Biphalangeal fifth toe.
BACKGROUND: A biphalangeal fifth toe is a common variant in the European population. The frequency is higher in the Japanese population. It is considered an anatomical variant of the normal triphalangeal fifth toe. METHODS: Patients divided into three study groups were retrospectively reviewed to determine the effect of a biphalangeal fifth toe on the occurrence of clinically symptomatic pathology of the fifth ray. RESULTS: The prevalence of a biphalangeal fifth toe in patients with hammer or claw toes was 65%, bunionettes 47%, and overriding fifth toe 37%. Only for the group with hammer or claw toes was prevalence significantly higher than that in the control group (39%). CONCLUSION: The stiffness and rigidity of the biphalangeal fifth toe may predispose it for symptomatic hammer or claw toe.