Congenital absence of the tibial sesamoid: a report of two cases.

Congenital absence of the tibial sesamoid is a rare condition that has been infrequently reported in the podiatric literature. Two cases of congenital absence of the tibial sesamoid are presented with an associated hallux abducto valgus deformity. The role of a weakened medial flexor hallucis brevis tendon as a predisposing factor leading to a hallux abducto valgus deformity is discussed.