Foot dislocation

Subtalar dislocation refers to dislocation of the talonavicular and talocalcaneal joints, causing displacement of the calcaneus, cuboid, navicular, and all of the forefoot from the talus. Dislocation most commonly occurs in the medial direction, medially to the talus. This occurs due to high energy trauma, and presents with a foot locked in supination. It’s managed conservatively, with closed reduction and casting.

Lisfranc injury is a dislocation of the tarsometatarsal joint complex and is a relatively rare injury. Fractures may also occur. This type of injury is often overlooked but can give long-term complications like osteoarthritis and disability. Patients have symptoms in the midfoot, and may have plantar ecchymosis. Treatment may be conservative or surgical.

Etiology

Subtalar dislocation is usually caused by high energy trauma.

Lisfranc injury may be caused by high or low energy trauma, typically due to axial load on a plantarflexed foot.

Clinical features

Subtalar dislocation presents with a foot locked in supination (in case of medial dislocation).

Lisfranc injuries cause pain and swelling of the midfoot, and inability to bear weight. Plantar ecchymosis is suggestive but not always present (also present in calcaneal fracture).

Diagnosis and evaluation

X-ray is often sufficient, but CT or MRI may be necessary.

Treatment

Subtalar dislocation is managed with closed reduction and cast immobilisation. Sometimes temporary (4 weeks) pinning of the joints may be necessary.

Closed, nondisplaced Lisfranc injuries are managed with closed reduction and casting. Displaced fractures are managed with open reduction and fixation with screw or K-wire.