Clubfoot (Pediatric)

Synonyms
Talipes equinovarus

INTRODUCTION

Definition

Congenital structural foot deformity characterized by hindfoot equinus and varus as well as midfoot and forefoot adduction and cavus.

Epidemiology

  • Most common musculoskeletal birth defect. The overall incidence is 1:1000.
  • The highest prevalence is in Hawaiians and Maori.
  • More common in males (M:F=2-3:1).
  • The condition is bilateral in 50 % of cases. 
  • There is a 2.5-6.5 % risk for unaffected parents with an affected child of having another child with clubfoot.
  • There is a familial occurrence in 25 % of cases.

Etiology

The etiology is unknown. Majority of cases are idiopathic. The condition might be due to abnormal fibrosis, neurologic abnormalities, and arrested embryologic development.
  • Clubfoot is an isolated deformity in 80 % of cases.
  • There is an utero malalignment of the talocalcaneal, talonavicular and calcaneocuboid joints.
  • A link to PITX1 (transcription factor critical for limb development) has been found.

Pathogenesis

There are four basic deformities (CAVE) that are due to muscle contractures. The muscles and tendons of the gastrocnemius-soleus complex, the posterior tibialis, and the long toe flexors are shortened:
  • Cavus: Due to tight intrinsics, FHL and FDL. The cavus deformity is caused by the fact that the forefoot is pronated relative to the hindfoot, even though the entire foot appears supinated. 
  • Adduction of forefoot: Due to a tight tibialis posterior. Results in medial and plantar subluxation of the navicular bone on the talar head.
  • Varus of hindfoot: Due to tight Achilles tendon, tibialis posterior and tibialis anterior. The hindfoot is adducted and inverted under the talus.
  • Equinus: Due to tight Achilles tendon. 

Patoanatomy

Bony Changes found in clubfoot:
  • There is a talar neck deformity (medial and plantar deviation of the talar neck), with medial rotation of alcaneus and medial displacement of navicular and cuboid.
  • The calcaneus is in varus and rotated medially around talus.
  • The navicular and cuboid are displaced medially.

Classification

The Dimeglio-Bensahel and Catterall-Pirani classification systems are based on the severity of the clinical flindings and the correctability of the deformity.

CLINICAL FEATURES

Symptoms

Clubfoot is present after birth.

Signs

Inspection:
  • Small foot and small calf.
  • A slightly shortened tibia
  • Skin creases medially and posteriorly.
  • The foot deformities inlude: 
    • Hindfoot in equinus and varus (rigid equinus and resistance to passive correction).
    • Midfoot in cavus.
    • Forefoot in adduction.

Associated Conditions

Clubfoot is associated with:
  • Amniotic band syndrome (Streeter dysplasia).
  • Pierre Robin syndrome.
  • Opitz syndrome.
  • Larsen syndrome.
  • Prune-belly syndrome.
  • Anterior tibial artery hypoplasia or absence is common, regardless of etiology of clubfoot.
  • Arthrogryposis. 
  • Diastrophic dwarfism/dysplasia. 
  • Myelodysplasia. 
  • Tibial hemimelia. 

Differential Diagnosis

  • Myotonic muscular dystrophy.
  • Arthrogryposis multiplex congenita.
  • Myelomeningocele club foot.
  • Poliomyelitis.
  • Cerebral palsy.
  • Peroneal type of progressive muscle atrophy.

DIAGNOSIS

X-ray

General: X-ray is often not taken because diagnosis in infants is based on physical examination and there is minimal ossification of foot in the infant.
Projections: AP and lateral views of the foot.
  • Dorsiflexion lateral (Turco view):
    • The talocalcaneal angle will be less than normal (normally 35°). 
    • There is hindfoot parallelism between the talus and calcaneus (i.e. they are less convergent than in a typical foot).
    • In older children there might be a flat talar head.
  • AP (frontal):
    • Talocalcaneal (Kite) angle is less than normal (normally 20-40°).
    • The talus-first metatarsal angle will be negative (normally 0-20°). The talus points lateral to first metatarsal.
    • Also shows hindfoot parallelism (i.e. talus and calcaneus are less divergent than normal).
Findings: Overall, the talus and calcaneus are less divergent and more parallel (smaller talocalcaneal angle) than normal.

TREATMENT

Overview

Initial treatment is with Ponseti casting. Surgical treatment is indicated in patients that are refractory
to manipulations/casting, have syndrome-associated clubfoot, and there is a delayed presentation (children older than 1 to 2 years).

Treatment of Residual Clubfoot Deformity
Residual/Recurrent DeformityCorrective Surgery
SupinationTransfer of tibialis anterior tendon
VarusRevision posteromedial release or calcaneal osteotomy.
AdductusMedial column lengthening/lateral column shortening osteotomies
Internal rotation of footSupramalleolar tibial osteotomy
PlanovalgusCalcaneal neck lengthening or medial calcaneal slide
Severe multiplanar residual clubfoot deformityMultiplanar osteotomies of midfoot and/or hindfoot

Nonoperative Treatment

Ponseti casting:
  • Indication: First-line treatment in untreated clubfeet.
  • Method:
    • Serial weekly manipulation and casting using long-leg plaster casts. The sequence of deformity correction is cavus, adductus, varus, and equinus (CAVE):
      • Cavus: First cast corrects cavus by supinating the forefoot and dorsiflexing the first ray. 
      • Adductus: Corrected by lateral pressure on the distal talar head only, not the calcaneus.
      • Varus: Corrected by lateral pressure on the distal talar head only, not the calcaneus.
      • Equinus: Corrected by percutaneous Achilles lengthening at the end of casting.
    • Percutaneous Achilles tendon tenotomy/lengthening: Used to address hindfoot equinus is needed in at least 80-90% of children in most series. 
    • Foot abduction orthosis (FAO): Post-casting bracing with foot-abduction brace, such as the Denis Brown splint, is typically used 23 hours per day for 3 months, then used during naps and nighttime for 3 years (2-4 years).
  • Outcome: There is an 80-90 % success rate in avoiding comprehensive surgical release. The children can be expected to walk, run and be fully active.
  • Recurrence: Can be managed with repeated manipulation and casting followed by resumption of bracing.

Operative Treatment

Posteromedial soft tissue release and tendon lengthening:
  • Indication:
    • Resistant and/or recurrent clubfeet (5% of presenting idiopathic clubfeet) in young children which have failed Ponseti casting and bracing.
    • Rocker bottom feet that develop following serial casting which failed non-surgical intervention.
    • Syndrome-associated clubfoot if casting fails.
  • Method: Tendon lengthening, capsular release, and realignment. Often done at 9-10 months of age in children without syndromic feet so that walking is not delayed.
    • Posterior tibial artery must be carefully protected, because the dorsalis pedis artery is often insuffcient.
    • A medial opening or lateral column–shortening osteotomy or cuboidal decancellation is used to treat adductus in older patients (3-10 years of age). 
  • Postoperative care: Casting for several months is usually required.
  • Outcome: The procedure requires postoperative casting for optimal results. 
    • Long-term stiffness and pain are relatively common.
    • Extent of soft-tissue release correlates inversely with long-term function of the foot and patient.
Medial column lenthening or lateral column-shortening osteotomy, or cuboid decancellation:
  • Indication:
    • Often combined with initial surgical clubfoot release in children more than 2-3 years old.
    • May be performed in 3-10 years old children with recurrent deformity and “bean-shaped” foot.
Talectomy:
  • Indication: Used in salvage operations in rigid recurrent clubfoot in children with arthrogryposis (6-10 years old).
Ring fixator (Taylor Spatial Frame) application and gradual correction:
  • Indication: Complex deformity resistant to standard methods of treatment.
Multiplanar supramalleolar osteotomy
  • Indication: Rarely necessary.
    • This is a salvage procedure in older children with complex, rigid, multiplanar clubfoot deformities that have failed conventional operative management.
    • Also a salvage procedure in older children (8-10 years) with an insensate foot.
Triple arthrodesis:
  • Indication: Children presenting late. Though almost never indicated. 
  • Contraindication: Patients with insensate feet, because it causes rigidity of the foot, which may lead to ulceration.

COMPLICATIONS AND PROGNOSIS

Complications

Complications of nonoperative treatment
Recurrence or undercorrection:
  • Relapse in child < 2 years: Usually caused by noncompliance with FAO. It is associated with lower parental level of education.
    • Can be treated by repeating the manipulation and casting.
  • Relapse in child > 2 years:
    • Can be treated initially with manipulation and casting.
    • Consider tibialis anterior tendon transfer (split or whole tendon transfer).
    • If there is a recurrent equinus, consider repeating Achilles tendon lengthening/tenotomy or gastrocnemius recession.
Dynamic supination: Common deformity after clubfoot treatment. It occurs in up to 15-20 % of patients.
  • Causes: Overpull/overactivity of the anterior tibialis, with a weak peroneus longus. Also caused by undercorrection of forefoot supination.
  • Treatment: Can be treated with whole or split of tibialis anterior laterally. The results are comparable.
Rocker bottom deformity: Due to dorsiflexion of the hindfoot before varus is corrected.
Flat-top talus: Due to aggressive dorsiflexion causing flattening of talar dome.

Complications with surgical treatment
Residual cavus: Usually due to insufficient plantar release and/or placement of navicular in dorsally subluxed position.
Pes planus: Due to overcorrection, often from extensive subtalar capsular release. 
Intoeing gait: Results from internal tibial torsion and/or internal rotation of the talus within the ankle mortise.
Osteonecrosis of talus: Due to vascular insult to talus resulting in osteonecrosis and collapse.
Dorsal bunion
  • Causes: Dorsiflexion of the first metatarsal, caused by a strong/overpull of tibialis anterior and flexor hallucis brevis/abductor hallucis, secondary to weak plantar flexion. May be iatrogenic if peroneus longus is divided (inadvertent peroneus longus lengthening at the index procedure).
  • Treatment: Can be treated with capsulotomy, flexor hallucis longus lengthening, and transfer of the flexor hallucis brevis to become a metatarsophalangeal extensor. Other treatments include tibialis anterior lengthening or transfer, FHL transfer to the plantar aspect of the first MT head, and possible plantarflexion osteotomy of the first ray.
Other complications: Undercorrection.
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