Abnormal morphology of the proximal phalanx of the hallux

What it means

An abnormal shape or form of the proximal phalanx of the big toe.

In contrast to the proximal phalanges of the digits 2-5, the proximal phalanx of the big toe is embryologically equivalent to the middle phalanges of the other digits, whereas the first metatarsal is embryologically of phalangeal origin and as such equivalent to the proximal phalanges of the other digits.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Abnormality of the proximal phalanx of the hallux