Kager's triangle

Kager's triangle is a sharply marginated radiolucent triangle seen posteriorly on lateral radiographs of the ankle. It represents the Kager fat pad.

It is bordered anteriorly by the flexor hallucis longus (FHL) muscle and tendon, posteriorly by the Achilles tendon, and inferiorly by the calcaneus. The anteroinferior corner of the triangle is related to the posterior ankle joint, while posterolaterally it is related to the retrocalcaneal bursa

The alteration of it's radiographic appearance in the form of obliteration or distortion of its borders are subtle indicators of pathology involving the posterior ankle. 

Share article

Article information

rID: 1544
Tag: stub, cases
Synonyms or Alternate Spellings:
  • Kager triangle

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: in black (also has a non-ossifying fibroma)
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

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

    Alert accept Thank you for updating your details.