Factors predisposing to delayed union
Severe soft tissue damage.
Inadequate blood supply.
Infection.
Insufficient splintage.
Excessive traction.
Older age.
Severe anaemia.
Diabetes.
Low vitamin D level.
Hypothyroidism.
Medications including NSAIDs and steroids.
Infection.
Complicated/compound fracture.
Osteoporosis.