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Plantar cuneocuboid ligament

The plantar cuneocuboid ligament is a strong fibrous band located on the plantar aspect of the foot, connecting the cuboid bone to the lateral (third) cuneiform. It forms part of the plantar ligamentous complex that stabilizes the tarsal joints and maintains the lateral longitudinal arch of the foot.

It is one of the key stabilizers of the calcaneocuboid–cuneiform region, contributing to both midfoot rigidity and load-bearing efficiency during gait. The ligament resists excessive dorsiflexion and separation of the cuboid and cuneiform bones.

Synonyms

  • Short plantar cuneocuboid ligament

  • Inferior cuneocuboid ligament

  • Plantar ligament of cuneocuboid joint

Attachments

  • Proximal (medial) attachment: Plantar surface of the lateral cuneiform bone

  • Distal (lateral) attachment: Plantar aspect of the cuboid bone, near its ridge and groove for the peroneus longus tendon

Relations

  • Superficial: Long plantar ligament and plantar fascia

  • Deep: Joint capsule of the cuneocuboid joint

  • Medial: Interosseous cuneocuboid ligament

  • Lateral: Peroneus longus tendon as it crosses the cuboid groove

  • Inferior: Fat pad and skin of the plantar surface

Function

  • Stabilization: Reinforces the plantar aspect of the cuneocuboid joint

  • Arch support: Contributes to maintaining the lateral longitudinal arch of the foot

  • Force transmission: Assists in distributing loads from the hindfoot to the forefoot during gait

  • Restriction of movement: Prevents excessive separation or rotation between the cuboid and lateral cuneiform bones

  • Synergistic action: Works with the long plantar and plantar calcaneocuboid ligaments for midfoot integrity

Arterial Supply

  • Branches of the lateral plantar artery (from the posterior tibial artery)

  • Additional small contributions from the dorsalis pedis via perforating branches

Clinical Significance

  • Injury: Sprain or partial tear due to inversion or twisting injuries of the midfoot

  • Degeneration: Common in chronic flatfoot deformity or lateral column overload

  • Associated pathologies: May occur with peroneus longus tendinopathy or cuboid subluxation

  • Symptoms: Localized plantar-lateral midfoot pain, tenderness over cuboid, and difficulty in push-off during gait

  • Imaging relevance: MRI is the preferred modality for evaluating integrity, thickening, or partial tears of the ligament

MRI Appearance

  • T1-weighted images:

    • Normal ligament: low signal intensity (dark) linear band between the cuboid and lateral cuneiform

    • Adjacent muscle and fat: intermediate and bright, providing clear contrast

    • Partial tear: poorly defined fibers with focal intermediate signal and mild thickening

  • T2-weighted images:

    • Normal ligament: dark (low signal)

    • Tears or inflammation: bright hyperintense signal along or within the ligament fibers

    • Surrounding edema or fluid in the plantar soft tissues appears hyperintense, aiding detection

  • STIR:

    • Normal ligament: dark

    • Pathology: bright hyperintense areas due to edema or sprain

    • Excellent for identifying acute injury, inflammation, or plantar soft-tissue edema

  • Proton Density Fat-Saturated (PD FS):

    • Normal: uniformly dark, continuous structure

    • Partial tear: linear or irregular bright signal within or adjacent to ligament

    • Complete tear: discontinuity with fluid-bright gap between attachments

  • T1 Fat-Sat Post-Contrast:

    • Normal ligament: minimal or no enhancement

    • Inflammatory or reactive changes: mild linear enhancement

    • Chronic degeneration: irregular, heterogeneous enhancement due to fibrotic remodeling

CT Appearance

Non-Contrast CT:

  • Ligament appears as a thin soft-tissue density band between cuboid and lateral cuneiform

  • Better appreciated with thin-slice high-resolution CT

  • Indirect signs of injury: joint irregularity, subtle widening, or cortical changes at attachment sites

  • Chronic degeneration may show enthesophytes or calcification

Post-Contrast CT (standard):

  • Ligament not directly enhanced

  • Inflamed surrounding soft tissues or periligamentous edema may show mild enhancement

  • Helpful for detecting osseous avulsion or subchondral reaction at ligament insertions

MRI image

plantar cuneocuboid ligament axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI image

plantar cuneocuboid ligament coronal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000