Animal models in bone repair

Animal models in fracture repair comprise different species and a numerous variety of fixation devices. There are no standardized models around making comparisons between studies difficult. In recent years molecular mechanisms of fracture repair are investigated mainly in genetically modified mice and also in rats using biomimetic agents to accelerate fracture repair, but translation to clinical use is not yet available. In this update species relevant questions are addressed from the experienced personal view of the author as well as practical implementations for accurate study designs and animal welfare issues.