70 Bone Fracture – Factors that affect Healing

There are many factors (local and systemic) that affect both the speed and the extent of healing of bone fractures.

Local Factors:

• Amount of local damage: Smaller areas of damage heal faster than larger areas.
• Proximity of bone ends: Fractured bone ends that are closer to each other heal faster and better. Treatment that involves reduction (e.g., casts, pins, plates, wires, etc.) reduced the gap between bone ends and facilitates healing.
• Presence of foreign material or infection: Slows down healing. Cleaning of the wound and applying sterile dressings is recommended.
• Infection: Septic (infected) vs. aseptic (sterile) conditions affect healing. In addition to cleaning of the wound, prophylactic antibiotics may be used to prevent serious infection and further damage that can be caused by microbes.
• Bone graft acceptance: Determines healing speed. Most often autologous bone (from the person’s own ilium, ribs or fibula) is used to ensure acceptance.
• Blood supply: Better blood supply (and therefore access to nutrients and oxygen) facilitates faster healing, particularly as mitosis requires the uptake of building blocks (e.g., amino acids), fuel molecules (e.g., glucose and lipids), and growth-stimulating hormones from plasma (e.g., growth hormone, insulin, thyroid hormone).
• Extent of osteonecrosis: (or bone cell death) affects healing.
• Inflammation and edema if extensive can lead to hypoxia and slow healing.
• Blood clots and embolisms: Block blood flow, slowing healing.
• Radiation therapy: Causes bone marrow depression (reduced rate of RBC and WBC proliferation), hindering healing.

Systemic Factors:

• Age: Old age correlates with longer healing time.
• Access to Nutrition: Good nutrition speeds up healing.
• Circulatory problems: Impede blood flow and healing.
• Diabetes: Causes vascular damage and circulatory problems reducing blood supply, leading to slower healing.
• Anemia: Reduces oxygen carrying capacity, slowing healing.
• Rheumatoid arthritis: Autoimmune condition and immunosuppressant use delay healing.
• Glucocorticoid use: Slows healing due to catabolic effects.