Which fracture is defined as one bone fragment pushed into another?

• A. Impacted fracture
• B. Compression fracture
• C. Open fracture
• D. Depressed fracture

Answer: (A)

When one bone fragment is driven into another along the axis of the bone, the resulting fracture is called an impacted fracture. This happens under a compressive or axial load, such as a fall onto an outstretched hand, causing the ends of the bone to telescope into each other. Radiographs may show the ends overlapped or shortened, but the fracture line itself can be subtle because the pieces are pressed together rather than simply broken apart.

This differs from an open fracture, where the bone breaks through the skin; a depressed fracture, where bone is pushed inward (often seen in the skull); and a compression fracture, which is a crushing of bone along its length (as in vertebrae). The defining feature here is the fragment being driven into another fragment.