What type of fracture occurs when a break displaces a portion of bone from its usual position?

An avulsion fracture occurs when a fragment of bone is displaced at the site of tendon or ligament attachment due to a strong pull or tension. In this type of fracture, the bone itself remains largely intact, but a piece of it is pulled away, resulting in a separation from its usual position. This can happen during activities that involve sudden or forceful muscle contractions, often seen in sports.

The other types of fractures, while they involve breaks in the bone, do not specifically describe the displacement of a portion of the bone from its original location. A comminuted fracture typically involves the bone breaking into multiple pieces, a greenstick fracture is characterized by an incomplete break commonly seen in children, and an impact fracture occurs when one bone is driven into another. These classifications do not focus on the displacement aspect as seen in avulsion fractures.