Cuneometatarsal interosseous ligaments

At a glance

English

Cuneometatarsal interosseous ligaments

Latin (TA2)

Ligamenta cuneometatarsea interossea

System

Ligament

Region

Foot

Side

Paired, left and right

About the cuneometatarsal interosseous ligaments

The cuneometatarsal interosseous ligaments lie inside the tarsometatarsal joint complex, where the three cuneiforms and the cuboid meet the bases of the five metatarsals. Instead of covering the joints on the surface, they run between bones in the depth of the joint line, from the side of a cuneiform to the side of a neighbouring metatarsal base.

The most important of them is the medial one, usually called the Lisfranc ligament. It runs obliquely from the lateral surface of the medial cuneiform to the medial side of the base of the second metatarsal. This matters because the base of the second metatarsal is set back between the medial and lateral cuneiforms, like a keystone in a mortise, and there is normally no strong ligament linking the bases of the first and second metatarsals. The Lisfranc ligament is therefore the main tie between the first ray and the rest of the forefoot. Other interosseous bands join the lateral cuneiform to the adjacent metatarsal bases.

Together with the dorsal and plantar tarsometatarsal ligaments, these ligaments make the joints between the cuneiforms and the medial metatarsals almost rigid. They hold the base of the forefoot as a stable platform for push-off in walking and running and help maintain the transverse and medial longitudinal arches.

Injury to the Lisfranc ligament is clinically important. It may follow a twist on a pointed, loaded foot, as in sport or when a foot is caught in a stirrup, or a high-energy crush. The second metatarsal then separates from the medial cuneiform, sometimes with a small avulsed fleck of bone. These injuries are easily missed on plain X-rays; if they go untreated, the midfoot can collapse and become arthritic.

Attachments and function

Attaches from

The lateral surface of the medial cuneiform and the facing surfaces of the lateral cuneiform.

Attaches to

The facing sides of the bases of the metatarsals, above all the medial side of the base of the second metatarsal.

Function

Bind the cuneiforms to the metatarsal bases, make the tarsometatarsal joints of the medial forefoot nearly rigid and support the arches; the Lisfranc ligament ties the first ray to the second metatarsal.