Metatarsal interosseous ligaments

At a glance

English

Metatarsal interosseous ligaments

Latin (TA2)

Ligamenta metatarsea interossea

System

Ligament

Region

Foot

Side

Paired, left and right

About the metatarsal interosseous ligaments

The metatarsal interosseous ligaments lie between the bases of adjacent metatarsals, hidden deep to the dorsal and plantar metatarsal ligaments. They are thick bundles of short fibres that connect the rough, non-articular parts of the facing sides of the bases, just in front of the small smooth facets where the bases touch one another. They are found between the lateral four metatarsals; the base of the first is normally not joined to the second in this way.

Because they sit at the front edge of the intermetatarsal joints, they close off the distal part of each joint space. Each intermetatarsal cavity is therefore a narrow slit open behind, where it communicates with the tarsometatarsal joints, and sealed in front by the interosseous fibres. Of the three ligament sets binding the bases, this one is the strongest and does most to hold the bones together.

In function they keep the bases of the metatarsals locked into the transverse arch of the forefoot. They allow small gliding movements as the forefoot adapts to uneven ground, while preventing the bases from spreading apart under load. They work together with the cuneometatarsal interosseous ligaments, including the Lisfranc ligament, which ties the medial cuneiform to the base of the second metatarsal.

Clinically they are part of the ligament complex disrupted in Lisfranc injuries. A fleck of bone torn from the base of a metatarsal, or widening between bases on weight-bearing X-rays, suggests these strong bands have failed. Because they normally resist separation so firmly, such a gap usually means a serious midfoot injury needing specialist treatment.

Attachments and function

Attaches from

Non-articular side of the base of each of the second to fourth metatarsals, just distal to the contact facets.

Attaches to

Facing non-articular side of the base of the next metatarsal, from the third to the fifth.

Function

Form the strongest bond between metatarsal bases, close the intermetatarsal joint spaces in front and resist spreading of the forefoot.

Nerve supply

Twigs of the deep fibular and lateral plantar nerves.

Blood supply

Perforating branches linking the dorsal and plantar metatarsal arteries.