Talipes Equinovarus

Definition

Congenital deformity of the foot with

  • Equinus & varus deformity of heel
  • Forefoot adduction
  • Midfoot supination

Epidemiology

  • Commonest of the congenital orthopaedic abnormalities
  • 1.5:1000 live births
  • Males>Females – 2:1
  • 30-50% bilateral
  • Much more common in Polynesian & Maori & lower in Asians
  • Wynne-Davies suggests that has polygenic inheritance
  • Tachdjian suggests that
  • Patient with CTEV that has one child affected then 25% chance of another affected
  • If both parents are normal & have affected child then chance of another is 5%

Classification

  • Idiopathic or Secondary
  • Idiopathic
    • Multifactorial
    • Polygenic
    • Enviromental
    • Multifactorial inheritance patterns
    • 0.5% if one 2nd degree relative (aunt, uncle) has CTEV
    • 2% if one parent has CTEV
    • 5% if one child has CTEV
    • 25% if one parent & one child has CTEV
    • Enviromental
    • Uterine constriction (Oligohydramnios, Constriction Band)
    • Drugs/ Chemicals (Aminopterin, Tubocurarine)
  • Secondary
    • Genetic
    • Part of syndromes with Mendelian Inheritance
    • Craniofacial dysplasia
    • Diastrophic dwarfism
    • Larsens syndrome
    • Pierre-Robin
    • Neuromuscular
    • Associated with
    • Spina Bifida
    • Cerebral Palsy
    • Arthrogryposis
    • Muscular Dystrophies
    • Spinal Muscular Atrophy

Pathogenesis

  • Unknown at this stage
  • Various theories
  • Irani & Sherman 1972 – suggest abnormal cartilage anlage in anterior aspect of talus secondary to germ cell defect
  • Isaacs in 1977 – found histochemical muscle abnormalities under EM but not detectable on EMG
  • Atlas 1980 – found abnormal vascular abnormalities with ischaemic area in sinus tarsi region & this suggests an abnormality with blood supply to tarsal neck region
  • Dietz 1983 – Posterior tibial tendon sheaths have significantly less cellular & cytoplasmic volume than those anteriorly
  • Zimmy et al 1988 – found regional differences in the cellular nature of the fascia in clubfoot – medial fascia contained cells resembling myofibroblasts & mast cells
  • Victoria-Diaz 1984 – there may be defect in tibial growth phase & so production of clubfoot deformity
  • In summary » Postulated to be due to
  • Primary germ plasm defect
  • Cartilage anlage arrest
  • Abnormal myofibroblasts
  • Abnormal neuromuscular junction
  • Retracting fibrosis
  • Anomalous tendon insertions
  • Ischaemia
  • Packaging defect (oligohydramnios)

Pathology

  • All tissues around the foot are abnormal
  • Bones
  • All the bones of foot abnormal
  • No internal tibial torsion
  • Femur, Tibia & the fibula especially often shorter
  • Talus
  • Head & neck deviated medially & plantarward
  • Body rotated externally in the ankle mortise
  • Body extruded anteriorly
  • Smaller than normal
  • Calcaneum
  • In equinus
  • Rotated medially
  • Means that long axis of talus & calcaneum parallel
  • Smaller than normal
  • Navicular
  • Subluxed medially towards the medial malleolus
  • Cuboid
  • Subluxed medially
  • Forefoot
  • Adducted & Supinated
  • Cavus deformity may occur
  • Lateral Malleolus
  • Located posterior near the calcaneus
  • Muscles
  • Atrophy & contracture
  • Triceps Surae
  • Tibialis Posterior
  • FHL
  • FDL
  • Tendon sheaths thickened around
  • Tibialis Posterior
  • Peroneals
  • Ligaments & Fascia
  • Shortening of
  • Calcaneofibular ligament
  • Posterior Talofibular ligament
  • Deltoid
  • Long & Short plantar ligaments
  • Spring
  • Bifurcate
  • Plantar fascia
  • Tendo Achilles with more medial insertion on the calcaneum » ↑ varus
  • Joint Capsules
  • Contracture of capsules of
  • Posterior ankle joint
  • Posterior subtalar joint
  • Talonavicular joint
  • Calcaneocuboid joint

Clinical Features

  • Clubfoot
  • 1. Deformity
    • Heel equinus
    • Heel varus
    • Midfoot supination
    • Forefoot adduction
    • Maybe cavus
  • 2. Features
    • Curved lateral border of foot
    • Devil’s thumbprint over the lateral malleolus
    • Medial & Lateral skin creases
    • Navicular fixed to medial malleolus
    • Os calcis fixed to the lateral malleolus
    • Heel small & high
  • 3. General
    • Calf atrophy
    • Calf shortening
    • Other Conditions
    • Should all be excluded
    • Spinal Dysraphism
    • Arthrogryposis
    • Neuromuscular Disorders
    • When examining patient for first time assessment made of the degree of correction able to be achieved
    • Mild
    • Able to correct past neutral
    • Postural Form of deformity
    • 10% require surgery
    • Moderate
    • Correction within 20° of neutral
    • Structural Form
    • 50% require surgery at some stage
    • Severe
    • Correction to < 20° of neutral
    • Severe structural abnormalities – Teratogenic
    • 90% require surgery

Radiology

  • Can assess prior to treatment with A-P & Lateral of foot
  • Calcaneal & Talar ossification centres are present at birth with the cuboid appearing by 6 months
  • Navicular will not appear until 2-4 years
  • Simons CORR 1978 – suggested standard radiographic assessment
  • Anteroposterior View
  • Kites angle – Anteroposterior Talocalcaneal angle
  • Ankle dorsiflexed 15° & tube at 30° from vertical
  • Talocalcaneal angle normally 20-40°
  • Less than 20° suggests the talus & calcaneum are becoming more parallel
  • Suggested that with nonoperative management the correction of equinus should be delayed until the Kite angle is normalised to avoid breaking midfoot
  • First Metatarsal-Tarsal Angle
  • Line through the long axis of first metatarsal & the talus respectively allows evaluation of the degree of forefoot adduction
  • Normal angle is 0-20°
  • Lateral View
  • Lateral Talocalcaneal Angle
  • Angle formed by line drawn through the long axis of talus & line along the plantar aspect of the calcaneum
  • Normally is 35-55°
  • < 35° indicates hindfoot equinus
  • Talocalcaneal Index
  • Addition of the Talocalcaneal angles in A-P & Lateral
  • Normally > 40°

Treatment

  • Initially non operative & starts on Day One of life » “as the feet exit the birth canal”
  • Aims of treatment
    • Correct deformity early
    • Correct fully
    • Maintain in corrected position until foot stops growing
    • Remember two types of club foot – Attenborough 1966
    • Easy
    • Resistant
    • The resistant form identified by
    • Thin calf
    • Small high heel
    • Medial crease
    • Devil’s thumb print laterally
    • (ie seen with Arthrogryposis)
  • 1. Non operative Treatment
    • The First Cast
    • Correct the heel varus & forefoot adduction first – avoid breaking the midfoot
    • One hand on knee & one on toes & manipulate into neutral position
    • Then apply firm SLPOP over the holders fingers & apply knob at the end for ease of removal
    • Moulding until sets
    • Repeat these second daily until the forefoot adduction is neutral – usually at 1 week
    • First LLPOP
    • Heel equinus corrected with this
    • SLPOP applied with gentle correction of equinus – push calcaneus upwards & heel downwards & avoid pushing on midfoot
    • Then extend as LLPOP with knee flexion & slight ER
    • Subsequent casts applied at 3 days then weekly depending on progress
    • This is repeated until the forefoot adduction & heel equinus corrected beyond neutral – ie Overcorrect
    • Usually at 3 week time
    • The last cast applied in full correction for further 3 weeks
    • Then strapping & manipulation by the physiotherapists up to 12 weeks
    • Splintage
    • Bivalved AFO (front-back boots) & Dennis-Browne bar used full-time until walking age
    • Removed to learn walking
    • Applied when resting only up to 18 months
    • Review
    • See serially up to 8 years
    • Outcome
      • 50% of the feet are corrected by 6 weeks at end of casting
      • 90% of mild
      • 50% of moderate
      • 10% of the severe
    • If no correction then surgery required & no further non op treatment until surgery
  • 2. Surgical Treatment
    • Indications
      • Failure of serial casting at 6 weeks
      • Failure of subsequent splintage & strapping
      • Timing
      • Variable timing in literature
      • Probably average is 3-9 months
    • Advantage of
      • Prior to fixed bony deformity & contractures
      • Prior to walking
      • There is literature to support later surgery at one year as anatomy more able to be recognised
  • Goals
    • Release of all soft tissue restraints to allow proper positioning of the tarsal bones
  • Approaches
    • 1. Turco
      • Posteromedial incision – curved
      • From the base of first MT above the posterior tubercle of calcaneus to the TA
      • The disadvantages include
      • Crosses medial skin creases
      • Difficult to explore the plantar fascia
      • Difficult to explore the posterolateral corner
      • May need a separate lateral incision particularly in older child
    • 2. Cincinnati
      • Posterior U shaped incision from the navicular medially curved posteriorly in the skin crease & ending at the calcaneocuboid joint
      • Lateral exposure available with this approach
      • Disadvantages
      • Fear of loss of the posterior skin flap
      • Exposure of the plantar fascia difficult
      • Difficult to expose the proximal TA
    • 3. Norris-Carrol
      • Two incisions performed
      • Curved incision from centre of os calcis to the talonavicular joint
      • Second incision halfway between the TA & the lateral malleolus
      • The disadvantage is two incisions
  • Surgical Procedures
    • Identify the N-V bundle & protect
    • Posteromedial Release
    • Z lengthening of the TA
    • Posterior capsulotomy of
    • Ankle joint
    • Subtalar joint
    • Release the Posterior tibiofibular ligament & the Calcaneofibular ligament
    • FHL – intermuscular recession if the hallux flexes when foot dorsiflexed
    • FDL – Z-lengthening if the lesser toes flex when foot dorsiflexed
    • The above done at end of procedure if required
    • Often the above is all that required
    • Medial release follows if there is persistent varus
    • Z-lengthening of the Tibialis Posterior & release of sheath
    • Follow to the navicular insertion & this is guide to T-N joint
    • The capsule of the T-N joint released
    • The superficial fibres of the Deltoid ligament & the Spring ligament released
    • At this stage usually able to reduce the navicular – if not then lateral release often required
    • Plantar Release
    • Usually if resistant cavus
    • Able to reflect the Abductor Hallucis
    • Release the
    • Knot of Henry
    • Long plantar ligament
    • Plantar Fascia
    • FDB from the calcaneum
    • The calcaneocuboid capsule
    • Medial ST joint released
    • Lateral Release
    • Usually severe forms where complete correction of the forefoot adduction not correctable with medial release
    • Release the
    • Bifurcate ligament
    • Calcaneocuboid capsule
    • Interosseus ligament
    • Allows the calcaneocuboid joint to reduce independently to the talonavicular joint & correct the forefoot adduction & supination of midfoot
    • Supplemental Fixation
    • K-wire fixation across the
    • Talonavicular joint
    • Calcaneocuboid joint
    • Subtalar joint
    • Maybe required to hold position
    • Postoperative Care
    • LLPOP – in equinus if Cincinnati to protect the skin
    • Neutral if other incisions
    • ROS & take out wires at 2 weeks
    • Then cast until 6 weeks
    • Splintage as per non op treatment then
    • Results
    • Ponsetti 1963 – 71% good or excellent results
    • Turco 1979 – 84% good or excellent results with posteromedial release
    • Recurrence/ Failure
    • 15% of operated clubfoot
    • Not really recurrence rather
    • Undercorrection
    • Failure to maintain correction
    • Prevented by
    • Explanation preop about need for ongoing care
    • Adequate initial correction
    • Postoperative vigilance
    • Suspect early with tight TA & stiff ST joint
    • Usually see
    • Forefoot adductus
    • Hindfoot varus
    • Curved lateral border of foot
    • Cavus
    • Younger than 2-3 years then can repeat the release
    • Difficult +++
    • Relatively high risks
    • Benefits ↓ with advancing age
    • May need to add lateral release or lateral column shortening
    • If > 5 years then may need bony procedures to realign the forefoot or os calcis
    • Forefoot Adductus
    • Dynamic
    • Correctable passively
    • Best seen in swing phase
    • Correct with SPLATT
    • Transfer the lateral 1/2 of the Tibialis Anterior to lateral cuneiform or cuboid (via drill hole & pull-through with button in sole of foot)
    • Fixed
    • Bony procedure required
    • May require MT osteotomies or Heyman-Herndon release
    • Best procedure is Cuboid Decancellation
    • Lateral incision & release of the C-C joint & reduction of it
    • Then remove wedge of bone from the middle of the cuboid
    • Other procedures to shorten the lateral column include
    • Dillwyn-Evans procedure
    • Shorten anterior process of calcaneus
    • Medial soft tissue release
    • Lichtblau osteotomy
    • Hindfoot Varus
    • Correction with calcaneal osteotomy
    • Oblique sliding osteotomy best
    • Slide the calcaneum laterally
    • Can also perform Dwyer
    • Lateral closing wedge calcaneal osteotomy
    • Salvage Procedure
    • Triple arthrodesis
    • Best option for failed or resistant clubfoot
    • Especially. if child > 12 years
    • Choices are
    • Standard triple arthrodesis
    • Lambranudi arhrodesis if fixed equinus
    • Plantargrade foot achieved with 95% good results but progressive Osteoarthritis (Ponsetti)
    • Talectomy
    • Reserved for the resistant arthrogrypotic club foot
    • Poor results
    • Complications
    • Neurovascular injury
    • Loss of foot (10% have atrophic dorsalis pedis artery bundle)
    • Undercorrection
    • Overcorrection (esp with Cincinatti)
    • Forefoot adductus
    • Hindfoot varus