Rare diseases · Sign or symptom

Triangular shaped thumb phalanx

Triangular shaped thumb bone

HP:0009657

What it means

Abnormal shape of one or more phalanges of the thumb such that affected phalanges resemble a triangle.

A triangular or so called delta shaped phalanx is a typical result after a bracket epiphysis of the affected phalanx (in this case metacarpal, see explanation above).

Part of the broader category

Abnormality of thumb phalanx

Also called: Triangular shaped phalanges of the thumb · Triangular thumb phalanges

Triangular shaped thumb phalanx

Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.

Start free with Eleplan

This page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.