Chopart's fracture-dislocation is a dislocation of the mid-tarsal

Tarsus (skeleton)

In tetrapods, the tarsus is a cluster of articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. In the foot the tarsus articulates with the bones of the metatarsus, which in turn articulate with the bones of the individual toes...

 (talonavicular and calcaneocuboid) joints of the foot

Foot

The foot is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made up of one or more segments or bones, generally including claws...

, often with associated fractures

Bone fracture

A bone fracture is a medical condition in which there is a break in the continuity of the bone...

 of the calcaneus, cuboid and navicular

Navicular bone

The navicular bone is a small bone found in the feet of both humans and horses.- Human anatomy :The navicular bone is one of the tarsal bones, found in the foot. Its name derives from the bone's resemblance to a small boat, caused by the strongly concave proximal articular surface...

.

Mechanism of injury

Chopart's fracture-dislocation is usually caused by falls from height, traffic collisions and twisting injuries to the foot as seen in basketball

Basketball

Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...

 players.

Injury patterns

• The foot is usually dislocated medially (80%) and superiorly, which occurs when the foot is plantar flexed
  Plantarflexion
  Plantarflexion is the movement which increases the approximate 90 degree angle between the front part of the foot and the shin, as when depressing an automobile pedal...
  
   and inverted
  Inversion (kinesiology)
  Inversion is the movement of the sole towards the median plane .Tibialis anterior and tibialis posterior invert. Some sources also state that the triceps surae and extensor hallucis longus invert....
  
  .
• Lateral displacement occurs during eversion
  Eversion (kinesiology)
  Eversion is the movement of the sole of the foot away from the median plane. It occurs at the subtalar joint.Peroneus longus and peroneus brevis evert. Both muscles are innervated by the superficial fibular nerve....
  
   injuries.
• Associated fractures of calcaneus, cuboid and navicular are frequent.
• Open fractures occur in a small percentage.

Diagnosis and treatment

Diagnosis is made on plain radiograph of the foot, although the extent of injury is often underestimated.

Treatment comprises early reduction of the dislocation, and frequently involves open reduction internal fixation to restore and stabilise the talonavicular joint. Open reduction and fusion of the calcaneocuboid joint is occasionally required.

Prognosis

With prompt treatment, particularly open reduction, and early mobilisation the outcome is generally good. High energy injuries and associated fractures worsen the outcome.