2. Definition:-
• US FDA defines non union as “ established when a minimum of 9
months has elapsed since injury and fracture shows no visible
progressive signs of healing for 3 months.”
• Brinker defined non union as a fracture that, in the opinion of treating
physician has no possibility of healing without further intervention.”
3. Etiology and pathophysiology:-
• Fractures treated non-operatively and those treated with IMIL nails,
bridge plate and many external fixators rely upon SECONDARY BONE
HEALING.
• Relative Stability is provided by these devices to obtain Secondary
bone healing.
• Fracture heal with callus formation and progress through stages of
• Inflammatory stage
• Soft callus stage
• Hard callus stage
• remodelling phase
4. • Fractures fixed rigidly with plates rely on PRIMARY BONE HEALING.
• Absolute Stability is necessary.
• Healing is similar to remodelling phase of secondary bone healing
with osteoclasts converting woven bone to lamellar bone.
•
5. • Etiology of non union may be mechanical or biological.
• Biological etiology are further classified into LOCAL or SYSTEMIC.
6. LOCAL CAUSES:-
• Extensive soft tissue stripping ( by surgeon or injury)
• Bone loss
• Vascular injury
• Radiation
• Infection
7. Systemic Causes:-
• Age
• Chronic Diseases like Diabetes mellitus
• Anemia
• Metabolic or Endocrine Abnormalities
• Malnutrition
• Medications
• Smoking
8. Mechanical etiologies:-
• Malreduction
• Malposition
• Malalignment
• Distraction
• Inappropriate Stabilization
• Too little or insufficient fixation
• Too much or rigid fixation
• Inappropriate implant choice
• Inappropriate implant position
• Technical error(s)
9. Most common sites:-
• Neck of femur
• Scaphoid
• Lower third tibia
• Lower third ulna
• Lateral condyle humerus
