A 40-Year-Old with Back Pain After a Fall

Differential Diagnosis

• Accessory ossicle
• Unfused ossification center
• Avulsion fracture of the anterior inferior iliac spine

Diagnosis

The image shows an irregular crescentic fragment adjacent to the anterior inferior iliac spine (bone donor site). The correct diagnosis is an avulsion fracture, anterior inferior iliac spine.

Learnings/What to Look for

• Typically, pelvic and hip apophyseal injuries occur in the 14- to 25-year age range
• Usually kicking sports such as soccer are involved, though such injuries are also seen in gymnasts and athletes who engage in jumping sports (such as in track and field)
• Anterior inferior iliac spine avulsion fractures are commonly the result of sudden contraction of the rectus femoris

Pearls for Urgent Care Management

• Treatment is most often nonoperative and includes initial bedrest, ice, and activity modification
• Hip flexed for 2 weeks with the position lessening stretch of the rectus femoris muscle and apophysis
• Follow with guarded weightbearing for 4 weeks and careful return to activity as full recovery may take 4 months

Acknowledgment: Image and case presented by Experity Teleradiology (www.experiety.com/teleradiology).