Avulsion Fractures of the Anterior Inferior Iliac Spine (AIIS)

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Avulsion fractures occur when a small piece of bone is separated from the main bone due to the pull of the muscle and tendon attached to it. This usually occurs in growing bone, which is weaker than mature bone. In the hip, this often occurs at the anterior inferior iliac spine (AIIS). This is the bony part of the pelvis where one of the thigh (quadricep) muscles attaches, known as the rectus femoris. The rectus femoris is key to bending the hip and knee.

Signs and Symptoms

  • Swollen or tender area along the front of the hip
  • Pain with walking and often walking with a limp
  • Bruising in the upper thigh after injury
  • Weakness when lifting the leg
  • Pain with activity like forceful bending of the hip or extending of the knee (kicking)
  • Pop heard at the time of injury

Increased Risk

  • Sports that require kicking (soccer, football, gymnastics)
  • Poor warm-up before practice or play
  • Poor physical conditioning (strength and flexibility)
  • Previous thigh, knee, or pelvis injury

Treatment

Medicine

  • Anti-inflammatory medicines, like ibuprofen (Motrin® or Advil®) or naproxen (Aleve®) may be recommended. Take these as directed by your doctor or health care provider.
  • Other minor pain relievers, such as acetaminophen (Tylenol®) may be taken.

Use of Cold and Heat 

  • Cold should be applied for 10 to 15 minutes every 2 to 3 hours and after any activity that makes symptoms worse. Use ice packs or an ice massage and raise the foot and ankle at or above heart level to reduce swelling.
  • Heat may be used before doing stretching and strengthening activities prescribed by your doctor, health care provider, or athletic trainer. Use a heat pack or a warm soak. Apply for 10 to 15 minutes.

Orthopedic Aids

  • Crutches may be used to help with limping and pain for 2 to 4 weeks.

Exercises

  • Exercises to stretch and improve the strength and flexibility of the hip are helpful. These can be done at home, but often a referral to a physical therapist or athletic trainer may be advised by your doctor or health care provider.

How to Prevent

  • Do correct warm-up and stretch before practice or competition
  • Maintain proper conditioning, strength, endurance, cardiovascular fitness, and flexibility of the hip

When to Call the Doctor

Call your doctor, health care provider, or the Sports Medicine team at (614) 355-6000 if:

  • Symptoms get worse or do not improve in 4 weeks, even with treatment.
  • New, unexplained symptoms develop.