A Rare Morphological Variant of Postaxial Foot Polydactyly With an Accessory Articulating Osseous Structure of the Fifth Ray.

Postaxial polydactyly of the foot is a common form of digital duplication that often causes difficulty with footwear, metatarsalgia, and cosmetic concerns. Although it may present as an isolated anomaly, it can also be associated with genetic conditions. Surgical excision is the primary intervention, with generally excellent outcomes. A 5-year-old male presented with postaxial polydactyly of the left foot, characterized by an accessory articulating osseous structure associated with the fifth ray. The main complaints were difficulty with footwear and cosmetic appearance. Radiographic evaluation revealed a shortened, dysplastic fifth metatarsal associated with an accessory osseous structure that articulates with the duplicated lateral digits. The anatomical configuration did not completely correspond to existing classification systems. Surgical excision of the supernumerary digit and realignment of the metatarsal head were performed. At the 24-month follow-up, the patient demonstrated satisfactory radiographic healing, maintained toe alignment, painless full weight-bearing capacity, and an acceptable cosmetic appearance without postoperative complications. This case emphasizes the importance of detailed radiographic assessment and individualized surgical planning for rare anatomical variants of postaxial foot polydactyly that are not fully represented by current classification systems. Continued long-term follow-up is necessary to evaluate outcomes through skeletal growth.