The Chopart joint complex, also known as the midtarsal or transverse tarsal joint, is located between the hindfoot and midfoot and consists of the talocalcaneonavicular and calcaneocuboid joints. Chopart’s fracture-dislocation is a dislocation of the mid-tarsal (talonavicular and calcaneocuboid) joints of the foot, often with associated fractures of the calcaneus, cuboid and navicular. Chopart fracture-dislocations occur at the midtarsal (Chopart) joint in the foot, i.e. talonavicular and calcaneocuboid joints which separate the hindfoot from the midfoot. The commonly fractured bones are the calcaneus, cuboid, and navicular.
Chopart complex injuries (CCIs) are thought to be uncommon; however, recent literature states the rate of misdiagnosis to be between 20 and 41%. Chopart complex injuries are not ankled injuries, with which they are initially confused due to a similar mechanism of trauma in many cases.
Other Names
- Chopart Injury
- Chopart Fracture-Dislocation
- Chopart joint avulsion fracture
- Chopart Complex Injury (CCI)
Pathophysiology
- General
- A rare disease, poorly described in the literature
- The spectrum of isolated soft tissue injury to fracture dislocations depending on etiology
- Only 10-25% are purely ligamentous, most have concomitant fractures
- Sometimes misdiagnosed as lateral ankle sprain due to spontaneous reduction
- Loss of stability jeopardizes the whole function of the foot
Causes
- High energy
- Fracture-dislocations are most commonly due to MVC or fall from height
- The foot is usually dislocated medially and superiorly as it is plantarflexed and inverted
- Low energy
- Twisting force applied to plantarflexed foot[4]
- Avulsion fractures are from low energy trauma
- Crush injury
- Direct blow onto the dorsum of the midfoot may lead to this injury
- Associated with significant neurovascular, soft tissue injuries
Associated Conditions
- Concomitant fractures
- Occur in 75-90% of chopart injuries
- Cuboid Fracture
- Calcaneus Fracture
- Navicular Fracture
Pathoanatomy
- Chopart Joint
- Two articulations connect the hindfoot and midfoot
- The talonavicular joint, calcaneocuboid joint
- Primarily allows for inversion and eversion of the foot
- Talonavicular Joint
- Belongs to the talo-calcaneo-navicular joint (coxa pedis)[5]
- Essential for pronation and supination of the whole foot
- Calcaneocuboid Joint
- Adapts the lateral column of the foot to the plantar buttress
- Adds flexibility to the osteoarticular structure, suspends the pulley of the Peroneus Longus tendon
- Fractures & Osseous Disease
- Traumatic/ Acute
- Talus Fracture
- Calcaneus Fracture
- Traumatic Navicular Fracture
- Cuboid Fracture
- Cuneiform Fracture
- Metatarsal Fracture
- Fifth Metatarsal Fracture
- Toe Fracture
- Hallux Sesamoid Fracture
- Stress Fractures
- Navicular Stress Fracture
- Metatarsal Stress Fracture
- Other Osseous
- Tarsal Coalition
- Accessory Navicular Syndrome
- Traumatic/ Acute
- Dislocations & Subluxations
- Toe Dislocation
- Lisfranc Injury
- Chopart Complex Injury
- Cuboid Syndrome
- Muscle and Tendon Injuries
- Posterior Tibial Tendon Dysfunction
- Peroneal Tendonitis
- Tibialis Anterior Tendinopathy
- Flexor Hallucis Longus Tendinopathy
- Ligament Injuries
- Plantar Fasciopathy (Plantar Fasciitis)
- Turf Toe
- Plantar Plate Tear
- Spring Ligament Injury
- Neuropathies
- Mortons Neuroma
- Tarsal Tunnel Syndrome
- Joggers Foot (Medial Plantar Nerve)
- Baxters Neuropathy (Lateral Plantar Nerve)
- Arthropathies
- Hallux Rigidus (1st MTPJ OA)
- Gout
- Toenail
- Subungual Hematoma
- Subungual Exostosis
- Nail Bed Laceration
- Onychocryptosis (Ingrown Toenail)
- Onychodystrophy
- Paronychia
- Onychomycosis
- Pediatrics
- Fifth Metatarsal Apophysitis (Iselin’s Disease)
- Calcaneal Apophysitis (Sever’s Disease)
- Freibergs Disease (Avascular Necrosis of the Metatarsal Head)
- History
- Patient typically is able to describe an acute mechanism
- Endorses pain, swelling
- Trouble weight bearing
- Deformity may be present
- Physical Exam: Physical Exam Foot
- Large plantar ecchymosis is present (due to rupture of strong plantar ligaments)
- Tenderness along the chopart joint
- Special Tests
Proposed management algorithm for Chopart Injury[6]
Radiographs
- Standard Radiographs Foot
- Often insufficient to make the diagnosis
- Cyma line
- Sign of the smooth joining of the midtarsal joint lines as a “lazy S-shape” of the talonavicular and calcaneocuboid joints
- Can be disrupted in a Chopart Injury
CT
- Useful to delineate osseous injuries
- Fractures
- Dislocations
MRI
- Useful to help
- Evaluate osseous contusions
- Degree of soft tissue involvement
Classification
Main and Jowett Classification
Zwipp Classification
- General
- Most commonly used
- Based upon the affected ligaments and bones
- Type 1. Transligamentous
- Type 2. Transtalar
- Type 3. Transcalcaneal
- Type 4. Transnavicular
- Type 5. Transcuboidal
- Type 6. Combined (any combination of 2–5).
- Make up more than 40% of all Chopart injuries
Treatment
Nonoperative
- Indications
- Ligament only
- Bony contusion
- Extra-articular avulsion
- Non-displaced intra-articular
- Immobilization
- Short Leg Cast for 6 to 8 weeks[7]
- When cast is removed, ankle brace for an additional 6 weeks
- Weight bearing status
- Can allow up to 10 kg of weight bearing for the first 8 weeks
- Consider prophylactic anticoagulation
- Physical Therapy
- Begin when out of cast
- Emphasis lymphatic drainage, strengthening exercises, mobility and flexibility
- Goals: normal gait, prevent stiffness
Operative
- Indications
- Displaced intra-articular
- Dislocation
- Intra-articular impaction
- Combined (Zwipp Type 6)
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