Reversed Ponseti Procedure nach Dobbs zur Behandlung des kongentialen Talus verticalis

Abstract

Talus verticalis is a rare congenital foot deformity characterized by a rigid flatfoot with dorsal and lateral dislocation at the talocalcaneonavicular joint. The incidence is estimated at approximately 1 in 10,000 live births, with no significant gender ratio. Around half of the affected children have associated anomalies. The underlying etiology remains uncertain. Pathoanatomically, the navicular bone is displaced cranially and fails to articulate with the talar head, instead resting dorsally on the talar neck. The talus itself is vertically aligned, tilted caudally, and positioned medially relative to the calcaneus, which is rotated posterolaterally. A hypoplastic sustentaculum tali promotes talar displacement. The medial ligaments and tendons are elongated, creating a cavity that accommodates the dislocated talus, whereas the triceps surae and long toe extensors are shortened and contracted. The diagnosis is based on a clinical examination at birth. Characteristic findings include a convex plantar surface with a prominent talar head, an abducted and dorsiflexed forefoot, and an elevated heel with Achilles tendon shortening. On lateral X-rays, the talus appears vertically aligned, with its head often positioned lower than the calcaneus. The talocalcaneal angle is markedly increased. Stress X-rays in plantar flexion are essential to distinguish a vertical talus from flexible flatfoot or an oblique talus. Current treatment strategies are based on modifications of the Ponseti method, wich was originally developed for congenital clubfoot. In most cases, the Dobbs technique (''reverse Ponseti”) is applied, involving serial manipulations and casting. Once reduction of the talonavicular joint is achieved, it is fixed with a percutaneous K-wire. As in clubfoot treatment, an Achilles tendon tenotomy is frequently required to correct the equinus component. After approximately six weeks of cast immobilization, the K-wire is removed. In selected cases, open reduction of the talonavicular joint combined with tendon transfer procedures may be necessary. Postoperative care follows the principles of clubfoot management, including orthotic bracing to maintain correction. If conservative and minimally invasive measures fail, more extensive soft-tissue release procedures, tendon transfers, or corrective osteotomies remain an option. Congenital vertical talus is a rare but serious foot deformity that requires immediate recognition and treatment in the neonatal period. Early reduction of the talonavicular joint by casting and minimally invasive techniques has largely replaced extensive surgical interventions. Given its frequent association with syndromic and neurological conditions, a thorough evaluation is essential. With timely management and consistent orthotic follow-up, recurrence can usually be prevented.