Imaging Case of the Week 84

The following pelvic x-ray is from a 15 year old male. He was running when he heard a ‘pop’ sound and collapsed onto the ground, following which he noted pain around the right groin and down to the knee. What can you note in the x-ray?

pelvic x-ray

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[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]

The pelvic x-ray shows right ASIS (anterior superior iliac spine) avulsion fracture. There is a triangular bony density adjacent to the anterior superior iliac spine on the right. This is indicative of avulsion at the attachment of the sartorius muscle.

ASIS avulsion

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This patient was managed conservatively.

ASIS avulsion:

  • Commonly involves young athletes.
  • Occurs due to sudden forceful contraction of the sartorius and the tensor fascia lata.
  • Patient will often report a ‘pop’ at the time of injury.
  • Most cases managed conservatively with rest, crutches, analgesia and early weight bearing.
  • Operative indications: fractures with >3mm displacement and painful non-unions.