Clubfoot

Introduction

• Clubfoot is predominantly a hindfoot deformity caused by malalignment of the calcaneo-talo-navicular complex
• The components of deformity are
  • Plantar flexion of the 1st ray
  • Adduction of the forefoot / midfoot on the hindfoot
  • Varus and equinus of the hindfoot
  • The mnemonic CAVE (cavus, adductus, varus, equinus) is useful in remembering the components of this deformity

Pathogenesis

• Although numerous theories have been proposed, the aetiology is multifactorial and likely involves the effects of environmental factors in a genetically susceptible host
• There is abnormal tarsal morphology
  • Plantar and medial deviation of the head and neck of the talus
  • Abnormal relationships between the tarsal bones in all three planes
  • Contracture of the soft tissues on the plantar and medial aspects of the foot

Natural History

• Congenital clubfoot is seen in approximately 1/1,000 births
• The risk is approximately 1 in 4, when both a parent and one sibling have clubfeet
• It occurs more commonly in males (2 : 1)
• Bilateral in 50% of cases

Clinical Presentation

• Infant demonstrates
  • Forefoot cavus and adductus
  • Hindfoot varus and equines
• There is a range in the degree of flexibility
• All patients will exhibit calf atrophy
• Some cases have both internal tibial torsion and shortening of the ipsilateral extremity
• A complete physical examination should be performed to rule out coexisting musculoskeletal and neuromuscular problems
• The spine should be inspected for signs of occult dysraphism

Imaging and Diagnostic Studies

• Many clinicians reserve radiographs for older children with persistent or recurrent deformities
• AP and lateral radiographs are most commonly used to obtain radiographic measurements to describe the malalignment between the tarsal bones
• Most clinicians will hold the foot in the maximally corrected position
• A common radiographic finding is "parallelism" between lines drawn through the axis of the talus and the calcaneus on the lateral radiograph, indicating hindfoot varus

Treatment

• Immediate non operative treatment is recommended for all infants following birth
• These include techniques such as manipulation and casting (Ponseti method) or functional treatment (French method)

Ponseti method

• The Ponseti method involves a specific technique for manipulation and serial casting
• May be best described as minimally invasive rather than non operative
• The order of correction follows the mnemonic CAVE (described above)
• Weekly cast changes are performed
• Overall, 5-10 casts are typically required
• The most difficult deformity to correct is the hindfoot equinus
  • 90% of patients will require an outpatient percutaneous tenotomy of the heel cord 
  • A long leg cast with the foot in maximal abduction (70 degrees) and dorsi-flexion is worn for 3 weeks following tenotomy
• Then a bracing program begins
  • Full time brace for 3 months
  • Night-time brace for 3-5 years
• A subset of patients will require transfer of the tibialis anterior tendon to the middle cuneiform for recurrence
• Compliance with the splinting program is essential, as recurrence is common if the brace is not worn as recommended

French method

• Functional treatment or the "French method" is performed while the baby sleeps and involves
  • Daily manipulations
  • Splinting with elastic tape
  • Continuous passive motion (machine required)
• While the early results are promising, the method is labor intensive
• It remains unclear whether the technique will achieve greater popularity in the United States

Surgery

• Surgical realignment has a definite role in the management of clubfeet, especially in
  • Congenital clubfeet that have failed non operative or minimally invasive methods
  • Neuromuscular and syndromic clubfeet that are characteristically rigid
• In resistant cases, non operative methods such as the Ponseti technique may potentially be of value in decreasing the magnitude of surgery required
• Common surgical approaches include
  • Release of the involved joints (realign the tarsal bones)
  • Lengthening of the shortened posteromedial musculotendinous units
  • Pinning of the foot in the corrected position
• The specific procedure is tailored to the unique characteristics of each deformity
• Bony procedures (osteotomies), in addition to soft-tissue surgery, may be required for
  • Older children with untreated clubfeet
  • Recurrence
  • Residual deformity
• Triple arthrodesis is reserved as salvage for painful, deformed feet in adolescents and adults

Outcome

• The results of the Ponseti method are excellent at up to 40 year of follow-up
• The early results of functional method are promising