Fractures

Fractures

  • Definition: A fracture is a break in a bone.

  • Types of Fractures:

    • Open (Compound) Fracture: Bone ends protrude through the skin. (The bone breaks and sticks out through the skin.)

    • Closed (Simple) Fracture: Bone does not break the skin. (The bone is broken but stays inside the skin.)

    • Comminuted Fracture: Bone is splintered or broken into multiple pieces. (The bone is in many small pieces.)

    • Greenstick Fracture: Partial fracture in children, one side breaks while the other bends. (The bone bends like a stick that’s not fully broken.)

    • Impacted Fracture: One end of a fractured bone is driven into another. (One piece of bone gets pushed into another piece.)

    • Epiphysial Fracture: Involves the epiphysial plate in a growing individual - can result in shorter bones. (A special part of the bone for growing gets hurt, which might make the bone shorter.)

Fracture Repair Phases

  • Phase 1: Reactive Phase

    • Blood vessels break, leading to blood leakage and formation of a fracture hematoma within 6-8 hours. (When a bone breaks, blood leaks out and makes a bruise around the break.)

    • Dead bone cells result in swelling and inflammation; phagocytes and osteoclasts remove damaged tissue. (The body sends help to clean up the hurt area.)

  • Phase 2: Reparative Phase

    • Formation of fibrocartilaginous callus: blood vessels grow into hematoma, fibroblasts produce collagen, and chondroblasts generate fibrocartilage. (New tissue forms to connect the broken pieces together.)

    • This bridging mass of repair tissue takes about 3 weeks to form. (It takes about 3 weeks for the bridge of new tissue to grow.)

  • Phase 3: Operative Phase

    • Formation of bony callus: osteoprogenitor cells develop into osteoblasts producing spongy bone trabeculae. (The new tissue hardens and turns into real bone.)

    • Fibrocartilage is converted into spongy bone, lasting about 3-4 months. (The soft tissue becomes strong bone over a few months.)

  • Phase 4: Remodeling Phase

    • Osteoclasts reabsorb dead bone fragments, compact bone replaces spongy bone at the fracture periphery. (Old, broken pieces of bone are cleaned up, and strong bone grows around the break.)

    • Bone returns to original shape through remodeling processes. (The bone gets reshaped to look like it did before the break.)