Abstract / Summary
Posterior tibial tendon rupture is rare in children and adolescents and may be overlooked following an ankle injury.Delayed diagnosis can result in persistent tendon dysfunction and progressive planovalgus deformity.A 13-year-old boy developed progressive planovalgus deformity following an eversion and external-rotation injury to the foot and ankle.Initial management included shoe modification; however, the deformity and functional impairment persisted.Clinical examination demonstrated loss of the medial longitudinal arch, impaired posterior tibial tendon function, and inability to perform a single-leg heel rise.MRI showed nonvisualization of the posterior tibial tendon at the ankle with tibialis posterior muscle atrophy, supporting chronic complete tendon rupture.Due to the chronic nature of the lesion and absence of usable tendon tissue for primary repair, reconstruction was performed using flexor hallucis longus tendon transfer, triple percutaneous tendo-Achilles lengthening, medial translation calcaneal osteotomy, and lateral column lengthening.At three years and nine months of follow-up, the patient was pain-free, had near-normal walking and activity levels, satisfactory heel alignment, near-normal restoration of the medial longitudinal arch, and was able to perform a single-leg heel rise.Chronic posterior tibial tendon rupture should be considered in adolescents who develop progressive flatfoot following an ankle injury, particularly when posterior tibial tendon function is impaired.MRI can assist in identifying chronic tendon disruption when the diagnosis is uncertain.In chronic cases where primary tendon repair is not feasible, tendon transfer combined with appropriate correction of the associated planovalgus deformity may provide satisfactory long-term functional outcomes.