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Inferior articular surface of tibia

The inferior articular surface of the tibia, also known as the tibial plafond, is the distal weight-bearing surface of the tibia that forms the superior part of the ankle (talocrural) joint. It articulates with the trochlea of the talus and plays a central role in load transmission and joint congruity during standing and gait.

It is a critical anatomical region in orthopedic anatomy, trauma assessment, and imaging of the ankle joint.

Synonyms

  • Tibial plafond

  • Distal tibial articular surface

Location

  • Situated at the distal end of the tibia

  • Forms the roof of the ankle (talocrural) joint

  • Articulates inferiorly with the trochlea of the talus

  • Medially continuous with the medial malleolus articular surface

  • Laterally related to the fibular incisura (tibiofibular syndesmosis)

Anatomical components

  • Central articular surface:

    • Slightly concave, covered by hyaline cartilage

  • Medial extension:

    • Contributes to the medial malleolar articular surface

  • Anterior margin:

    • Broad and relatively flat

  • Posterior margin:

    • Narrower, forming the posterior tibial lip

  • Subchondral bone plate:

    • Supports the articular cartilage

Relations

Inferiorly:

  • Trochlea of the talus

Medially:

  • Medial malleolus

  • Deltoid ligament complex

Laterally:

  • Fibular notch (incisura fibularis)

  • Distal tibiofibular syndesmosis

Anteriorly:

  • Anterior joint capsule

  • Anterior talofibular ligament region

Posteriorly:

  • Posterior joint capsule

  • Posterior talofibular ligament region

X-ray appearance

Ankle radiographs (AP, mortise, lateral views):

  • Inferior articular surface: Smooth, dense horizontal line forming the tibial plafond

  • Joint space: Uniform spacing with the talar dome

  • Margins: Sharp cortical outline

  • Alignment: Parallel to the superior talar surface

CT appearance (Pre-contrast)

Non-contrast CT:

  • Articular surface: Well-defined cortical and subchondral bone plate

  • Contour: Slightly concave and smooth

  • Trabecular bone: Normal cancellous pattern beneath subchondral plate

  • Joint congruity: Precise delineation of tibio-talar articulation

  • Syndesmotic relation: Clear visualization of fibular notch

MRI appearance

T1-weighted images:

  • Subchondral bone: High signal marrow beneath low-signal cortical plate

  • Articular cartilage: Low-to-intermediate signal thin layer

  • Joint space: Low signal unless fluid is present

T2-weighted images:

  • Articular cartilage: Intermediate signal

  • Joint fluid: High signal outlining the plafond

  • Cortical bone: Low signal

STIR:

  • Bone marrow: Uniform fat suppression

  • Subchondral region: Clearly delineated beneath cartilage

  • Joint fluid: Bright signal

Proton density fat-saturated (PD FS):

  • Cartilage: Intermediate signal against suppressed marrow

  • Joint fluid: Bright high signal

  • Subchondral bone: Well visualized due to fat suppression

  • Ligament insertions: Clearly defined adjacent to the articular surface

CT VRT 3D image

Inferior articular surface of the tibia

MRI image

Inferior articular surface of the tibia mri anatomy labelled image-img-00000-00000

CT image

Inferior articular surface of the tibia ct coronal