different degrees of stability resulting in various amounts of endochondral and intramembranous healing. The use of common pins that do not provide rotational and axial stability during fracture stabilization should be discouraged in the future. Analyses should include at least biomechanical and histological evaluations, even if the focus of the study is directed towards the elucidation of molecular mechanisms of fracture healing using the largely available spectrum of antibodies and gene-targeted animals to study molecular mechanisms of fracture healing. This review discusses distinct requirements for the experimental setups as well as the advantages and pitfalls of the different fixation techniques in rats and mice.
小动物骨折模型在骨折愈合研究中越来越受到关注。为了实现标准化和定义明确的研究条件，在设计小鼠或大鼠骨折愈合实验时，必须仔细控制各种变量。动物的品系、年龄和性别可能会影响骨折愈合的过程。此外，骨折固定技术的选择取决于要解决的问题，其中可以考虑髓内和髓外植入物以及开放式和闭合式手术方法。在过去几年中，已经开发出了多种不同的、高度复杂的小动物骨折固定植入物。在小鼠和大鼠中，使用锁定板或外固定器进行刚性固定主要导致膜内愈合。锁定板、外固定器、髓内钉、锁定钉和钉夹装置允许不同程度的稳定性，从而导致不同程度的软骨内和膜内愈合。未来应避免使用在骨折稳定过程中不能提供旋转和轴向稳定性的普通销钉。分析应至少包括生物力学和组织学评估，即使研究的重点是使用大量可用的抗体和基因靶向动物来阐明骨折愈合的分子机制，以研究骨折愈合的分子机制。这篇综述讨论了实验设置的不同要求，以及在大鼠和小鼠中使用不同固定技术的优缺点。
