Imaging Case of the Week 466 Answer

The left hip x-ray shows an avulsion fracture of the ischial tuberosity.

The x-ray findings were confirmed with an MRI scan and the fracture was managed conservatively by the specialist.

The ischial tuberosity is where the hamstring group of muscles originate. Ischial avulsion fractures are associated with forceful flexion of the hip with the knee extended. They are more commonly seen in skeletally immature individuals.

It is mostly managed conservatively. However, avulsions with more than 2cm displacement may need ORIF and specialist opinion should be sought.

Complications, in addition to chronic pain and hamstring weakness, include sciatic nerve injury due to the scarring of the nerve which runs between the ischium and greater trochanter and non-union. Exuberant callus formation during healing may mimic a soft tissue tumor.

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