INTRODUCTION Chondrogenesis is a common sign of tendinopathy,especially in athletes,but the mechanism of chondrogenesis in tendon,or the metaplasia from tendon tissue to chondrogenic tissue remains unclear.There have been a variety of models,ranging from in vitro to in vivo to allow for studying tendinopathy,however,no studies to date have reported a tendinopathy model characterized with chondrogenesis.An appropriate model of chondrogenic tendinopathy is essential to studying the regulation of abnormal chondrogenesis in the affected tendons.