talocalcaneal coalition

Talokalkaneare
tarsale Koalition beidseits als Zufallsbefund im Rahmen der Diagnostik bei Fibulafraktur mit Beteiligung des hinteren Volkmann-Dreieck. Oben CT, Röntgen und Volumen Rendering rechts; unten CT linkes OSG.
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Lateral X-ray
of a flat foot with C-sign, which is a bony bridge between the talar dome and sustentaculum tali, in combination with a prominent inferior border of the sustentaculum tali. This represents a talocalcaneal coalition, which is an abnormal connection between the talus and calcaneus, and is thought to cause the flat foot deformity.
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A female
dancer with recurrent right foot pain: a case of talocalcaneal coalition. STIR coronal image shows a talocalcaneal bridge with concomitant bone marrow oedema that involves also the opposing surfaces of talus, calcaneus and medial malleolus.
www.eurorad.org • CC by-nc-sa-4.0
A female
dancer with recurrent right foot pain: a case of talocalcaneal coalition. Sagittal proton density-weighted image shows a talocalcaneal bridge (arrow) with continuity of marrow signal intensity.
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Dual
calcaneonavicular and talocalcaneal fibrous coalition. MRI, Sagittal STIR of the left foot at the level of the talocalcaneal joint.
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Dual
calcaneonavicular and talocalcaneal fibrous coalition. MRI, Coronal T1 of the left foot at the level of talocalcaneal joint
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Dual
calcaneonavicular and talocalcaneal fibrous coalition. MRI, Sagittal T1 of the left foot at the level of the talocalcaneal joint.
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Dual
calcaneonavicular and talocalcaneal fibrous coalition. Lateral radiography of the left foot.
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Komplexe
tarsale Koalition mit Verschmelzung von Talus und Kalkaneus, den Metatarsalia 3 und 4 und Symphalangismus Mittel- und Endglied D3 bis D5 (bei D5 fast ein Normalbefund). Zufallsbefund bei einer 36-jährigen.
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A female
dancer with recurrent right foot pain: a case of talocalcaneal coalition. Axial Fast-Field-Echo T2-weighted image shows a talocalcaneal bridge (arrow) that includes the middle facet of subtalar joint.
www.eurorad.org • CC by-nc-sa-4.0
Talokalkaneare
Koalition beidseits: Links knöchern und ausgeprägt, rechts nur als deutlich vergröbertes Sustentaculum tali mit entsprechender Veränderung der korrespondierenden Talusfläche. Oben koronare Computertomografie, unten Röntgen seitlich und sagittale Computertomografie der linken Seite. Bei aktuellem Trauma zeigt sich im Röntgen noch eine Abscherung vorne am Talus.
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A female
dancer with recurrent right foot pain: a case of talocalcaneal coalition. STIR coronal image shows bone marrow oedema of the opposing surfaces of talus, calcaneus and medial malleolus.
www.eurorad.org • CC by-nc-sa-4.0
Komplexe
tarsale Koalition mit Verschmelzung von Talus und Kalkaneus, den Metatarsalia 3 und 4 und Symphalangismus Mittel- und Endglied D3 bis D5 (bei D5 fast ein Normalbefund). Zufallsbefund bei einer 36-jährigen.
Wikipedia • CC BY-SA 3.0
A female
dancer with recurrent right foot pain: a case of talocalcaneal coalition. Axial Fast-Field-Echo T2-weighted image shows a talocalcaneal bridge (arrow) that includes the middle facet of subtalar joint.
www.eurorad.org • CC by-nc-sa-4.0
Komplexe
tarsale Koalition mit Verschmelzung von Talus und Kalkaneus, den Metatarsalia 3 und 4 und Symphalangismus Mittel- und Endglied D3 bis D5 (bei D5 fast ein Normalbefund). Zufallsbefund bei einer 36-jährigen.
Wikipedia • CC BY-SA 3.0
Talocalcaneal
coalition combined with flatfoot in children: diagnosis and treatment: a review. The image of CT shows a bony talocalcaneal coalition.
josr-online.biomedcentral.com • CC-by-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Talocalcaneal coalition is one of the two most common sub-types of tarsal coalition, the other being calcaneonavicular coalition. It accounts for 45% of all tarsal coalitions, and although all three facets of the talocalcaneal joint can be involved, the middle facet is most commonly involved.

Radiographic features

As with any coalition it may be bony, cartilaginous or fibrous. Talocalcaneal coalition often requires cross-sectional imaging for accurate diagnosis.

Plain radiograph

Plain film findings include:

  • C-sign
    • best assessed on a lateral ankle radiograph
    • posterior continuity of the talus and sustentaculum tali
    • sensitivity: 50%
    • specificity: 90%
  • talar beak sign
    • best seen on the lateral ankle radiograph
    • prominent beak at the anterior aspect of the talus

Secondary radiographic features that suggest the diagnosis include close apposition of the middle facet of the talocalcaneal (subtalar) joint or non-visualization of the middle articular facet . Sclerosis around the articular margins of the talocalcaneal joint may also occur.

CT

At CT, coronal reformats are usually the best to appreciate the coalition. Bony coalition is seen as a complete bar of bone between the talus and calcaneus. In non-osseous coalition, there is usually irregularity of the articular surface, narrowing of the joint space and subchondral sclerosis.

MRI 

MRI is more helpful for the assessment of cartilaginous or fibrous coalitions and also demonstrates bone marrow and soft-tissue edema.

Nuclear medicine

On bone scan there is Increased radionucleotide uptake at the site of the coalition may occur due to altered biomechanics at the joint although this is a non-specific finding.

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Talokalkaneare Koalition:
talar beak
sign
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Tarsale
Koalition
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Arthrose
unteres Sprunggelenk
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