Hallux sesamoid

The hallux sesamoid bones are paired ossicles of the foot. They function as a fulcrum to increase the leverage of both flexor hallucis brevis and longus

The hallux sesamoids are ovoid-shaped ossicles. There is a medial (tibial) and lateral (fibular) hallux sesamoid and are embedded within the substance of the medial and lateral slips of the tendon of the flexor hallucis brevis muscle respectively 1. They are usually 1.3 cm long x 0.3 cm wide 2.

Along with the tendons/ligaments listed below, the sesamoid bones form the hallux sesamoid complex.

  • cartilaginous dorsal surface articulates with the grooved undersurface of the first metatarsal head
  • intersesamoid ligament: connects the two hallux sesamoids strongly to form one functional unit 2
  • medial and lateral collateral ligaments
  • abductor hallucis tendon: medial aspect of hallux sesamoid complex
  • adductor hallucis tendon: lateral aspect of hallux sesamoid complex
  • occurs between 8-10 years of age 1
Anatomy: Lower limb
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Article information

rID: 26894
Section: Anatomy
Synonyms or Alternate Spellings:
  • Hallux sesamoid bone
  • Hallux sesamoid bones
  • Hallux sesamoids
  • First metatarsal sesamoid
  • Sesamoid of flexor hallucis brevis

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Cases and figures

  • Case 1: bipartite lateral and normal medial
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  • Case 2: hallucal and lesser metatarsal sesamoids
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