The plantar tarsometatarsal ligaments are the primary static stabilisers of the Lisfranc joint complex on the plantar side. The plantar Lisfranc ligament (between the medial cuneiform and the second metatarsal base) is the strongest TMT ligament and the last to fail in Lisfranc injuries. The plantar ligaments are stronger than the dorsal TMT ligaments, explaining why Lisfranc dislocations are predominantly dorsal.
| Origin | Plantar surfaces of the cuneiforms and cuboid |
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| Insertion | Plantar bases of the metatarsals |
| Actions | Primary stabilisers of the Lisfranc joint complex from the plantar aspect; resist dorsal metatarsal displacement |
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The plantar Lisfranc ligament (medial cuneiform to second metatarsal base) is assessed on axial MRI — its disruption confirms a high-grade Lisfranc injury requiring ORIF. The plantar bruising sign (plantar ecchymosis at the midfoot after Lisfranc injury) indicates plantar ligament disruption. Weight-bearing radiographs showing any gap between the medial cuneiform and second metatarsal confirm instability.
Plantar TMT ligament complex failure producing Lisfranc instability managed with ORIF or primary arthrodesis for purely ligamentous injuries.
