fibular sesamoid of metatarsal head ( RID2990 ) History is important, as this patient has an asymptomatic 3rd IS neuroma. 1st IS neuroma is rare (up to 2.5% in large series). Here there is HAV with smooth remodeling of the crista of the 1st MT head and marked lateral subluxation (nearly dislocation) of the sesamoids, with the fibular sesamoid situated in the plantar 1st interspace. I suspect it may be compressing the digital nerve in this location. Ive searched but cannot find this reported.