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3 – Congenital foot deformities

Basics of foot

  • DDH is the most common congenital problem of the musculoskeletal system
  • Congenital foot deformities are the second
  • Foot = everything distal to tibiotalar joint
  • Arches of the foot
    • Soft tissues like muscles, tendons and ligaments are important in maintaining the arches of the foot
    • The three arches form a triangle under the foot
    • Transverse arch
    • Lateral longitudinal arch
    • Medial longitudinal arch
  • Characteristics of healthy foot
    • Pain free
    • Good muscle balance
    • No contractures
    • Heel in physiological position (no varus or valgus)
    • Toes without deformity
  • Parts of foot
    • The forefoot is comprised of the metatarsal bones and the phalanges
    • The midfoot is comprised of the navicular, the cuboid, and the cuneiform bones
    • The hindfoot is comprised of the talus and calcaneus
  • Function
    • Dynamic functions
      • The medial structures (talus, navicular, cuneiform and first three metatarsal bones)
      • Provide shock absorption when walking
    • Static functions
      • The lateral structures (calcaneus, cuboid, fourth and fifth metatarsal bones)
      • Provide stability
  • The majority of the pressure is on the calcaneus and the first two metatarsal bones
  • Forefoot deformities
    • Pes adductus (skew-foot)
    • Pes supinatus
  • Hindfoot deformities
    • Often have associated forefoot deformities
    • Clubfoot (talipes equinovarus)
    • Vertical talus (rocker-bottom foot)

22. Clubfoot, etiology and pathology of

  • Clubfoot is one of the two hindfoot deformities (the other being rocker-bottom foot)
    • It is a hindfoot deformity, but it also has associated forefoot deformities
  • Clubfoot is also called congenital talipes equinovarus (CTEV)
  • The clinical appearance involves
    • Concave medial side and convex lateral side
      • Think banana pointing medially
    • Heel varus
    • Adducted and supinated forefoot
    • Can be unilateral or bilateral
  • Congenital clubfoot
    • Common
      • The 2nd most common congenital deformity
    • Incidence depends on race
    • Etiology: Neuromuscular problem
      • Dominant posterior musculature
      • Weak peroneus muscles
      • Shortened Achilles tendon
    • For management of congenital clubfoot: see topic 24
  • Acquired clubfoot
    • Rare
    • Etiology of acquired clubfoot
      • Paralytic causes
        • Paralysis of muscles can cause clubfoot
      • Teratologic (tibia hypoplasia)
      • Syndromic (Larsen/Marfan syndrome)
      • Secondary (arthrogryposis)
      • Postural (mechanical)
        • Due to abnormal intrauterine position of feet
  • Pathology of clubfoot
    • Heel varus and equinus
    • Forefoot adductus and supinatus
    • Concave medial side
    • Convex lateral side
    • The long axis of the talus and calcaneus run parallel to each other in the AP and lateral views

24. Congenital clubfoot, management of

  • See topic 22 for more general information about clubfoot
  • Conservative treatment
    • The conservative technique for treating congenital clubfoot is called the Ponseti method
    • This method is the standard of care, and is successful in almost 100% of cases
    • The Ponseti method takes 4 – 6 weeks
    • Begins as soon as the baby’s skin is ready (can be even after 2 days after birth)
    • Procedure
      • The foot is manually manipulated into a more correct position
        • This type of manipulation is called talus derotation
        • Talus derotation creates an angle between talus and calcaneus
      • The foot is then casted in that position
      • After some days the cast is removed, the foot is once again manipulated and re-casted
      • This procedure is repeated multiple times until the deformity is confirmed corrected by x-ray
      • Achilles tenotomy is finally performed
  • Operative treatment
    • Needed if conservative treatment is unsuccessful
    • Surgical treatment should finish before 12 months of age
  • Aftercare
    • Exercises
    • Follow-up (with x-ray)
      • Taking x-rays is important to determine that the bones are being corrected and not just the soft tissue is being moved
    • Splinting – important to keep the foot in normal position

59. Rocker bottom foot (vertical talus)

  • Rocker-bottom foot (vertical talus) is one of the two hindfoot deformities (the other being clubfoot)
    • Despite being a hindfoot deformity, vertical talus has associated forefoot deformities
  • It is a congenital disorder
  • The clinical appearance involves
    • Concave lateral side and convex medial side
      • Think banana pointing laterally
    • Concave dorsal side and convex plantar side
    • A prominent calcaneus
  • Vertical talus and clubfoot have opposite macroscopic appearance (they’re opposite deformities)
  • Etiology
    • Structural (genetic)
    • Paralytic (neurologic)
    • Teratologic (fibula hypoplasia)
    • Symptomatic (Larsen/Marfan syndrome)
    • Postural (mechanical)
  • Pathology
    • The talus sits vertically instead of normally
    • The angle between the long axis of the talus and calcaneus in the AP view is > 32 degrees
    • The angle between the long axis of the talus and tibia in the lateral view is > 120 degrees
  • Treatment
    • Start with conservative treatment
      • Manipulation + cast (similar to Ponseti method, but in the opposite direction)
      • Check result with X-ray
    • Perform surgery before 1 year of age if results are not satisfactory
      • Surgery of congenital foot abnormalities must be finished before 1 year (before the child will stand)