Non-Union
Tibial Fractures

General Considerations 

  • Delayed union is the term applied when a fracture has not healed within the period of time that would be considered adequate for bone healing for that particular sites
    • Holds out the promise that union will eventually occur without further intervention
    • For tibial fractures, healing should occur in 16 weeks
  • Non-union is the term applied to a fracture that will not unite without additional intervention
    • Usually by 6-9 months for tibial fractures
  • Non-union of tibia is fairly common
    • Estimated to range from 2-10% of all tibial fractures 

Associations

  • Most closely associated with the type of tibial fracture
  • Open or compound fracture
  • Degree of comminution
  • Less soft tissue covers fracture
  • High energy fractures (automobile and motorcycle accidents)
  • Cigarette smoking places patient at higher risk
  • Use of nonsteroidal anti-inflammatory medications may inhibit bone healing 

Types

  • Hypertrophic nonunions
    • Exuberant callus formation
    • Because of their vascularity, they have excellent healing potential
    • Result from inadequate immobilization of the fracture
  • Atrophic (oligotrophic) nonunions
    • Absence of callus and bone ends that may be tapered and osteopenic or sclerotic
    • Because of their lack of vascularity, they have poor healing potential
    • A subcategory of this type may be freely movable and form a pseudarthrosis
  • Normotrophic nonunions
    • Share characteristics of both of the above 

Imaging Findings

  • Conventional radiographs are the study of first choice
    • In established non-union, the ends of the fracture fragments are sclerotic and typically smooth
    • Bones are joined by fibrous tissue
  • CT may be helpful in establishing presence of bony bridging
  • MRI is most sensitive for osteomyelitis

Differential Diagnosis

  • Congenital pseudarthrosis of the tibia
    • Occurs in children
    • Associated with neurofibromatosis and fibrous dysplasia

Treatment

  • Hypertrophic nonunions are treated with rigid stabilization
  • Atrophic nonunions require augmentation
    • May be in the form of bone grafting or biologic stimulation

Complications

  • Infection of a previously aseptic non-union
  • Malalignment
  • Shortening
  • Continued non-union

 

Tibial non-union. Frontal radiograph of the distal tibia shows a smooth and sclerotic line at the fracture ends (blue arrows) in a patient 14 months after the original fracture, signs of non-union. There is some external callus formation present (white arrow). There is also non-union of an associated fibular fracture.
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eMedicine Minoo Patel, MBBS, MS, FRACS, James McCarthy, MD, John Herzenberg, MD, FRCSC

Wheeless’ online textbook of Orthopedics