Surgical Reconstruction Technique of Two Patients With Tarsal Type Preaxial Polydactyly: Two True Prehalluces

Polydactyly of the foot occurs in 1.7 cases per 1000 live births, comprising 45% of congenital abnormalities of the foot. Most reported cases of polydactyly of the foot are postaxial, and 15% are preaxial; of those, tarsal type preaxial polydactyly (a true prehallux) occurs in only 3% of cases. Because of this rarity, there is minimal literature available to guide management or surgical reconstruction. Two newborns presented with similar tarsal type preaxial polydactylies in the context of multiple congenital anomalies at a single institution. Patient 1 presented at birth with an accessory digit arising medially from the right foot at the medial malleolus. Two weeks later, genetically unrelated, patient 2 presented at birth with an accessory digit arising medially from the right foot at the talus. Both patients underwent resection of the extra digit and reconstruction including transfer of the accessory anterior tibial tendon arising from the preaxial extra digit to the remaining first ray. Two years after surgery, both patients are walking well with preserved dorsiflexion strength. Given the rarity of true prehallux cases, reported surgical treatment and outcomes are lacking. This case demonstrates the management of 2 patients to better guide future patient care. Although nonsurgical treatment with shoewear modification is an option, surgical reconstruction facilitated wearing typical shoes while preserving ambulatory ability. Both patients in this series had an accessory anterior tibial tendon. Surgical transfer of the tendon prevented loss of dorsiflexion strength and foot drop postoperatively.