Which term describes an injury involving a sharp object penetrating the skin?

The term that describes an injury involving a sharp object penetrating the skin is "puncture." A puncture wound occurs when a pointed object, such as a nail or a knife, impales the skin and creates a small but deep wound. This type of injury can be serious, as it may damage underlying tissues and introduce bacteria, increasing the risk of infection. Puncture wounds often require careful medical evaluation and treatment to ensure proper healing and to prevent complications.

In contrast, a contusion refers to a bruise caused by blunt force trauma that damages small blood vessels and causes bleeding under the skin without breaking the skin's surface. A fracture, on the other hand, involves the breaking of a bone, and a sprain is an injury to a ligament resulting from overstretching or tearing. Each of these terms describes different types of injuries that do not involve the specific action of a sharp object penetrating the skin, further highlighting why "puncture" is the most accurate choice here.