Introduction
  • Idiopathic deformity of the foot of unclear etiology
  • Epidemiology
    • demographics
      • most common musculoskeletal birth defect
      • overall incidence 1:1,000, though some populations 1:250 
      • highest prevalence in Hawaiians and Maoris
      • male:female ratio approximately 2:1
    • location
      • half of cases are bilateral
    • In 80%, clubfoot is an isolated deformity
  • Pathophysiology
    • muscle contractures contribute to the characteristic deformity that includes (CAVE)     
      • Cavus (tight intrinsics, FHL, FDL)
      • Adductus of forefoot (tight tibialis posterior)
      • Varus (tight tendoachilles, tibialis posterior, tibialis anterior)
      • Equinus (tight tendoachilles)
    • bony deformity consists of medial spin of the midfoot and forefoot relative to the hindfoot
      • talar neck is medially and plantarly deviated
      • calcaneus is in varus and rotated medially around talus
      • navicular and cuboid are displaced medially
    • table of foot deformity muscle imbalances 
  • Genetics
    • genetic component is strongly suggested
    • unaffected parents with affected child have 2.5% - 6.5% chance of having another child with a clubfoot
    • familial occurrence in 25%
    • recent link to PITX1, transcription factor critical for limb development
    • common genetic pathway may exist with congenital vertical talus  
  • Associated conditions
    • arthrogryposis  
    • diastrophic dysplasia  
    • myelodysplasia  
    • tibial hemimelia 
    • amniotic band syndrome (Streeter dysplasia)
      • upper extremity and hand anomalies common in this population 
    • Pierre Robin syndrome
    • Opitz syndrome
    • Larsen syndrome
    • prune-belly syndrome
    • anterior tibial artery hypoplasia or absence is common, regardless of etiology of clubfoot
Anatomy
  • Muscle contractures contribute to the characteristic deformity that includes (CAVE)     
    • Cavus (tight intrinsics, FHL, FDL)
    • Adductus of forefoot (tight tibialis posterior)
    • Varus (tight tendoachilles, tibialis posterior, tibialis anterior)
    • Equinus (tight tendoachilles)
  • Bony deformity consists of medial spin of the midfoot and forefoot relative to the hindfoot
    • talar neck is medially and plantarly deviated
    • calcaneus is in varus and rotated medially around talus
    • navicular and cuboid are displaced medially
  • Table of foot deformity muscle imbalances 
Presentation
  • Physical exam
    • inspection
      • small foot and calf 
      • shortened tibia
      • medial and posterior foot skin creases
      • foot deformities
        • hindfoot in equinus and varus
          • differentiated from more common positional foot deformities by rigid equinus and resistance to passive correction
        • midfoot in cavus
        • forefoot in adduction
Imaging
  • Radiographs
    • often not taken
    • recommended views, if taken
      • dorsiflexion lateral (Turco view)
        • shows hindfoot parallelism between the talus and calcaneus (i.e. they are less convergent than in a typical foot) 
        • will see talocalcaneal angle < 25° 
        • may see flat talar head in older children, but not in infants
      • AP
        • talocalcaneal (Kite) angle is < 20° (normal is 20-40°) 
        • talus-first metatarsal angle is negative (normal is 0-20°) -- talus points lateral to first metatarsl
        • also shows hindfoot parallelism (i.e. talus and calcaneus are less divergent than normal)
  • Ultrasound 
    • clubfoot sometimes diagnosed in utero
      • 1st trimester
        • associated anomalies, including non-musculoskeletal ones, are very common in children diagnosed with clubfoot in the first trimester
      • 2nd trimester
        • these are typically true clubfeet, but associated anomalies are less common
      • 3rd trimester
        • if clubfoot first diagnosed in 3rd trimester, the false positive rate is higher due to higher probability of intrauterine crowding 
Treatment
  • Nonoperative
    • Ponseti method of serial manipulation and casting    
      • Ponseti method is the gold standard in most of the world
      • indications
        • this is the standard of care for untreated clubfeet  
      • outcomes
        • Ponseti method has a > 90% success rate in avoding comprehensive surgical release
        • children can be expected to walk, run and be fully active in the absence of other comorbidities 
    • French method of daily physical therapy, manipulation and splinting
      • indications
        • rarely used in the United States
      • outcomes 
        • good outcomes in skilled hands
  • Operative 
    • posteromedial soft tissue release and tendon lengthening
      • indications
        • resistant and/or recurrent feet 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
        • when performed, it is often done at 9-10 months of age in non-syndromic feet so walking is not delayed 
      • outcomes
        • 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
      • indications
        • 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
      • indications
        • in severe, rigid recurrent clubfoot in children with arthrogryposis
        • age typically 6-10 years
    • multiplanar supramalleolar osteotomy 
      • indications
        • rarely necessary
        • salvage procedure in older children with complex, rigid, multiplanar clubfoot deformities that have failed conventional operative management
        • salvage procedure in older children (8-10 yrs) with an insensate foot
    • ring fixator (Taylor Spatial Frame) application and gradual correction
      • indications
        • complex deformity resistant to standard methods of treatment
        • recurrence of deformity is very high after frame removal
    • triple arthrodesis
      • indications
        • almost never indicated
        • contraindicated in insensate feet due to rigidity and resultant ulceration
Techniques
  • Ponseti method of serial manipulation and casting  
    • goal is to rotate foot laterally around a fixed talus
    • order of correction (CAVE)
      1. Cavus
      2. Adductus
      3. Varus
      4. Equinus
    • Heel cord tenotomy needed in at least 80-90% of children in most series
    • Foot abduction orthosis (FAO) 
      • critical for long-term success
      • FAO noncompliance is the biggest risk factor for deformity recurrence
      • FAO use is ~ full-time for 3 months and then at night (+/- naps) for 2-4 years
Ponseti Method
Month 1-4 Weekly serial casting (with knee in 90° of flexion ) with forefoot supination, then forefoot abduction

• First correct cavus with forefoot SUPINATED (NOT pronated) by aligning the less varus forefoot with the more varus hindfoot (pronation would increase cavus deformity) 
• Secondly correct adduction and heel varus by rotating calcaneus and forefoot around talus (head of talus acts as a fulcrum) into forefoot ABDUCTION
Tendoachilles lengthening (TAL) at week 8 required in > 80-90%

• Equinus correction last with tendinoachilles tenotomy 
• Perform when foot is at least 60° abducted, heel is in valgus and equinus persists   
• Cast in maximal dorsiflexion for 3 weeks after tenotomy
Month 4-8 Foot abduction orthosis (FAO) 
• 23 hours a day for 3 months after correction 
• night time/nap time only until age 4 years

• With FAO holding affected feet at least 60°external rotation and 30° in normal foot for unilateral cases 

• Feet are measured prior to tenotomy so FAO is available on the day of post-tenotomy cast removal
2-4 years Tibialis anterior tendon transfer (TA transfer) q at 2-5 yrs of age (30-50% will require)

• 30-50% will need TA transfer with or without repeat TAL or gastrocnemius recession for recurrent deformity
• Indicated if the patient demonstrates supination during gait

 
  • French method of daily physical therapy, manipulation and splinting
French Method
Correction Phase

• Daily corrective manipulations of the clubfoot are performed by an experienced physical therapist and the correction is held with elastic taping  and splints until the next day's session. 

• Family participation is integral to the success of this treatment program as the family must be able to bring the infant to therapy during the week for 1-3 months

• Each session lasts approximately 30 mins per foot and manipulations are performed in a progressive gentle pattern

• Begin with derotation of the calcaneopedal block and correction of forefoot adduction through massage of the Achilles tendon and gastrocnemius muscle 

• Next, medial soft tissues are stretched to allow the navicular to move away from the medial malleolus and its medial position on the head of the talus . Distraction of the forefoot and midfoot helps to loosen the tightened structures, and derotation of the foot facilitates reduction of the talus  

• To maintain the gain achieved in passive range of motion, the toe extensors and peroneals are recruited by stimulating (tickling) the lateral border of the foot and leg and the tops of the toes

• Once the talonavicular joint has been reduced, attention is directed toward the correction of varus and equinus. With the valgus maneuver, the calcaneus gradually moves to a neutral and eventually valgus position . The ankle is externally rotated at the same time that the calcaneus is being mobilized into valgus. The knee should be kept at 90° during these maneuvers

• Equinus is corrected with gradual dorsiflexion of the foot. Correction of equinus can be augmented with a percutaneous heel cord tenotomy

Maintenance Phase

• Fewer visits to the therapist are needed as the parents assume the daily treatment exercises and taping

• Periodic follow-up is needed to monitor the range of motion of the foot and the development of the infant and to fabricate new splints

• Once the patient is walking, taping is discontinued and a resting ankle-foot orthosis is used during nighttime and naps until the age of two years.

• Throughout this treatment program, the patient visits the physician every two to three months for evaluation of the foot

 
Complications
  •  Complications with nonoperative treatment
    • deformity relapse
      • relapse in child < 2 years
        • early relapse usually the result of noncompliance with FAO
        • treat with repeat manipulation and casting
      • relapse in child > 2 years
        • treat initially with casting
        • consider tibialis anterior tendon transfer (split or whole tendon transfer)
        • consider repeat Achilles tendon lengthening or gastrocnemius recession for recurrent equinus
    • dynamic supination
      • treat with whole or split anterior tibial tendon transfer (results are comparable, but whole tendon transfer was preferred in OITE question over split anterior tibial tendon transfer)    
  • Complications with surgical treatment 
    • residual cavus
      • result of insufficient plantar release and/or placement of navicular in dorsally subluxed position q
    • pes planus
      • results from overcorrection, often from extensive subtalar capsular release
    • undercorrection
    • intoeing gait
      • commonly due to internal tibial torsion and/or internal rotation of the talus within the ankle mortise
    • osteonecrosis of talus
      • results from vascular insult to talus resulting in osteonecrosis and collapse
    • dorsal bunion    
      • caused by dorsiflexed first metatarsal (FHB and abductor hallucis overpull secondary to weak plantar flexion) and overactivity of anterior tibialis
      • may be associated with inadvertent peroneus longus lengthening at the index procedure
      • treat with tibialis anterior lengthening or transfer, FHL transfer to the plantar aspect of the first MT head, and possible plantarflexion osteotomy of the first ray