Which phase is characterized by mature and strong collagen fibers?

• A. Weeks 5-10
• B. Weeks 10+
• C. Week 1
• D. Weeks 2-4

Answer: (B)

During healing, the tissue goes through a remodeling phase where collagen fibers mature and align to handle load. In the early inflammatory and proliferative phases, collagen is mainly type III, laid down in a loose, disorganized mesh, so its strength is still low. In remodeling, fibroblasts replace much of the type III with type I collagen, fibers become highly cross-linked, and they reorganize along the lines of mechanical stress. This process gradually increases tensile strength and durability, and it extends well beyond the initial weeks. Therefore, mature and strong collagen fibers are most characteristic of the remodeling phase, which corresponds to the later time frame—around weeks 10 and beyond.