Which tissue forms the cartilaginous callus during bone healing?

• A. Fibrocartilage
• B. Fibrous Tissue
• C. Hyaline Cartilage
• D. Bone Tissue

Answer: (A)

During bone healing, the bridge that forms between fracture ends is a soft callus made mainly of fibrocartilage. This happens because cells from the periosteum and endosteum differentiate into fibroblasts and chondroblasts, producing a matrix rich in collagen and cartilage. The result is a fibrocartilaginous tissue that spans the fracture and provides stability while still allowing some flexibility. This provisional tissue lays down a scaffold for later bone formation, as endochondral ossification gradually replaces the cartilage with woven bone to create the hard callus. Hyaline cartilage is more typical of joints and growth plates, not the fracture callus, and bone tissue itself isn’t the initial cartilaginous bridge.