Rigid flat foot - Tarsal coalition (arabic version)

we will talk today about rigid flat foot. Definition of rigid flat foot: Abnormal connection between the between the anterior process of the calcaneus and the most lateral aspect of the navicular Talocalcaneal coalitions occur within the subtalar joint, most commonly involving the middle facet. Could be fibrous coalition (syndesmosis) or cartilagenous coalition (synchondrosis) or osseous coalition (synostosis) PATHOGENESIS of rigid flat foot: Failure of segmentation. Symptoms typically develop in later childhood, usually between 8 and 12 years old for all CN coalitions and 12-16 in TC Delayed onset of symptoms, till the coalition ossifies over time, making it more rigid and more likely to limit subtalar motion. Pathoanatomy : Flattening of longitudinal arch Abduction of forefoot Valgus hindfoot Peroneal spasticity (also known as peroneal spastic flatfoot) PATIENT HISTORY AND PHYSICALFINDINGS: USUAL SYSTEM history of prior recurrent ankle sprains 75% of people are asymptomatic location of pain sinus tarsi and inferior fibula suggests calcaneonavicular distal to medial malleolus or medial foot suggests talocalcaneal pain worsened by activity: onset of symptoms correlates with age of ossification of coalition difficulty walking on uneven surfaces Pain generator: Ossification of previously fibrous or cartilaginous coalition Microfracture at coalition bone interface Secondary chondral damage or degenerative changes Foot is only flat with standing and reconstitutes with toe walking, hallux dorsiflexion = (jack test). Hindfoot valgus corrects to a varus position with toe standing evaluate for decreased dorsiflexion and tight heel cord (u have to supinate forefoot to lock Chopart joint) Achilles contracture. The examiner holds the calcaneus in a neutral position and notes dorsiflexion of the ankle with the knee both flexed and extended (the Silfverskiold test). The result is measured in degrees of ankle dorsiflexion. A significant Achilles contracture limits the degree of correction possible with bracing and may require surgical correction. Imaging : Oblique AP C-sign C-shaped arc formed by the medial outline of the talar dome and posteroinferior aspect of the sustentaculum tali "anteater" sign Elongated anterior process of calcaneonavicular coalition CT scan: 3 D MRI: may be helpful to visualize a fibrous or cartilaginous coalition Treatment Immobilization with casting, analgesics: initial treatment for symptomatic cases Operative Coalition resection with interposition graft, +/- correction of associated foot deformity (2nd session ) Indications: persistent symptoms despite prolonged period of nonoperative management coalition involves 50% of joint surface area Interposition material: Interposed fat graft (buttock) Bone wax Extensor digitorum brevis (calcaneonavicular coalition) Split flexor hallucis longus tendon (talocalcaneal coalition) Subtalar arthrodesis consider if coalition involves 50 % of the joint surface of a talocalcaneal coalition triple arthrodesis (subtalar, calcaneocuboid, and talonavicular) advanced coalitions that fail resection Diffuse associated degenerative changes affecting calcaneocuboid and talonavicular joints Calcaneonavicular coalition resection oblique incision just distal to subtalar joint between extensor tendons and peroneal tendons TC coalition resection : medial approach to hindfoot horizontal or curved incision centered over sustentaculum tali between flexor digitorum longus and neurovascular bundle Thanks