Critical-Size Defects of Animal Models for Bone Regeneration

Animal models have been extensively used and have contributed greatly to the development and establishment of a wide range of translational approaches aiming to regenerate the bone tissue. Accordingly, this paper presents a review of the critical-size defects (CSDs) of animal models for bone repair and contributes to determine which defect dimensions could be considered as being critical size. Recent work involving the definition of CSDs, CSDs related animal models for bone regeneration, and an overview of the evaluation of bone regeneration in the critical size defects has been summarized and reviewed. A systematic review were conducted to provide prerequisite data for establishing bone critical size defect model in different animals and evaluating bone materials using these models and guide future clinical trials of bone tissue engineering, more importantly, determine the estimates and the effect for guiding future human clinical trials. Also, there is a necessity for further standardization of the animal models to enable more accurate comparison among future studies.