The effect of hallux abducto valgus surgery on the sesamoid apparatus position

A new parameter, the tibial sesamoid-second metatarsal distance, was establ ished to determine whether the sesamoids move in relation to the foot in ha llux abduct valgus surgery. The reliability of the tibial sesamoid-second m etatarsal distance was assessed and shown to be excellent. Seventy-five fee t underwent surgical correction of hallux abducto valgus. Four radiographic parameters - the intermetatarsal angle, the hallux abductus angle, the tib ial sesamoid position, and the tibial sesamoid-second metatarsal distance - were measured before and after surgery. The hallux abductus angle, interme tatarsal angle, and tibial sesamoid position were all significantly reduced following surgery. The tibial sesamoid-second metatarsal distance was not affected by hallux abducto valgus correction. Thus the correction in sesamo id position gained with hallux abducto valgus correction is a direct result of lateral translocation of the metatarsal head, with no contribution from change in position of the sesamoid apparatus relative to the foot.