Treatment tactics for children with clubfoot in the absence of complete correction of the feet after using the Ponseti method

Introduction

It is now well established that the Ignacio Ponseti method is the gold standard for the treatment of clubfoot worldwide [1-3]. However, what should be done if, following the Ponseti maneuver, no peritalar reduction occurs in the subtalar and Chopart joints? What should be done if the orthopaedic surgeon examines a child who has previously undergone multiple surgeries, including soft tissue and sometimes bony procedures on the foot and lower leg? What should be done if the child initially presents at an age significantly older than recommended [4]? In recent years, the number of such children with clubfoot seen in the clinics of the city of Yaroslavl has been steadily increasing.

Objective

To highlight the relevance of the problem, demonstrate possible solutions, and present the capabilities of various surgical correction techniques for congenital clubfoot in children.

Literature Review

This review analyzes the outcomes of treating congenital and acquired clubfoot over the past 20 years. Historically, in the 2000s, clubfoot treatment in the department lasted 6–12 months and consisted of staged conservative correction according to Vilensky, followed by Zatsepin-Sturm release and casting for 5–6 months postoperatively, similar to the approach used by many authors at that time [5, 6]. Conservative treatment according to Vilensky meant that children with moderate and severe clubfoot invariably required surgical intervention. Children treated with this system were automatically assigned disability status until reaching adulthood. In 24.5% of cases, the feet remained in a neutral position, requiring neither custom orthopaedic footwear nor repeat surgeries. In 75.5% of cases, after treatment, children required ongoing courses of conservative management due to static-mechanical foot pain, and up to 30% required repeat surgery for relapse of the deformity during growth [7, 8].

Following the introduction of the Ponseti method into the routine practice of Russian paediatric orthopaedic surgeons, the number of extensive surgical procedures decreased dramatically. In our region, among children born and treated in a timely manner, clubfoot correction is achieved in 98% of cases, allowing the child to transition to brace wear for relapse prevention.

Since 2006, when the Ponseti method became routine, active treatment using this method, with timely diagnosis and presentation, rarely exceeds 9–10 weeks. A perinatal centre has been established in Yaroslavl, handling more than half of all births in the region (up to five thousand per year). All children diagnosed with clubfoot at the second screening (20 weeks of gestation) are referred to this perinatal centre, which is geographically adjacent to the only multidisciplinary regional children’s clinical hospital in the region. Immediately after birth, the patient with clubfoot is examined by an orthopaedic surgeon, who determines the treatment strategy and timing. Typically, full-term infants begin Ponseti casting at 3–4 weeks of age. Low-birth-weight infants start treatment after a full work-up and once their weight exceeds 4000 g. Children with syndromic conditions begin treatment after achieving weight gain, clinical stabilization, and screening ultrasound of internal organs.

Since 2006, this approach has dramatically reduced the number of extensive surgeries in children from the Yaroslavl region. Relapses following Ponseti treatment are usually managed with two- or three-stage repeat casting and anterior tibialis tendon transfer to the third cuneiform bone to normalize the muscle imbalance of the foot and lower leg [9, 10].

However, from 2008 to the present, referrals for clubfoot from other regions of Russia and CIS countries have resulted in a large group of patients with clubfoot (70–100 children per year) of various ages, from different clinics, with diverse prior treatment histories, including surgical interventions. For all children presenting with clubfoot, regardless of history, a minimum of three plaster casts based on the fundamental principles of I. Ponseti are initially applied. During casting, the authors performed weekly photographic documentation of foot abduction in dynamic progression. If good progress was observed (10–15 degrees of foot abduction per week), staged cast correction was continued. Ideally, upon completion of casting, children underwent surgery within the Ponseti technique framework (Achillotomy up to age three; after age three, Achillotomy or posterior release with anterior tibialis tendon transfer to the third cuneiform bone) [10, 11]. If the pace of correction was unsatisfactory to either the physicians or the family (I. Ponseti, in his book "Congenital Clubfoot: Fundamentals of Treatment," noted that surgery should be considered if casting exceeds 10 weeks), the authors proceeded to surgical treatment [11, 12].

In children with insufficient foot deformity correction, radiography, CT, and MRI were performed as indicated, and surgical indications were established. Following the examination, the authors divided the foot into three segments and corrected them sequentially, starting with the hindfoot, intraoperatively aiming for a neutral foot position, ranging from tenotomies and soft tissue releases to bony procedures (wedge osteotomies and arthrodesis techniques).

Materials and Methods

Surgical correction of the hindfoot. When, during casting, equinus was corrected to a neutral foot position, percutaneous achillotomy was indicated. At the end of treatment, clinical dorsiflexion should be 15 degrees or more. For deficient equinus correction in the hindfoot, a posterior release was performed, including Z‑lengthening of the Achilles tendon, capsulectomy of the talocrural and subtalar joints, and transection of the talofibular and calcaneofibular ligaments. If equinus correction was insufficient and an open physis was present, anterior distal hemiepiphysiodesis of the tibia was performed (Fig. 1).

Fig. 1. Patient S., 14 years old
A. Appearance: the patient with congenital clubfoot has previously undergone multiple surgeries for relapses. Posterior release was performed twice.
B. Radiography of the feet with maximum dorsiflexion: deformity of the ankle joint and flattening of the talar trochlea are noted.
C. Anterior distal hemiepiphysiodesis of the tibiae was performed.
D. Treatment result at 16 years of age: neutral position of the feet in the ankle joint has been achieved.

When growth plates were closed, a closing wedge supramalleolar osteotomy with plate or Kirschner wire fixation was performed to correct equinus. Simultaneously with osteotomy, derotation of the tibia may be performed in cases of torsional dysfunction of the lower extremity with the apex of the deformity at the tibial level.

The second aspect of hindfoot correction, when insufficient divergence of the talus and calcaneus is present, is hindfoot varus. The normal hindfoot alignment is defined as a valgus angle of 0–6 degrees; an axial deviation of more than 0 degrees inward results in varus deformity. When varus of more than 10 degrees persisted after the casting course in children over 5 years of age, the authors performed a closing wedge osteotomy of the calcaneus. In cases of bilateral deformity, or alternatively, the calcaneal tuberosity was displaced via a vertical osteotomy proximal to the physis, with lateralization of up to 5–7 mm (Fig. 2).

Fig. 2. Patient S., 7 years old
A. Axial radiography of the hindfoot of both feet: pathological varus of the hindfoot of both feet is revealed.
B. Osteotomy of the calcaneal tuberosity with its lateralization is performed.
C. Axial radiography of the hindfoot of both feet, confirming good postoperative correction.

Surgical correction of the midfoot. Under general anaesthesia, the foot was assessed in the maximally corrected position. Up to three years of age, foot position was evaluated by lateral radiography in maximum dorsiflexion; after three years, weight-bearing anteroposterior and lateral radiographs were performed. In the presence of persistent talonavicular subluxation and palpation of the lateral hemisphere of the talar head, a medial approach to the foot was made, followed by medial release aimed at lengthening the posterior tibial tendon and capsulectomy of the talonavicular joint medially, dorsally, and plantarly. Sometimes, when treating atypical clubfoot, the authors did not observe complete cavus correction. To correct this, a plantar release was performed, including detachment of the entire soft tissue plantar complex attached to the plantar tuberosities of the calcaneus. When forefoot adduction with the apex of the deformity at the midfoot level was present, a closing wedge osteotomy of the cuboid bone and an opening wedge osteotomy of the medial cuneiform bone were performed simultaneously with anterior tibialis tendon transfer, followed by Kirschner wire fixation in the corrected position (Fig. 3).

Fig. 3. Forefoot adduction with the apex of the deformity at the midfoot level
A. External view of the foot on the operating table from the side of the sole.
B. Preoperative X-ray.
C. Schematic of surgical treatment.
D. Clinical result before removal of the pins.
E. Anteroposterior radiograph of the feet 8 weeks after surgery.

Surgical correction of the forefoot. When forefoot adduction correction was lacking, the authors performed osteotomy of the metatarsal bases. Over the last five years, this procedure has been performed minimally invasively using a burr through three dorsal foot punctures. This approach avoided traumatic skeletonization of the metatarsal bases. In the presence of cavus deformity with the apex at the Lisfranc joint level after physeal closure, arthrodesis of this joint with screw fixation was performed.

Sometimes the foot deformity did not allow isolated correction of each segment separately; in such cases, a triple arthrodesis was performed, correcting all segments through joint resection and fixation with metal implants (screws and wires). Toe deformities secondary to tendon shortening were corrected simultaneously with the rest of the foot, using temporary transarticular Kirschner wire fixation, percutaneous tenotomies of the flexor and extensor tendons, and capsulectomies. Arthrodesis of the proximal interphalangeal joint was performed when indicated (Fig. 4).

Fig. 4. A 17-year-old female patient with neurogenic cavo-equinovarus deformities of both feet
A. Appearance before surgery.
B. Radiography before surgery.
C. Radiographs after surgery: triple arthrodesis with combined fixation using screws and pins was performed.
D. Appearance of the feet 3 weeks after triple arthrodesis and percutaneous tenotomy of the deep flexor tendons of the second to fifth toes of both feet.

Results

The Ponseti approach for children with clubfoot, regardless of the severity of the foot deformity and prior treatment options, enables complete correction in up to 98% of cases with timely presentation and adherence to its basic principles. In cases where complete correction is not achieved, the Ponseti method reduces the extent of subsequent surgical correction. Furthermore, children who undergo a course of preoperative casting tolerate postoperative stress more easily psychologically. Surgical treatment performed after preliminary casting is less aggressive, as reflected by a smaller volume of tissue transected (Table 1A, 1B).

Table 1. Foot releases in children with clubfoot before and after the introduction of the I. Ponseti technique
A. Change in the extent of medial release before and after casting

B. Change in the extent of plantar release before and after casting

Discussion

Currently, the majority of orthopaedic surgeons in Russia regard the Ponseti method as the standard of care and use it when a patient first presents with clubfoot. However, because not all orthopaedic surgeons apply this technique, the Ponseti method yields varying results "in different hands." Following the opening of perinatal centres across the country, a large group of children from the premature infant population with extremely low birth weight has emerged. In addition to congenital limb anomalies, these children often present with neurological deficits. The aforementioned groups of children require a thoughtful approach from the orthopaedic surgeon, but Ponseti casting remains the starting point of their treatment. Complete correction is not always achievable in these patients, but the approach described above has enabled a reduction in surgical extent. It should also be noted that Ponseti treatment is outpatient care, while surgical re‑correction of deformities can only be performed in an inpatient setting. Many hospital-based physicians do not see outpatients or manage ambulatory patients, and children in this category require a unified approach across both the outpatient and inpatient phases of treatment. In the Yaroslavl region, children with clubfoot are treated by a single team of physicians who perform both outpatient casting and the inpatient phase of surgical correction. The Ponseti approach to clubfoot entails simultaneous manual correction of all foot segments in a single motion. When the Ponseti method fails, the foot is divided into three segments, and each segment is corrected during a single surgery, but separately. Surgical intervention begins with the hindfoot, followed by the midfoot and finally the forefoot. A different sequence may result in overcorrection of the deformity at the end of the procedure.

Conclusion

By adopting the contemporary approach to treating clubfoot in children using the Ponseti method as a starting point, with timely initial presentation, we were able to correct foot deformity in up to 98% of cases, regardless of severity or association with other syndromes. Furthermore, using Ponseti casting at the beginning of treatment in children with relapses or incomplete correction simplifies subsequent surgical intervention by reducing the amount of tissue transected, as the primary goal is to achieve a neutral foot position with minimal surgical trauma and preservation of maximal lower limb function.