![]() ![]() They may also be seen in the 3 rd metatarsal, 1 st or 2 nd cuneiform, or navicular bones. Other possible findings are malalignment between the lateral border of the base of the 1 st metatarsal and the lateral border of the medial cuneiform malalignment between the medial border of the base of the 4 th metatarsal and the cuboid (on the oblique view) increased distance between the medial cuneiform and the 2 nd metatarsal and increased distance between the medial and intermediate cuneiforms (C2) 13.Īssociated fractures most often occur at the base of the second metatarsal, seen as the fleck sign. An additional abnormality is diastasis >2 mm between the 1 st and 2 nd metatarsal bases 10. The key finding is malalignment of the second tarsometatarsal joint, such as lateral displacement of the second metatarsal base on AP view and/or dorsal step-off sign on lateral view 10. CT is, however, favored as it will also demonstrate unsuspected associated fractures. Still, subtle injuries may be missed and require further imaging such as CT, MRI or radiographic stress views with forefoot abduction. These injuries are well demonstrated on the standard views of the foot. Radiographic features Plain radiograph/CT isolated: this involves one or two metatarsals that dislocate dorsally in isolation.divergent: a divergent injury is a lateral dislocation of the 2 nd to 5 th metatarsals with medial dislocation of the 1 st metatarsal. ![]() homolateral: a homolateral injury is a lateral displacement of the 1 st to 5 th metatarsals or of 2 nd to 5 th metatarsals where the 1 st MTP joint remains congruent.There are several types of Lisfranc fracture-dislocation: Tarsometatarsal dislocation may also occur in the diabetic neuropathic joint ( Charcot). forced plantar-flexion where the plantarflexed foot undergoes significant axial loading.with cleats or football boots (this is the classic 'horse stuck in stirrup mechanism) forefoot abduction-type injuries where the hindfoot is fixed and there is rotation around the joint such as changing direction with a foot planted firmly i.e.direct crush injury or an indirect load onto a plantarflexed foot 3.Injury mechanisms are varied and include: The Lisfranc ligament complex is particularly vulnerable due to the absence of transverse ligaments stabilizing the 1 st and 2 nd metatarsals. ![]() Its integrity is crucial to the stability of the Lisfranc joint. The ligament helps wedge the base of the 2 nd metatarsal base between the medial and lateral cuneiforms creating a keystone-like configuration, 'locking' the tarsometatarsal joint in place and acting as a key transverse stabilizer of the foot. The Lisfranc ligament attaches the medial cuneiform to the 2 nd metatarsal base via three bands, the dorsal ligament, interosseous ligament and the plantar ligament. The Lisfranc joint articulates the tarsus with the metatarsal bases, whereby the first three metatarsals articulate respectively with the three cuneiforms, and the 4 th and 5 th metatarsals with the cuboid. ![]()
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