Final answer:
An external callus is a raised portion of bone tissue that forms on the outer surface of a healed fracture, which might remain slightly swollen after the bone has undergone remodeling.
Step-by-step explanation:
A raised portion of osseous tissue on the outside of a healed fracture is called an external callus. During the healing process, chondrocytes and osteoblasts create this external callus of hyaline cartilage and bone around the break to stabilize the fracture. As healing progresses, compact bone replaces the spongy bone at the outer edges, and the external callus may reduce in size after remodeling. However, a slight swelling might remain at the former fracture site.