An anterior inferior iliac spine (AIIS) avulsion is an apophyseal avulsion injury seen in adolescent athletes as a result of eccentric contraction of the rectus femoris. Diagnosis is made with pelvis radiographs that shows an avulsion off the AIIS.
https://www.orthobullets.com/knee-and-sports/3131/anterior-inferior-iliac-spine-avulsion-aiis

