Chopart-Gelenklinie
The midtarsal joint, or Chopart joint, is the articulation between the hindfoot (calcaneus and talus) and the midfoot (navicular and cuboid).
Gross anatomy
The midtarsal joint consists of two joints:
- talocalcaneonavicular joint (often referred to as talonavicular joint): formed by the anterior articular surface of the talus, and a socketlike structure consisting of the posterior articular surface of navicular, talar facets of the anterior part of the calcaneus and part of the spring ligament complex
- calcaneocuboid joint: formed by the anterior articular surface of the calcaneus and the posterior articular surface of the cuboid
Ligaments
- talocalcaneonavicular joint:
- dorsal talonavicular ligament
- spring ligament complex
- calcaneonavicular component of the bifurcate ligament (also known as lateral calcaneonavicular ligament)
- calcaneocuboid joint:
- calcaneocuboid component of the bifurcate ligament (also known as medial calcaneocuboid ligament)
- dorsal calcaneocuboid ligament
- short and long plantar ligaments (often called inferior calcaneocuboid ligament or plantar calcaneocuboid ligament)
Imaging
Radiograph
On lateral and AP views of the foot the talocalcaneonavicular and calcaneocuboid joints are linked together by a smooth curved line also referred to as the cyma line.
The talocalcaneonavicular joint is best visualized on AP and lateral views, whereas the calcaneocuboid joint - on oblique view.
CT
Subtle or non-displaced fractures may be occult on radiographs and often require CT.
MRI
MRI provides excellent visualization of the midtarsal joint ligaments and assessment of their injury.
History and etymology
It is named after Francois Chopart (1743-1795), a French surgeon in Paris . Historically the joint provided a landmark for midfoot amputation in patients with gangrene.