Calcaneonavicular coalition

Last revised by Dr Mohamed Saber ◉ on 11 Feb 2021

Citation, DOI & article data

Citation:

Stanislavsky, A., Saber, M. Calcaneonavicular coalition. Reference article, Radiopaedia.org. (accessed on 26 Jun 2022) https://doi.org/10.53347/rID-14217

DOI:

https://doi.org/10.53347/rID-14217

Permalink:

https://radiopaedia.org/articles/14217

rID:

14217

Article created:

07 Jul 2011 by Dr Alexandra Stanislavsky ◉

Revisions:

25 times by 11 users - see full revision history

System:

Musculoskeletal

Section:

Anatomy

Tag:

foot

Synonyms:

Calcaneo-navicular coalition

Calcaneonavicular coalition is one of the two most common subtypes of the tarsal coalition, the other being talocalcaneal coalition. As with any coalition it may be osseous (synostosis), cartilaginous (synchondrosis) or fibrous (syndesmosis).

Radiographic features

This type of coalition is more easily diagnosed on plain film than talocalcaneal coalition.

Plain radiograph

Oblique view

best at depicting calcaneonavicular coalition directly as a calcaneonavicular bar

AP view

may also directly show the coalition
indirect signs include
- the broad proximal surface of navicular: broader than the articulating talar head
- lateral tapering of navicular

Lateral view

Indirect signs include:

anteater sign: an elongated anterior process of the calcaneus
reverse anteater sign: elongated lateral navicular
talar beak
short talar neck

CT

CT can be used to confirm the diagnosis where this was equivocal or not seen on plain films. It may also be used for surgical planning.

MRI

MRI is probably more helpful in assessing and characterizing cartilaginous and fibrous coalition and allows assessment of associated bone and soft tissue edema.

Treatment and prognosis

As with any tarsal coalition, non-operative management may allow some improvement in symptoms initially, but they usually return. Usually, surgical treatment with excision of the coalition is required.