[Sesamoid pathology of the 1st metatarsal bone]

The sesamoid region constitutes an "anatomo-clinical entity" because the small sesamoid bones and the tendino-sero-cutaneous formations which surround them are in close association. Subjected to various microtraumatisms, (professional, sports or static), it expresses its pathology through a painful sesamoid point, a localized tumefaction that is more or less ifnlammatory (sometimes with a pseudo-gout aspect) or a painful corn that disturbs walking. The observation of radiologic alterations of the sesamoid bones results in the discussion of osteonecrosis (Renander's disease) or a fracture. This region may also be the site of a specific micro-cristalline inflammation (with deposit of various crystals) or a rheumatic (mainly rheumatoid, sometimes psioriatic or spondylarthritic) responsible for sesamoid alterations of variable intensity. I can also be involved in an infectious process that is either acute or chronic (fistulization). The sesamoid region has a rich pathology, that is often poorly understood since it is inadequately investigated.