Outcomes of fracture healing include:

Union

Complete healing of the fracture

• Physical examination: Fracture site is painless on palpation and weight bearing
• X-rays shows bridging callus, the fracture line is replaced by bone

Delayed 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

Non union

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 and Examination

• History of pain
• Examination: tenderness over the fracture site
• X-ray: persistent fracture line seen

Types of non union

• 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)

Non union risk factors

• Old age
• Poor nutrition
• Drugs
• Metabolic disease

Malunion

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

Refracturing

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

Course Topics

This article is a part from the Orthopedics trauma basic principles course, this course also includes these topics:

• Course Introduction
• Bone fracture mechanisms
• Types of bone fractures
• Fracture displacement patterns and fracture description
• Bone healing process
• Fractures healing outcomes
• Trauma management using ATLS
• History taking and examination in orthopedic trauma
• Orthopedic X-ray interpretation basics
• Soft tissue injuries
• Closed fracture treatment
• Gustilo Anderson classification of open fractures
• Open fractures treatment
• Stress fractures
• Pathological fractures
• Growth plate fractures
• Compartment syndrome
• Complication of fractures
• Joint injuries