Clinical anatomy of the meniscus in animal models: pros and cons.

Nowadays, despite the possibility to use in vitro or computer models in research, animal models are still essential. Different animal models are available for meniscal repair investigation. Although a unique perfect model for the structure of the human's knee does not exist, the choice of the proper animal model is crucial for a correct research. The principal animal models in the meniscal repair are sheep, goats, pigs and dogs. Each of these has pros and cons for their utilization. Analysing each pro and con is essential for optimizing the choice of the animal model, which depends on the experimental question, avoiding unnecessary waste of resources and minimizing the animal suffering, according to the Russell and Burch's three "Rs" principles (Reduce, Refine and Recycle). In this concise review, we resume the meniscus anatomical features of the main large animals, to help choose the most suitable animal model for subsequent studies on meniscal repair.