Scientific basis for bilateral animal models in orthopaedics

(1) Bilateral procedures should be used when weight-bearing is an experimental parameter that should be controlled. (2) Bilateral procedures should be used for biocompatibility in osseous tissue and in fact most tissues according to ASTM. (3) Bilateral models in orthopaedics allow a more objective evaluation and characterization of materials and implants, reducing statistical and biological variables by an order of magnitude. Thus, this experimental approach increases the statistical significance of a study with a smaller number of animals.