Anterior Superior Iliac Spine (ASIS) Avulsion

Topic updated on 05/03/15 5:33pm
  • ASIS avulsions occur in young athletes through the physis
  • Mechanism
    • result from indirect trauma
    • caused by sudden and forceful contraction of sartorius and tensor fascia lata
    • occurs during hip extension (sprinting or swinging a baseball bat)
  • Muscles that originate from ASIS 
    • sartorius (femoral n.) 
    • tensor fascia lata (superior gluteal n.) 
  • History
    • athlete will often report a pop or snap at the time of injury
  • Symptoms
    • may complain of weakness
      • may be confused or misdiagnosed as an acute muscle strain
  • Physical exam
    • may see weakness to hip flexion and knee extension
    • severe injuries may result in a limp
  • Radiographs
    • displaced fractures usually can be seen on radiographs
      • may be missed due to location and small size of bony fragment 
  • CT or MRI
    • can be obtained to confirm the diagnosis
  • Nonoperative
    • rest, protected weight bearing with crutches, and early ROM and stretching   
      • indications
        • most cases
  • Operative
    • ORIF of avulsion fracture
      • indications
        • fractures with displacement of > 3 cm
        • painful nonunions


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Qbank (4 Questions)

(SBQ07.42) A 14-year-old male sprinter felt a pop and began to experience immediate left hip pain while participating in the 400-meter dash. Upon evaluation, he has difficulty bearing weight due to left hip pain and has tenderness to palpation superior to his left hip joint. Imaging of the pelvis is included in Figure A. Treatment should should include: Topic Review Topic
FIGURES: A          

1. Fixation of the femoral neck stress fracture
2. Recession of the iliopsoas to releive internal snapping hip syndrome
3. Fixation of the sartorius origin
4. Fixation of the direct of head of rectus femoris origin
5. Progressive weightbearing with return to activities when pain free motion achieved

(OBQ12.61) A 12-year-old male has immediate pain and echhymosis over his right groin after injuring himself during a hockey game. His radiograph is shown in figure A. Which of the following statements is true regarding the insertion of his injured muscle? Topic Review Topic
FIGURES: A          

1. Inserts on fibular head
2. Insertion on femur is anterior and distal to lateral collateral ligament of knee
3. Can be source of pes anserinus bursitis
4. Tendon is a harvest option for autograft ACL reconstruction
5. Extends the hip and flexes the knee

(OBQ06.38) An avulsion fracture of the anterior superior iliac spine (ASIS) in a adolescent athlete often occurs from forceful eccentric contraction of which of the following muscles? Topic Review Topic

1. External oblique
2. Rectus femoris
3. Iliopsoas
4. Sartorius
5. Gluteus medius

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