A 10-Year-Old Boy Who Twisted His Knee in the Backyard

Differential Diagnosis

• Anterior cruciate ligament tear
• Dislocation
• Displaced avulsion fracture of the tibial spine
• Meniscal tear

Diagnosis

The image shows oval-shaped bone density projecting in the intercondylar notch region. This is a displaced avulsion fracture of the tibial spine, also known as a tibial eminence fracture or ACL avulsion fracture.

Learnings

• ACL avulsion fractures are often associated with sports or other vigorous physical activity in children 8─13 years of age
• The fracture occurs secondary to relative weakness of incompletely ossified tibial eminence compared to native ACL fibers

Pearls for Urgent Care Management

• Evaluate and document neurovascular status
• Evaluate for more serious considerations such as open fracture, compartment syndrome, or fracture/dislocation in the proximal or distal joint
• Pain medication should be administered, with consideration to potential emergent surgical repair which would require NPO status
• The knee should be immobilized prior to transfer

Acknowledgment: Images and case provided by Experity Teleradiology (www.experityhealth.com/teleradiology).