Non-neoplastic or metabolic disease

Author: Dariusz Borys, M.D. (see Authors page)

Revised: 3 October 2016, last major update June 2012

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Bone Fracture[title]

Related topics: Stress fractures, Subchondral insufficiency fractures
Cite this page: Fracture. website. Accessed October 19th, 2018.
Definition / general
  • Break in continuity of bone, often with severance of blood vessels, periosteum or muscle
  • Complete (bone broken completely) vs. incomplete
  • Closed (intact overlying tissue, also called simple) vs. compound (fracture site communicates with skin surface)
  • Displaced (ends of bone not aligned)
  • Comminuted (many fragments)
  • Pathologic (due to diseased bone) or traumatic
  • Fractures often due to weakened bone (osteoporosis, tumor, infection) or falls in elderly and children

Types of fractures:
  • Spiral configuration through cortex is typical
  • Transverse fractures (like breaking chalk) are associated with Paget’s disease, osteopetrosis or other severe bone disturbances
  • Stress or insufficiency fractures - see below
  • Avulsion fractures are associated with trauma at ligamentous and tendinous insertions, often in pelvis or distal thigh

Osgood-Schlatter’s disease:
  • Avulsion fractures of tibial tubercle causing fragmentation, in children
  • Most common causes of knee pain in adolescents, pain in children and young athletes usually between the ages of 10 and 15
  • Occurs due to rapid bone growth plus high level of sporting activity; associated with overuse injury
  • Can be quite painful, but usually resolves itself within 12 to 24 months ( Schlatter Disease)

Primary callus:
  • Exuberant cartilage and disorderly membranous bone may resemble osteosarcoma
  • Increased callus is present in unstable areas

  • False joint developing after chronic nonunion of a fracture

Congenital Pseudoarthrosis:
Healing process:
  • Hematoma forms between two ends of bone, creates fibrin mesh which seals fracture site
  • Young capillaries enter hematoma
  • Dead bone reabsorption begins at 3 days
  • Periosteal inner layer promotes intramembranous bone growth on each side of fracture, which meets at fracture site to form a primary callus, which anchors ends but doesn’t support weight bearing
  • This is resorbed and replaced by secondary callus, composed of mature lamellar bone
  • New bone is laid down along lines of stress
  • In children, marked bone remodeling occurs, even with gross deformities or shortening of a long bone
  • Open reduction and internal fixation of fractures is usually not needed
  • Movement along fracture line creates lining of synovial cells and pseudoarthritis
  • Soft tissue must be removed and bone stabilized to promote healing
  • Fractures may not heal due to improper immobilization, devascularization of bone fragments, persistent infection or interposition of soft tissue between ends of bone
  • Noncorrosive nails are isolated from bone substance by fibrous tissue; do not elicit foreign body giant cell reaction

Case reports
Microscopic (histologic) description
  • Varies with type of injury
  • A few days - acute tissue damage and hemorrhage, necrotic bone [empty lacunae, poorly staining bone matrix] at fracture, may be more extensive in patella, femoral neck, carpal scaphoid
  • 1 - 2 weeks - hypercellular, hypervascular tissue, often with brisk mitotic activity, resembles sarcoma but without atypia or atypical mitotic figures; reduced callus in midshaft of tibia or other poorly vascularized areas
  • Callus reduced if rigid internal or external surgical fixation
Microscopic (histologic) images

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Remodeling in metaphysis