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%

C>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

P>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)

Pa>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

Clini>Clinical Features

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  • 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

    • RadiologyRadiology

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  • 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

      Treatmentlist">
    • 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