Rare presentation of foot postaxial polydactyly.

Polydactyly is a prevalent birth anomaly observed in the foot, and a number of classification systems have been suggested for this condition. Postaxial (fifth or little toe) polydactyly is the most common type. We encountered an exceedingly rare presentation of foot postaxial polydactyly that, to our inspection, had neither been previously classified nor described in published studies. In the present report, we have described an otherwise healthy 2-year-old female who had presented to our clinic with an isolated, extra little toe on her left foot. Foot radiographs revealed the presence of all 5 metatarsals; however, the fifth metatarsal was blocked and did not give rise to the fifth toe. Instead, the fifth (medial normal) and sixth (lateral extra) toes had originated from a single, separate accessory bud from the fourth metatarsal, and the main fourth metatarsal had given rise to the normal fourth toe. The lateral sixth toe was excised, and a periosteal sleeve of the excised extra toe was used for reconstruction of the lateral collateral ligament. We propose that this heretofore unmentioned presentation of postaxial polydactyly be added to the existing systems of classification of pedal polydactyly. A review of the published data pertaining to pedal polydactyly has also been presented.