A sign of an extremity fracture includes which of the following?

Swelling and crepitus under the skin are strong indications of an extremity fracture. When a fracture occurs, the surrounding tissues can become inflamed and swollen due to the body's natural response to injury. Crepitus, which refers to the grating or popping sensation felt when the bone fragments move against each other or when air bubbles are present, is a clear sign that something is wrong within the limb. These symptoms are particularly concerning in the context of a fracture, as they indicate disruptiveness and potential damage to the structures in the area of the injury.

Other signs of an extremity fracture can include limited range of motion and skin discoloration. However, swelling and crepitus are more definitive signs, as they directly relate to the fracture itself and the immediate physiological response to the injury. Greenstick pain, while relevant in the context of certain types of fractures (especially in children), is not universally applicable and does not capture the full scope of symptoms associated with a fracture. Therefore, swelling and crepitus under the skin serve as clearer indicators that an extremity fracture has likely occurred.