Hallux sesamoid

Dr Aditya Shetty and Dr Henry Knipe et al.

The hallux sesamoid bones are paired, dual 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 flexor hallucis brevis muscle respectively 1. They are usually 1.3cm long x 0.3cm wide 2

Along with the tendons/ligaments listed in Attachments below form the hallux sesamoid complex

Articulations
  • cartilaginous dorsal surface articulates with the grooved undersurface of the first metatarsal head
Attachments
  • intersesamoid ligament - connects the two hallux sesamoids strongly to form on 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
Ossification
  • occurs between 8-10 years of age 1

Lower limb anatomy
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Article Information

rID: 26894
Section: Anatomy
Tags: foot, ossicle
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

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    Case 1: bipartite lateral and normal medial
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