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Apex of medial malleolus

The apex of the medial malleolus refers to the most inferior and distal tip of the medial malleolus of the tibia. It forms a prominent bony landmark on the medial aspect of the ankle and plays an important role in ankle stability by providing attachment for ligamentous structures and contributing to the medial ankle mortise.

It is a key reference point in orthopedic anatomy, trauma assessment, ankle imaging, and surgical planning.

Synonyms

  • Tip of the medial malleolus

  • Distal pole of the medial malleolus

Location

  • Situated at the distal end of the tibia

  • Forms the medial projection of the ankle joint

  • Inferior to the tibial plafond

  • Medial to the talar dome

  • Superficial and subcutaneous on the medial ankle

Anatomical components

  • Osseous projection of the tibia

  • Cortical shell with underlying cancellous bone

  • Ligament attachment zone:

    • Superficial and deep fibers of the deltoid ligament

  • Articular relationship:

    • Contributes to the medial wall of the ankle mortise

Relations

Anteriorly:

  • Anterior tibiotalar joint capsule

Posteriorly:

  • Posterior tibiotalar ligaments

  • Posterior tibial tendon (in close proximity)

Medially:

  • Subcutaneous tissue and skin

Laterally:

  • Talar medial articular surface

Inferiorly:

  • Medial surface of the talus

Superiorly:

  • Tibial plafond and distal tibial metaphysis

X-ray appearance

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

  • Apex: Seen as the pointed distal tip of the medial malleolus

  • Cortical outline: Sharp and well-defined

  • Relationship: Forms the medial boundary of the ankle mortise

  • Best seen on: Mortise and AP views

CT appearance 

Non-contrast CT:

  • Apex: Well-defined bony prominence at the distal tibia

  • Cortical margins: Smooth and sharply outlined

  • Trabecular pattern: Normal cancellous bone

  • Spatial assessment: Excellent for evaluating contour, orientation, and small cortical irregularities

  • Relationship to talus: Clearly demonstrated

MRI appearance

T1-weighted images:

  • Cortical bone: Low signal intensity

  • Marrow of medial malleolus: High signal intensity

  • Apex contour: Clearly delineated against surrounding soft tissues

T2-weighted images:

  • Cortex: Low signal

  • Adjacent joint fluid: High signal outlining the apex

  • Surrounding ligaments: Low-to-intermediate signal

STIR:

  • Fat suppression: Uniform suppression of marrow fat

  • Apex margins: Well visualized

  • Joint and tendon sheaths: Bright signal

Proton density fat-saturated (PD FS):

  • Bone marrow: Suppressed fat signal

  • Joint fluid: High signal

  • Deltoid ligament fibers: Well seen as low-signal bands attaching near the apex

CT VRT 3D image

Apex of medial malleolus 3d

MRI image

Apex of medial malleolus mri anatomy labelled image-img-00000-00000

CT image

Apex of medial malleolus ct