Definition of sesamoid in English:


(also sesamoid bone)


  • A small independent bone or bony nodule developed in a tendon where it passes over an angular structure, typically in the hands and feet. The kneecap is a particularly large sesamoid bone.

    • ‘The patella is the largest sesamoid bone in the body and provides increased mechanical advantage for knee extension.’
    • ‘Plain radiographs may reveal the type of injury by the position of the sesamoids.’
    • ‘Another characteristic of muscles subjected to high force regimes is the presence of sesamoids or calcified central tendons.’
    • ‘Hunt discovered a high fracture that does not involve the sesamoid bones.’
    • ‘A sesamoid bone may develop in the bicipital tendon over the radial tuberosity.’


Late 17th century: from sesame (with reference to the similarity in shape of a sesame seed) + -oid.