Non-Union Tibial Fracture

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