A senior high school student suffered a sudden right hip pain while running.
Right hip ROM was marked limited with severe pain. Palpable of the right hip also revealed a severe tender area.
Here was his pelvic radiography
Avulsion fracture of the Anterior Superior Iliac Spine (ASIS) was identified.
Tendons are much more stronger than muscles for any cross-sectional area. When a sudden strain is applied to a muscle-tendon-bone unit, the muscle will rupture, or the tendon will avulse at its insertion, together with a fragment of bone to which it is attached.
The most common avulsion fractures of the pelvis and its related muslce attachement are (Figure)
1. ASIS -- Sartorius muscle
2. AIIS -- Rectus femoris muscle
3. Ischial tuberosity -- Hamstring muscles
4. Lesser tuberosity -- iliopsoas muslce
References:
1. Fernbarch, Wilkonson RH. Avulsion injuries of the pelvis and proximal femur. Am J Roentgenol 1981; 137:581-4
2. M Naude, Lindeque, Rensburg. Avulsion fractures of the pelvis. Sports Medicine. June 2003.
