Problems With Fracture Union

Signs of healing and non-union

Symptoms and signs of fracture healing

  • Resolution of pain and function
  • Abscence of point tederness
  • No local oedema
  • Resolution of movement at fracture site

Symptoms and signs of non-union

  • Ongoing pain
  • Ongoing oedema
  • Movement at the fracture site

Investigations

  • Bridging callus may be seen on x-ray
  • CT scans can confirm or exclude bridging callus where their is doubt on bony union

Delayed union

  • Different fractures heal at different rates, and healing is dependent on the energy of the injurty as well as the age and overall health of the patient
  • The tibia is one of the slowest healing bones - fractures typically take around 16 weeks to heal and can take over a year to unit
  • Femoral shaft also typically take 3-4 months to heal
  • Metaphyseal fractures tend to heal more quickly than cortical fractures
  • A delayed union is a fracture that is not healed within the expected time
  • Infection can result in a delayed union
    • If infection is diagnosed, healing can occur if the infection is suppressed with antibiotics however the fracture may go on to an infected non-union

Non-union

  • Hypertrophic non-union can occur due to instabiity and excessive motion at the fracture site
  • Atrophic non-union can occur due to rigid fixation with a fracture gap, lack of blood supply to the fracture site, chronic disease or soft tissue interposition
  • Infection can also lead to atrophic or hypertrophic non-union
  • Some fractures are particularly prone to problems with healing due to poor blood supply:
    • Scaphoid waist fractures
    • Fractures of the distal clavicle
    • Subtrochanteric fractures of the femur
    • Jone's fracture of the fifth metatarsal
  • Some intra-articular fractures may not unite due to synovial fluid inhibiting healing if a fracture gap exists (intracapsular hip fracture, scaphoid fracture)

Malunion

  • Fracture has healed in a non-anatomic position sufficient to cause pain, stiffness, loss of function and deformity