Study Guide
Clubfoot
Key Points:
- The treatment of idiopathic clubfoot (IC) has changed in the past two decades with Ponseti serial casting currently the preferred method in North America.
- Although initial correction is achieved in almost 95% of IC by Ponseti method, a recurrence rate up to 50% is reported requiring further treatment. Compliance with the orthosis after the initial correction can decrease the recurrence rate
- The Ponseti method can result in favorable long term outcome in over 85%
- Comprehensive surgical soft tissue release can produce a plantigrade foot but these feet can be painful and stiff in adulthood.
Description:
The etiology of idiopathic clubfoot is not well understood, but thought to be multifactorial. Higher concordance of clubfeet in monozygotic twins than dizygotic twins, parent to child transmission as high as 20% in some families, the Carter effect, and effect of ethnicity on prevalence all suggest a genetic etiology.Epidemiology:
Idiopathic clubfoot is one the most common congenital deformities of the lower extremity. Its incidence is reported to be 1-2 cases per 1000 live births. The incidence is higher in Polynesians and lower in Chinese.Clinical Findings:
The major deformities of clubfeet include cavus, forefoot adductus, hindfoot varus and equinus. These deformities are the results of intraosseous (abnormal bone morphology) and interosseous (abnormal relationship of bones to each other) abnormalities. Intraosseous deformity is most pronounced in the talus with a short talar neck and medial and plantar deviation of the talar head. Interosseous deformity is seen as medial displacement of navicular and cuboid on the talar head and calcaneus, respectively.Diagnosis
Clubfoot diagnosis can be made prenatally via ultrasound as early as the second trimester, although studies show a false positive rate between 0-29 percent. Diagnosis is usually evident at birth with the heel in equinus and foot inverted on the tibia. In examination of clubfeet, neurological status of the feet should be carefully assessed. This can typically be done by plantar stimulation of the feet. Lack of dorsiflexion of the toes and resting position in plantar flexion, i.e. “The Drop Toe Sign,” has been reported and potentially indicates a neurological etiology of the clubfoot deformity.Classification
The degree of initial deformity is usually reported using the Pirani or Dimeglio classification. Both classifications have shown very good interobserver reliability after an initial learning curve (Flynn et al, 1998). Pirani classification assesses the severity by using a 6-point scoring system and 6 different physical exam findings. 3 points assess the midfoot deformity and 3 points assess the hindfoot deformity. Dimeglio classification uses a 20-point scoring system by assessing the residual deformity after applying gentle corrective maneuver. The severity of the deformity is then graded I-IV based on this scoring (Dimeglio et al,1995).Imaging Studies:
Radiographs typically show a decrease in the talocalcaneal angle in both the AP and lateral views and ankle equinus in the lateral view. If the diagnosis is clearly an isolated clubfoot, radiographs at the time of diagnosis are not commonly used. As treatment progresses, radiographs may be used to assess the relationship of the calcaneus and talus.Treatment:
Treatment of isolated clubfeet has significantly changed in the past two decades in North America with most treated successfully with serial Ponseti casting in addition to an Achilles tenotomy. Complete surgical release is reserved for those clubfeet that either cannot be corrected by non-operative means or rapidly recur.Ponseti Method
The Ponseti method is based on gradual correction of the deformity with serial weekly long leg casting. The deformities are corrected in order of the CAVE (Cavus, Adductus, Varus, and Equinus) pneumonic. Cavus is corrected first by elevating the first metatarsal and supinating the forefoot resulting in correction of the adductus deformity. Sequential casts then allow correction of the forefoot and calcaneus around the fixed talus. This is done by upward pressure on the first metatarsal (to prevent forefoot pronation) and downward pressure on talar head. Equinus is the last deformity to be corrected. Equinus is the hardest deformity to correct with casting and is treated with percutaneous Achilles tenotomy in most cases. After full correction of the deformity, patient is placed in foot abduction orthosis with external rotation full time for 3 months followed by part time wear for 2-4 years.The success of serial casting and tenotomy is reported to be approximately 95% for isolated clubfeet. The recurrence rate of the deformity is reported between 37-47% after initial correction (Richards et al, 2008). Discontinuation of brace wear is shown to strongly correlate with recurrence (Dobbs et al, 2004), and usually happens before the age of four years. Tibialis anterior tendon transfer (TATT) to the lateral aspect of the foot is shown to prevent recurrence in patients who present with “dynamic supination,” which indicates forefoot supination with ankle dorsiflexion in swing phase and weight bearing on the lateral side of the foot.
Cooper et al published their thirty year follow up of forty-five patients with seventy-one congenital clubfeet treated by Ponseti casting. Thirty-five (78 %) of forty-five patients treated by Ponseti casting reported excellent or good outcome (Cooper et al, 1995).
Video on POSNAcademy - Heel Cord Tenotomy
Tibilias Anterior Tendon Transfer
French Functional Method
This method involves daily manipulation of the newborn’s feet by a skilled physical therapist, followed by temporary immobilization with elastic or non-elastic adhesive taping. Richards et al. reported that this method was successful in 50.7% of the cases with mean follow up of 20 months (Richards, 2008). Rampal et al. reported average fourteen year follow up of 187 feet treated by this method. 85 of 187 feet (45.5%) required comprehensive soft tissue release to correct the remaining deformity. They reported very good or good results in 183 of 187 (98%) treated clubfeet and in eighty-one (95%) of eight-five operated feet (Rampal, 2013).Soft Tissue Release
Soft tissue release had been the main treatment for isolated clubfeet before the rise in popularity of the current non-operative methods in the last two decades. The procedure usually involves circumferential release of the subtalar joint and posterior capsule of the ankle joint with lengthening of the Achilles, flexor tendons, and posterior tibialis.Dobbs et al. studied the long-term outcome (average thirty-one years) of forty-five patients treated with soft tissue release. (Dobbs, 2006) Only twelve (26%) of forty-five patients reported good and excellent results with remaining thirty-three patients (73%) reporting fair/poor results.
Video on POSNAcademy - Posteromedial Release for club foot
Summary
Isolated clubfoot is a common anomaly that involves all the tissues below the knee. The initial treatment should be non-operative. Good to excellent long term outcomes can be expected with this treatment despite a slight amount of residual deformity. The feet treated with comprehensive surgical release may have good short term outcomes during but result in painful, stiff feet in adulthood.Complications:
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References:
- Cooper, D.M. and F.R. Dietz, Treatment of idiopathic clubfoot. A thirty-year follow-up note. J Bone Joint Surg Am, 1995. 77(10): p. 1477-89
- Dimeglio, A., et al., Classification of clubfoot. J Pediatr Orthop B, 1995. 4(2): p. 129-36.
- Dobbs, M.B., et al., Factors predictive of outcome after use of the Ponseti method for the treatment of idiopathic clubfeet. J Bone Joint Surg Am, 2004. 86-A(1): p. 22-7.
- Dobbs, M.B., R. Nunley, and P.L. Schoenecker, Long-term follow-up of patients with clubfeet treated with extensive soft-tissue release. J Bone Joint Surg Am, 2006. 88(5): p. 986-96
- Flynn, J.M., M. Donohoe, and W.G. Mackenzie, An independent assessment of two clubfoot-classification systems. J Pediatr Orthop, 1998. 18(3): p. 323-7
- Rampal, V., et al., Long-term results of treatment of congenital idiopathic clubfoot in 187 feet: outcome of the functional "French" method, if necessary completed by soft-tissue release. J Pediatr Orthop. 2013.33(1): p. 48-54
- Richards, B.S., et al., A comparison of two nonoperative methods of idiopathic clubfoot correction: the Ponseti method and the French functional (physiotherapy) method. J Bone Joint Surg Am, 2008. 90(11): p. 2313-21.