Pediatric Pelvis and Hip Apophyseal Avulsion Fracture

  • Etiology: forceful and repetitive contractions of attaching muscles at apophyses, avulsion of insertion of muscle leads to avulsion fracture
  • Imaging:
    — Ischial tuberosity avulsion (54%) due to hamstrings adductors insertion
    — Anterior inferior iliac spine avulsion (22%) due to rectus femoris muscle insertion
    — Anterior superior iliac spine avulsion (19%) due to sartorius muscle insertion
    — Pubic symphysis avulsion (3%) – superior due to rectus abdominis muscle insertion, inferior due to adductor group insertion
    — Iliac crest avulsion (1%) due to transverse and oblique abdominal muscles insertion
    — Greater trochanter avulsion due to gluteal muscle insertion
    — Lesser trochanter avulsion (<1%) due to iliopsoas muscle insertion
  • Clinical: avulsion and iliac wing fractures are more common than acetabular fractures and SI joint malalignment

Radiology Cases of Pelvis and Hip Apophyseal Avulsion Fracture

Radiograph of avulsion of the lessor trochanter
AP radiograph of the pelvis shows avulsion of the apophysis of the right lesser trochanter.