Topics

Topic

design image
Interosseous cuneometatarsal Ligament (Lisfranc Proper Ligament)

The interosseous cuneometatarsal ligament, also known as the Lisfranc proper ligament, is a strong oblique ligament that connects the lateral surface of the medial cuneiform to the base of the second metatarsal. It forms the key stabilizing structure of the Lisfranc joint complex, preventing separation between the medial cuneiform and the second metatarsal base.

This ligament is short, thick, and oriented obliquely, lying deep within the first intermetatarsal space. It is crucial for maintaining midfoot stability and ensuring the integrity of the tarsometatarsal articulation. Rupture or avulsion of the Lisfranc ligament results in a Lisfranc injury, which can cause severe midfoot instability, diastasis between metatarsal bases, and long-term degenerative arthritis if undiagnosed or untreated.

Synonyms

  • Lisfranc ligament

  • Interosseous cuneometatarsal ligament

  • Medial cuneiform–second metatarsal interosseous ligament

Relations

  • Superiorly: Dorsal cuneometatarsal ligaments and dorsal Lisfranc joint capsule

  • Inferiorly: Plantar cuneometatarsal ligaments and interosseous fascia

  • Medially: Medial cuneiform

  • Laterally: Base of the second metatarsal

  • Anteriorly: Deep transverse metatarsal ligament

  • Posteriorly: Second tarsometatarsal joint space and adjacent interosseous tissue

Origin, Course, and Insertion

  • Origin: Lateral surface of the medial cuneiform bone

  • Course: Runs obliquely downward and laterally within the first intermetatarsal space

  • Insertion: Medial base of the second metatarsal bone

Function

  • Primary stabilizer of the Lisfranc joint complex (medial cuneiform–second metatarsal articulation)

  • Prevents separation of the first and second metatarsals under load

  • Maintains midfoot arch integrity during weight-bearing and push-off phases of gait

  • Transfers load between the medial and central columns of the foot

  • Resists twisting or shearing forces at the tarsometatarsal joint

Clinical Significance

  • Lisfranc injury: Tearing or avulsion of this ligament causes midfoot instability and diastasis between the medial cuneiform and second metatarsal

  • Mechanism: Usually due to axial loading with forefoot plantarflexion (e.g., twisting fall, sports injury, motor accident)

  • Radiographic clue: Widening between the bases of the first and second metatarsals

  • Symptoms: Midfoot pain, swelling, inability to bear weight, tenderness over Lisfranc joint

  • Complications: Post-traumatic arthritis, arch collapse, and chronic midfoot pain if untreated

  • Imaging relevance: MRI is the gold standard for identifying partial or complete Lisfranc ligament tears and associated bone marrow edema or joint malalignment

Nerve Supply

  • Supplied by deep fibular (peroneal) nerve branches innervating the dorsal midfoot region

MRI Appearance

  • T1-weighted images:

    • Normal ligament: low signal (dark band) between the medial cuneiform and second metatarsal

    • Partial tear: focal thickening and intermediate signal within the ligament

    • Complete rupture: discontinuity or absence of the low-signal band with interposed fluid or fat signal

    • Associated bone marrow edema in cuneiform or second metatarsal base may appear as intermediate-to-bright signal

  • T2-weighted images:

    • Normal ligament: low to intermediate signal, appearing darker than surrounding muscle

    • Partial tear: hyperintense linear signal within the ligament substance

    • Complete tear: high-signal gap between the medial cuneiform and second metatarsal

    • Secondary signs: joint fluid, edema, or subluxation at the tarsometatarsal joint

  • STIR (Short Tau Inversion Recovery):

    • Normal ligament: dark, continuous band

    • Pathology: bright hyperintense signal indicating edema, partial tear, or complete disruption

    • Surrounding bone marrow edema in cuneiforms and metatarsals enhances detection of acute injuries

  • Proton Density Fat-Saturated (PD FS):

    • Normal: well-defined dark ligament

    • Partial tear: localized bright signal within or around the ligament

    • Complete tear: full-thickness bright defect with surrounding edema

    • Excellent for subtle ligament injury or sprain identification

  • T1 Fat-Sat Post-Contrast:

    • Normal ligament: minimal or no enhancement

    • Partial tear or inflammation: enhancement at ligament margins

    • Complete rupture: enhancing granulation tissue or scar formation in chronic stages

CT Appearance

Non-Contrast CT:

  • Ligament itself not directly visualized but inferred from bone relationships

  • Indirect signs: widening between medial cuneiform and second metatarsal base (>2 mm)

  • Associated findings: small avulsion fragments, malalignment, or subtle dislocation at tarsometatarsal joint

  • Chronic injury: sclerosis and osteophyte formation at Lisfranc articulation

Post-Contrast CT (standard):

  • Ligament remains indistinct, but surrounding soft tissue changes or enhancement can suggest inflammatory repair or scarring

  • Used to assess alignment, fracture fragments, and joint congruity in post-traumatic evaluation

MRI image

Interosseous cuneometatarsal Ligament (Lisfranc Proper Ligament) axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI image

Interosseous cuneometatarsal Ligament (Lisfranc Proper Ligament) coronal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000