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Superior facet of talus

The superior facet of the talus, also known as the trochlear surface of the talus, is the smooth, dome-shaped articular surface forming the superior part of the talar body. It articulates with the distal tibia and fibula to form the ankle (tibiotalar) joint and plays a central role in ankle motion and load transmission.

It is a key anatomical and imaging landmark in ankle evaluation, trauma, sports injuries, and degenerative joint assessment.

Synonyms

  • Trochlea of the talus

  • Talar dome

Location

  • Situated on the superior surface of the talar body

  • Between the medial and lateral malleoli

  • Inferior to the tibial plafond

  • Forms the inferior articular surface of the ankle joint

  • Oriented horizontally with a slight anterior widening

Anatomical components

  • Hyaline cartilage–covered articular surface

  • Medial and lateral margins:

    • Articulate with the malleolar facets

  • Anterior portion:

    • Slightly wider than the posterior portion

  • Subchondral bone plate beneath cartilage

Relations

Superiorly:

  • Tibial plafond

  • Fibular articular surface

Inferiorly:

  • Body of the talus

Medially:

  • Medial malleolus and deltoid ligament complex

Laterally:

  • Lateral malleolus and lateral collateral ligaments

Anteriorly:

  • Anterior ankle joint capsule

Posteriorly:

  • Posterior ankle joint capsule and posterior talar process

X-ray appearance

Plain radiographs (AP, mortise, and lateral ankle views):

  • Superior facet: Appears as a smooth, curved radiopaque contour of the talar dome

  • Joint space: Uniform tibiotalar joint space overlying the facet

  • Best visualized on: Mortise and lateral views

CT appearance

Non-contrast CT:

  • Articular surface: Well-defined convex bony contour

  • Subchondral bone: Uniform density beneath the cartilage

  • Joint congruity: Clearly depicted with tibial plafond and malleoli

  • Excellent for assessing surface contour and alignment

MRI appearance

T1-weighted images:

  • Subchondral bone: High signal intensity

  • Cortical bone plate: Low signal

  • Cartilage: Intermediate-to-low signal thin layer over the talar dome

T2-weighted images:

  • Articular cartilage: Intermediate signal with smooth surface

  • Joint fluid: High signal outlining the facet

  • Subchondral bone: Low-to-intermediate signal

STIR:

  • Fat suppression: Uniform suppression of marrow fat

  • Articular surface: Clearly outlined by surrounding fluid

  • Excellent contrast between cartilage, bone, and joint space

Proton density fat-saturated (PD FS):

  • Cartilage: Well-demonstrated with smooth margins

  • Joint fluid: High signal

  • Subchondral bone: Suppressed marrow fat with clear cortical outline

CT VRT 3D image

Superior facet of talus

MRI image

Superior facet of talus mri anatomy labelled image-img-00000-00000

MRI image

Superior facet of talus mri anatomy labelled image-img-00000-00000_00001