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Plantar cuneonavicular ligaments

The plantar cuneonavicular ligaments are a group of strong fibrous bands that connect the plantar surface of the navicular bone to the three cuneiform bones—medial, intermediate, and lateral. They form an essential part of the plantar midfoot complex, contributing to the stability and integrity of the medial longitudinal arch.

These ligaments support the cuneonavicular joint, maintain alignment between the navicular and cuneiform bones, and work synergistically with the plantar calcaneonavicular (spring) ligament and tibialis posterior tendon to provide medial foot support during stance and gait.

They are short but thick, reinforcing the plantar aspect of the cuneonavicular joint capsule and resisting separation during dorsiflexion and weight-bearing.

Synonyms

  • Plantar naviculocuneiform ligaments

  • Plantar cuneonavicular complex

  • Plantar tarsal ligaments

Attachments (Origin and Insertion)

  • Origin: Plantar surface of the navicular bone

  • Insertion: Plantar surfaces of the three cuneiform bones (medial, intermediate, and lateral)

  • Each cuneonavicular articulation has its own distinct plantar ligament band.

Course

  • Short, thick fibrous bands oriented obliquely and medially, blending with the capsule of the cuneonavicular joint.

  • The medial plantar cuneonavicular ligament is the strongest and thickest, often continuous with fibers of the spring ligament and tibialis posterior tendon sheath.

  • The lateral bands are thinner but contribute to lateral stability of the midfoot arch.

Relations

  • Superiorly: Cuneonavicular joint capsule and articular surfaces of navicular and cuneiform bones

  • Inferiorly: Plantar aponeurosis and tendon of tibialis posterior

  • Medially: Spring ligament (plantar calcaneonavicular ligament)

  • Laterally: Plantar cuboideonavicular ligament and peroneus longus tendon

Arterial Supply

  • Medial plantar artery (branch of the posterior tibial artery)

  • Dorsalis pedis artery branches supply the dorsal aspect of the cuneonavicular region

  • Small perforating branches from the tarsal and plantar arterial arches nourish the ligament complex

Function

  • Joint stabilization: Maintains alignment of the cuneonavicular joint

  • Arch support: Strengthens the medial longitudinal arch of the foot

  • Force transmission: Distributes weight-bearing stress across the midfoot

  • Restriction: Prevents excessive dorsiflexion and separation of the cuneonavicular joint during gait

  • Dynamic support: Works with tibialis posterior tendon to stabilize midfoot during propulsion

Clinical Significance

  • Sprains or partial tears: Often occur with midfoot trauma or twisting injuries

  • Degenerative changes: Common in chronic overuse or flatfoot deformities

  • Associated pathologies: Seen with spring ligament complex injuries and posterior tibial tendon dysfunction (PTTD)

  • Symptoms: Medial midfoot pain, tenderness near the navicular–cuneiform junction, and instability during walking

  • Imaging role: MRI is the preferred modality to detect partial tears, degeneration, and associated spring ligament injury

MRI Appearance

  • T1-weighted images:

    • Normal ligament: low signal intensity (dark, thin band) connecting navicular and cuneiform bones

    • Surrounding fat and bone marrow: intermediate-to-high signal

    • Partial tear or degeneration: focal intermediate signal or irregularity of ligament margins

    • Complete tear: discontinuity with bright gap filled by joint fluid

  • T2-weighted images:

    • Normal: low signal (dark) ligament structure

    • Pathology: hyperintense signal within ligament or at attachment sites indicating strain, tear, or edema

    • Bone marrow edema of navicular or cuneiform may appear as bright signal on T2 sequences

    • In chronic injury: thickening and irregular contour with intermediate T2 signal

  • STIR:

    • Normal ligament: low signal (dark)

    • Acute injury: marked hyperintense signal from edema or hemorrhage

    • Best sequence for detecting subtle inflammation or sprain

  • Proton Density Fat-Saturated (PD FS):

    • Normal: thin, dark linear structure at plantar midfoot

    • Tears or sprains: bright linear signal or focal discontinuity at attachment

    • Sensitive for detecting partial tears and soft-tissue edema

  • T1 Fat-Sat Post-Contrast:

    • Normal: minimal enhancement

    • Inflamed or torn ligament: enhancing thickened fibers or enhancement along plantar joint capsule

    • Adjacent tenosynovitis (tibialis posterior) may also enhance, aiding differentiation

CT Appearance

Non-Contrast CT:

  • Ligaments not distinctly visualized but appear as fine soft-tissue densities on the plantar aspect of the cuneonavicular joint

  • Indirect signs: joint space widening, small avulsion fragments, or cortical irregularity at attachment sites

  • Chronic degeneration may show osteophyte formation or subchondral sclerosis of the navicular or cuneiform bones

Post-Contrast CT (standard):

  • Ligament margins slightly better defined due to contrast outlining joint capsule

  • Periligamentous enhancement may indicate inflammation or chronic strain

  • CT helps detect associated bony avulsion fractures not visible on MRI

MRI images

Plantar cuneonavicular ligaments axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI images

Plantar cuneonavicular ligaments coronal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000