Os trigonum

X-ray of the
right foot by lateral projection, with shapes representing where common accessory and sesamoid bones would be, colored by their prevalences, and with representative shapes.
Wikipedia • CC0
Symptomatic
non-united fracture of the entire posterior process of the talus. Schematic diagram of pathologies involving the lateral tubercle of the posterior talar process (FHL marked by the orange circle).
www.eurorad.org • CC by-nc-sa-4.0
Posterior
ankle impingement syndrome • Posterior ankle impingement (Os trigonum syndrome) - Ganzer Fall bei Radiopaedia
Saber M, Posterior ankle impingement (Os trigonum syndrome). Case study, Radiopaedia.org (Accessed on 05 Jan 2023) https://doi.org/10.53347/rID-88440 • CC by-nc-sa 3.0 (modified)
Posterior
ankle impingement syndrome • Posterior ankle impingement (os trigonum) syndrome - Ganzer Fall bei Radiopaedia
Abougazia A, Posterior ankle impingement (os trigonum) syndrome. Case study, Radiopaedia.org (Accessed on 05 Jan 2023) https://doi.org/10.53347/rID-22745 • CC by-nc-sa 3.0 (modified)
Os trigonum
im Röntgenbild
Wikipedia • CC BY-SA 3.0
Ankle
impingement. A T2-weighted MRI with reactive edema surrounding an os trigonum
josr-online.biomedcentral.com • CC-by-4.0
Ankle
impingement. A lateral radiograph demonstrates a large os trigonum
josr-online.biomedcentral.com • CC-by-4.0
Ungewöhnlich
großes Os trigonum
Wikipedia • CC BY-SA 4.0
Großes,
unregelmäßiges Os trigonum und Os talonaviculare.
Wikipedia • CC BY-SA 3.0
Knochenkern
dorsal am Talus bei einem 10-Jährigen in der Position eines Os trigonums.
Wikipedia • CC BY-SA 3.0
nicht verwechseln mit: Os triangulare
Radiopaedia • CC-by-nc-sa 3.0 • de

The os trigonum (plural: ossa trigona) is one of the ossicles of the foot and can be mistaken for a fracture.

It sits posterior to the talus on the lateral foot radiograph and represents a failure of fusion of the lateral tubercle of the posterior process. It is estimated to be present in ~7% of adults . Bilateral os trigona are seen in 2% of individuals . The ossicle usually forms between 7-13 years of age and fuses with the talus in a majority of patients by approximately age 17 , otherwise persisting as an os trigonum.

Related pathology

Differential diagnosis

General imaging differential considerations include:

See Also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Os trigonum:
akzessorische
Knochen Fuß
Wikipedia • CC0
Processus
posterior tali Fraktur
www.eurorad.org • CC by-nc-sa-4.0
posteriores
Impingement am Sprunggelenk
bmcmusculoskeletdisord.biomedcentral.com • CC-by-4.0