In fracture callus, which is commonly present?

• A. Absence of osteoclasts
• B. No remodeling
• C. Osteoclasts and resorption lacunae present (bone remodeling)
• D. Dense fibrous tissue only

Answer: (C)

Fracture healing involves a remodeling phase where woven bone formed in the callus is gradually replaced by lamellar bone. During this process osteoclasts come in to resorb bone and create resorption lacunae, while osteoblasts lay down new bone. The presence of osteoclasts and resorption lacunae signals that remodeling is actively occurring, which is a normal and common aspect of fracture callus maturation. If osteoclasts were absent or remodeling didn’t happen, you’d not see replacement of the callus with mature bone, which is not typical in a normally healing fracture. Dense fibrous tissue alone would not account for the active remodeling seen in a typical fracture callus.