Which injury type is characterized by swelling, pain, and deformed limb without open skin?

The correct answer is a closed fracture. A closed fracture is a type of bone injury where the bone breaks but does not penetrate the skin, which means there is no open wound present. This condition is often accompanied by swelling, significant pain, and visible deformity in the affected limb, as the broken bone can create a disruption in the normal alignment of the limb.

The symptoms of swelling and pain reflect the body's natural response to injury, involving inflammation and increased blood flow to the area. The deformity arises because the break can cause the limb to look misaligned if viewed from a certain angle. In the case of a closed fracture, the integrity of the skin remains intact, distinguishing it from an open fracture, where the broken bone protrudes through the skin.

A sprain involves stretching or tearing of ligaments and does not usually result in deformity of the limb. A dislocation occurs when bones at a joint are displaced, which can also result in deformity but typically involves the joint rather than a bone break. Therefore, the combination of swelling, pain, and a deformed limb without any broken skin is characteristic of a closed fracture.