An avulsion fracture of the left anterior superior iliac spine is most likely in which scenario?

• A. A 13-year-old basketball player who experienced a forceful contraction of the sartorius
• B. A 14-year-old soccer player who experienced a forceful contraction of the rectus femoris
• C. A 22-year-old sprinter who experienced a forceful contraction of the hamstrings
• D. A 40-year-old hockey player who experienced a direct blow to the ilium

Answer: (A)

When a bone fragment comes off at a tendon insertion, it’s usually because a strong, rapid muscle contraction is pulling on a still-developing growth area. The sartorius originates at the anterior superior iliac spine (ASIS), and in adolescents the apophysis there is still weak compared to the tendon tension. A sudden, forceful contraction of the sartorius—such as during sprinting or a powerful leg pull in a sport like basketball—can avulse the ASIS, producing an ASIS fracture.

The scenario fits this pattern: a 13-year-old basketball player experiences a forceful contraction of the sartorius, making an ASIS avulsion the most likely injury. The other options don’t align with the ASIS specifically: forcing contraction of the rectus femoris would typically involve the AIIS (not the ASIS); a hamstring surge in a young adult tends to injure the ischial tuberosity or produce a different strain, and a direct blow to the ilium in an older athlete is more likely to cause a general pelvic fracture rather than an isolated ASIS avulsion.