Separation of the anterior part of the left iliac crest apophysis compared to the asymptomatic right side is consistent with avulsion injury.
Most frequent sites of pelvic apophyseal avulsion fractures are following.
1) iliac crest: insertions of the abdominal muscle, the tensor of fascia lata and of the gluteus medius
2) anterior superior iliac spine: insertion of sartorius
3) anterior inferior iliac spine: insertion of rectus femoris
4) superior corner of pubic symphysis: insertion of rectus abdominis
5) ischial tuberosity: insertion of hamstring muscles
6) lesser trochanter of the femur: insertion of iliopsoas muscle
