The apophysis is a normal secondary ossification center that is located in the non-weight-bearing part of the bone and eventually fuses with it over time (most of the apophyses fuse during the 2nd decade of life, but this process can be delayed, especially in female athletes). The apophysis is a site of tendon or ligament attachment, as compared to the epiphysis which contributes to a joint, and for that reason, it is also called 'traction epiphysis'.

When unfused, apophyses can easily be mistaken for fractures.

In skeletally immature patients the physeal cartilage is weaker than adjacent bone, ligaments and tendons. therefore, it is most prone to injury in this age group. Apophyseal injury can occur in the setting of acute trauma, which often leads to apophyseal avulsion, or in chronic overuse, which is associated with apophyseal stress injury.

Given the similar development with epiphyses, primary bone lesions that are typically located in the epiphyses can also occur in apophyses.

Related pathology

See also

Terms used in radiology

Article information

rID: 25808
Section: Anatomy
Tag: refs, stub, stub, refs
Synonyms or Alternate Spellings:
  • Traction epiphysis
  • Apophyses

Support Radiopaedia and see fewer ads

Cases and figures

  • Figure 1
    Drag here to reorder.
  • Figure 2
    Drag here to reorder.
  • Figure 3: physeal anatomy
    Drag here to reorder.
  • Case 1: apophysis and fracture
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.