What are two important signs indicating a fracture in a bone?

The indicators of a fracture need to provide clear signs that there has been a disruption to the integrity of the bone. Deformity and shortening of a limb are strong signs of a fracture because they suggest that an abnormality in the alignment of the bone has occurred. When a fracture happens, bones may not only break but can shift out of place, leading to visible deformities. Shortening of the limb could also result from a fractured bone segment that has been displaced or improperly aligned.

While other signs like pain and swelling, discoloration and tenderness, or heat and loss of function are relevant in evaluating an injury, they can also be present in other conditions such as sprains or soft tissue injuries. Thus, deformity and shortening specifically point toward the likelihood of a fracture due to the significant changes in bone structure, making this the most definitive pair of signs among the choices provided.