Foot injuries

Anatomy

• Three sections: Hindfoot, midfoot and forefoot
  • Hindfoot = Calcaneus and talus
  • Midfoot = Medial, middle and lateral cuneiforms + navicular + cuboid
  • Forefoot = Metatarsals and phalanges
• Chopart joint: Separates hindfoot from midfoot
• Lisfranc joint: Separates midfoot from forefoot

Calcaneus injuries

• Typically large forces like axial load with associated injuries
  • 10% cervical or lumbar crush
  • 25% other limb injury
  • Pelvic fractures also common
• Intra-articular and extra-articular

Calcaneal injuries

• Diagnosis
  • Boehler angle = Line drawn from highest part of anterior process of calcaneus and highest point of posterior articular surface + line drawn from highest point of posterior articular surface of calcaneus and most superior part of calcaneal tuberosity
  • 25-40 degrees is normal. <25 degrees suggests fracture
  • <20 degrees 100% sensitive and specific

Bohler angle

Calcaneal injuries

• CT can provide far more clarity and sensitivity for fracture
• Treatment
  • Intra-articular: Ortho consult, posterior splint, strict elevation, NWB and analgesia
  • Displaced fractures usually internally fixated
  • Extra-articular: Analgesia, elevation, immobilisation and ortho follow-up

Talus injuries

• Typically high-energy trauma
• Major talus fractures involve head, neck or body and can result in AVN
• Minor talus fractures do not cross central portion
  • Osteochondral fracture on dome
  • Lateral process
  • Posterior process
• Lateral talar process fracture = Snowboarder’s ankle and often mistaken for lateral ankle sprain
• CT is most sensitive
• Minor talus fractures – Posterior splint, NWB, analgesia and # clinic
• Major talus fractures – Ortho consult in ED

Talus injuries

• Subtalar dislocations of talus
  • Tibiotalar joint remains intact while talocalcaneal and talonavicular joints dislocated
  • 1-2% of ankle dislocations
  • May be medial, lateral, anterior or posterior (medial 75%)
  • Closed reduction and slab with ortho consult
  • May require GA for reduction

Lisfranc injuries

• Midfoot has two columns
  • Medial column: Navicular, three cuneiforms and first three tarsometatarsal joints
  • Lateral column: Cuboid and lateral two tarsometatarsal joints
• Untreated midfoot injuries lead to great disability and Charcot foot in diabetics
• Lisfranc ligament runs between lateral base of medial cuneiform and medial base of 2^nd metatarsal

• Can be sprain through to fracture-dislocation often with coexisting hind and forefoot fractures (esp. second metatarsal)
  • Sprain typically low energy indirect force
  • Plantarflexion with axial load causes more serious injuries
  • Forced dorsiflexion in high-speed MVA with foot on pedal

• Diagnosis
  • Initially missed in 20%
  • Pain with torsion of midfoot
  • Injuries about the tarsometatarsal joint with pain on passive dorsi- or plantarflexion of foot
  • X-ray should at minimum include a weight-bearing AP, lateral and 30 degree oblique view
  • Bony displacement >1mm between 1^st and 2^nd metatarsals is considered unstable
  • Plain film only 70% sensitive (gap sign seen in 90% of injuries though…)
  • 5 signs of Lisfranc injury
    • Discontinuty of line drawn from base of 2nd metatarsal to medial side of middle cuneiform on AP
    • Widening of space between 1st and 2nd rays on AP
    • Dorsal displacement of proximal base of 1st or 2nd metatarsal on lateral view
    • Medial side of base of 4th metatarsal does not line up with medial side of cuboid on oblique view
    • Disruption of medial column line on oblique view
  • CT is ideal as diagnoses occult fractures and subluxations not seen on plain films

Lisfranc injuries

• Severity grading (Nunley)
  • Type I – Non-displaced
  • Type II – Diastasis between 1^st and 2^nd metatarsal heads
  • Type III – Diastasis and loss of arch height
• Treatment
  • Non-displaced – NWB backslab, rest, ice, elevation and # clinic
    • At 6 weeks, gradual progressive weight bearing often initiated
  • Displaced – Unstable and need ortho consult and anatomic reduction
  • Reduction
    • Reduce the 1st metatarsal/cuneiform articulation and the rest should follow

Lisfranc injury

Lisfranc injury

Navicular injuries

• Imaging should include bilateral weight-bearing AP, lateral and oblique
• CT best for talonavicular articulation
• Non-displaced – NWB short leg cast for 6-8 weeks with fracture clinic
• Displaced – Ortho consult in ED
• At risk of AVN and instability leading to arch collapse

Cuboid injuries

• Weight-bearing views
• Non-displaced – Short-leg case and NWB
• Comminuted – Ortho consult

Cuneiform injuries

• Isolated cuneiform injuries are very rare but can occur with other fractures from high-energy trauma
• Medial cuneiform – surgery
• Middle or lateral cuneiform – Closed reduction and cast usually sufficient

Fifth metatarsal

• Proximal 5th
  • Zone 1: Hindfoot inversion (Pseudojones)
    • Proximal tubercle proximal to 4^th/5^th metatarsal joint
    • May enter metatarso-cuboid joint
    • Treat with walking cast/moonboot and weight bear as tolerated with # clinic f/u
  • Zone 2: Forefoot adduction (Jones)
    • Metaphyseal/diaphyseal fractures – High risk of AVN as vascular watershed and non-union at level of joint
    • Usually 1.5-2cm from proximal tuberosity
    • Enters 4^th-5^th metatarsal joint
    • 35-50% non-union rate
    • Treat with backslab and fracture clinic referral
  • Zone 3: Repetitive microtrauma stress
    • Backslab and fracture clinic as also prone to non-union

Fifth metatarsal

Forefoot injuries

• Metatarsal injuries
  • 1^st through 4^th – must exclude Lisfranc
  • Isolated proximal metatarsal fracture backslab and # clinic
    • Even if lateral/medial displacement
  • Non-displaced isolated shaft metatarsal fractures – Posterior splint, moonboot or surgical shoe with fracture clinic referral
  • Displacement >3-4mm or angulation >10 degrees in dorsal/plantar directions require surgical reduction
  • Risk of compartment syndrome
  • Multiple metatarsal fractures need consult unless non-displaced and stable
  • 1^st metatarsal fractures are less well tolerated so get consult unless non-displaced

Metatarsophalangeal injuries

• Turf toe
  • Sprain with hyperdorsiflexion of first MTP joint while foot remains in plantarflexion
  • Capsular avulsion on X-ray
  • Rest, ice, elevation and reinforced shoe
• Dislocations 
  • Can occur and need reduction (closed or open)

Phalanx injuries

• X-ray not even necessary for 2-5^th phalangeal fractures unless other reason
• Buddy taping and hard-soled shoe

Freiburg disease

• Avascular necrosis of the 2^nd metatarsal
• Physical stress results in multiple tiny fractures where shaft meets growth plate with impaired blood flow to head of metatarsal
• 80% young women
• Usually conservatively managed with reduced stress through foot

Last Updated on October 28, 2020 by Andrew Crofton