Fracture Healing Outcomes: Union, Delayed Union, Non Union, Malunion and Refracturing

Outcomes of fracture healing include:

Union

Fracture healing takes twice as long as the expected time for a specific location
Physical examination: the fracture site has local swelling and movement or partial weight bearing is painful

in this fracture healing outcome, the Bone fails to unite
Fracture healing doesn’t occur in less than 9 months since initial injury and no signs of healing in the final three months
Causes of non union
- Mechanical instability
- Impaired vascularity
- Infection
Common sites: scaphoid bone, femoral neck, tibial shaft
History of pain
Examination: tenderness over the fracture site
X ray: persistent fracture line seen

Hypertrophic: abundant callus formation but there is radiolucent line at the non union line on x ray
Oligotrophic: little or no callus formation, radiolucent line on x ray too
Atrophic: no callus formation, osteopenia, sclerotic avascular bone segments
Infected: osteopenia, sclerotic avascular bone segments, segmental bone loss, clinical signs of infection
Synovial pseudoarthrosis (false joint) also could be (hypertrophic, oligotrophic, atrophic, infected)

Healing in non anatomical position
Partially compensated for by the remodeling of the bone
May lead to functional impairment or poor aesthetic
Causes:
- Inaccurate reduction
- Inadequate immobilization
Complications: osteoarthritis if there is intra articular malunion or joint instability

Fixation materials should be removed within 18 months after fracture healing
If left in place for longer than that leads to cortical atrophy and high risk of refracturing

This article is apart from Orthopedic Trauma Basic Principles Course, This course covers these topics: