Subtalar coalition: diagnosis with the C sign on lateral radiographs of the ankle

L M Lateur, L R Van Hoe, K V Van Ghillewe, S S Gryspeerdt, A L Baert, G E Dereymaeker
Radiology 1994, 193 (3): 847-51

PURPOSE: To evaluate the usefulness of the C sign, a C-shaped line formed by the medial outline of the talar dome and the inferior outline of the sustentaculum tali, in the diagnosis of subtalar coalition (SC) on lateral radiographs of the ankle.

MATERIALS AND METHODS: Lateral ankle radiographs obtained before and after the availability of computed tomography (CT) at the authors' institution were retrospectively and prospectively evaluated for the presence of the C sign. SC was confirmed with surgery for the retrospective study and with CT or magnetic resonance (MR) imaging for the prospective study.

RESULTS: The C sign was seen on lateral radiographs in all 18 cases of SC in the retrospective study. Fifteen cases of SC were found in the prospective study, 13 of which had a C sign on lateral radiographs. Two additional findings on the CT or MR images were consistently associated with SC and caused the C sign on the lateral radiographs: a horizontal inferior surface of the sustentaculum tali and pathologic calcaneal valgus in the coronal plane.

CONCLUSION: The C sign proved to be the most reliable indicator of SC on the lateral radiograph of the ankle.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"

We want to hear from doctors like you!

Take a second to answer a survey question.