Bone Repair

Introduction

• Bone repair is necessary due to damage or fractures.
• Fractures: breaks in bones caused by trauma (youth) or bone weakening (age-related).

Classification of Fractures

1. Position of Bone
   • Non-displaced: Bone ends retain normal position.
   • Displaced: Bone ends out of alignment.
2. Completeness of Break
   • Complete: Bone broken all the way through.
   • Incomplete: Bone not broken all the way through.
3. Skin Penetration
   • Open (Compound): Skin surface penetrated by bone.
   • Closed (Simple): Skin surface not penetrated.

Additional Classification

• Based on location, external appearance, and nature of the break.

Common Types of Fractures

• Comminuted: Bone fragments into pieces (common in brittle bones).
• Compression: Bone crushed (common in porous bones).
• Spiral: Fracture spirals around bone (common in sports injuries).
• Epiphyseal: Separation at epiphyseal plate common in children.
• Depressed: Bone pressed inward (common in skull fractures).
• Greenstick: Bone breaks incompletely (common in children).

Treatment of Bone Fractures

• Closed Reduction: Manipulation to correct position.
• Open Reduction: Surgical pins/wires to secure bone.
• Immobilization: Use of casts or traction.
• Healing time varies by severity, age, and bone involved.

Stages of Bone Fracture Repair

1. Hematoma Formation
   • Blood clot forms at fracture site.
   • Inflammation and new growth factors occur.
2. Fibrocartilaginous Callus
   • New capillaries grow into hematoma.
   • Fibroblasts and new cartilaginous matrix form.
3. Bony Callus Formation
   • Conversion of fibrocartilaginous callus to spongy bone.
   • Occurs over 2 months.
4. Bone Remodeling
   • Excess material removed, compact bone laid down.
   • Final structure resembles original bone.

Developmental Aspects of Bone

• Ossification Timing: Predictable; determines fetal development stage.
• Birth to Young Adulthood: Most bones ossified by age 25.
• Age-Related Changes
  • In children, bone formation exceeds resorption.
  • In adults, bone resorption exceeds formation.
  • Prevention of resorption: Adequate diet, prevent inflammation, regular use of bones.

Bone Density and Osteoporosis

• Bone density changes determined by genetics.
• Vitamin D and calcium critical for bone health.
• Greater risk of osteoporosis in white females, especially with inadequate diet.

Summary

• Remember the four major steps of bone repair.
• Continuous bone remodeling throughout life.
• Importance of nutrition and activity in maintaining bone health.