Calcaneonavicular coalition

Dr Bahman Rasuli and Dr Alexandra Stanislavsky ◉ et al.

Calcaneonavicular coalition is one of the two most common subtypes of the tarsal coalition, the other being talocalcaneal coalition. As with any coalition it may be osseous (synostosis), cartilaginous (synchondrosis) or fibrous (syndesmosis).

Radiographic features

This type of coalition is more easily diagnosed on plain film than talocalcaneal coalition.

Plain radiograph

Oblique view

best at depicting calcaneonavicular coalition directly as a calcaneonavicular bar

AP view

may also directly show the coalition
indirect signs include
- the broad proximal surface of navicular: broader than the articulating talar head
- lateral tapering of navicular

Lateral view

Indirect signs include:

anteater sign: an elongated anterior process of the calcaneus
reverse anteater sign: elongated lateral navicular
talar beak
short talar neck

CT

CT can be used to confirm the diagnosis where this was equivocal or not seen on plain films. It may also be used for surgical planning.

MRI

MRI is probably more helpful in assessing and characterizing cartilaginous and fibrous coalition and allows assessment of associated bone and soft tissue edema.

Treatment and prognosis

As with any tarsal coalition, non-operative management may allow some improvement in symptoms initially, but they usually return. Usually, surgical treatment with excision of the coalition is required.

References

Anatomy: Lower limb

Anatomy: Lower limb

skeleton of the lower limb
joints of the lower limb
- hip joint
  - ligaments
  - additional structures
  - ossification centers
- knee joint
- tibiofibular joints
  - proximal tibiofibular joint
  - distal tibiofibular syndesmosis
    - ligaments
      - anterior inferior tibiofibular ligament
        accessory anterior inferior tibiofibular ligament
      - posterior inferior tibiofibular ligament
- ankle joint
  - regional anatomy
    - medial ankle
    - lateral ankle
    - anterior ankle
  - ligaments
    - medial collateral (deltoid) ligament
    - lateral collateral ligament
    - additional structures
    - ankle bursae
      - retrocalcaneal bursa
      - subcutaneous calcaneal bursa
    - ossification centers of the ankle
  - variants
    - ball and socket ankle joint
- foot joints
  - subtalar joint
    - articulations
      - talocalcaneal joint
    - ligaments
    - associated structures
  - mid-tarsal (Chopart) joint
    - talonavicular joint
    - calcaneocuboid joint
  - tarsometatarsal (Lisfranc) joint
    - ligaments
      - Lisfranc ligament
  - intermetatarsal joint
  - metatarsophalangeal joint
  - interphalangeal joint
spaces of the lower limb
- adductor canal
- femoral sheath
  - femoral canal
    - femoral ring
- femoral triangle (contents mnemonic | boundaries mnemonic)
- foot subdivisions
- popliteal fossa (mnemonic)
- tarsal tunnel (mnemonic)
- triangular space of cruciate ligaments
muscles of the lower limb
- muscles of the pelvic group
  - inner hip group
    - iliopsoas muscle
  - gluteal region
  - lateral rotator group
- muscles of the thigh
- muscles of the leg
  - anterior compartment of the leg
  - posterior compartments of the leg
    - superficial posterior compartment of the leg (calf)
      - triceps surae
        
        medial and lateral heads of the gastrocnemius muscle
        
        soleus muscle
        accessory soleus muscle
      - plantaris muscle
      - calcaneal tendon
    - deep posterior compartment of the leg
  - lateral compartment of the leg
    - peroneus brevis muscle
    - peroneus longus muscle
- muscles of the foot
  - dorsal muscles
    - extensor hallucis brevis muscle
    - extensor digitorum brevis muscle
  - plantar muscles
    - 1st layer
    - 2nd layer
      - quadratus plantae muscle
      - lumbrical muscles
    - 3rd layer
    - 4th layer
      - dorsal interossei muscles
      - plantar interossei muscles
- accessory muscles
  - accessory peroneal muscles
vascular supply of the lower limb
- arterial supply of the lower limb
- venous drainage of the lower limb
  - deep system
    - common femoral vein
      - femoral vein
        
        deep femoral vein
        
        popliteal vein
        
        peroneal vein
        
        posterior tibial vein
        
        anterior tibial vein
  - superficial system
    - great saphenous vein
      - dorsal venous plexus
    - small saphenous vein
      - vein of Giacomini
innervation of the lower limb
- lumbar plexus (mnemonic)
  - femoral nerve
    - saphenous nerve
  - obturator nerve
- sacral plexus
  - sciatic nerve (motor distribution)
    - common peroneal nerve
      - superficial peroneal nerve
      - deep peroneal nerve
    - tibial nerve
lymphatic system of the lower limb
- lymphatic pathways
  - anteromedial group
  - anterolateral group
  - posteromedial group
  - posterolateral group
- lower limb lymph nodes
  - inguinal lymph nodes
    - superficial inguinal lymph nodes
    - deep inguinal lymph nodes
  - popliteal lymph nodes

Article information

rID: 14217

System: Musculoskeletal

Section: Anatomy

Tag: foot

Synonyms or Alternate Spellings:

Calcaneo-navicular coalition

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