Two cases of complete polymetatarsia without polydactyly.

We report two patients exhibiting complete polymetatarsia between the fourth and fifth metatarsals of the right foot, without supernumerary digit. To our knowledge, only a few cases of polymetatarsia without supernumerary digit have been reported, and all of those cases have involved incomplete duplication. Although there were no externally visible deformities in the present cases, plain radiographs revealed an extra bone between the fourth and fifth metatarsals. Case 1 presented with pain between the fourth and fifth metatarsals, and this pain ceased after resection of the extra metatarsal. Although case 2 was asymptomatic, the extra metatarsal of the left foot was resected during surgery for postaxial polydactyly of the right foot. Although differential diagnosis with os intermetatarseum was problematic, we concluded that the extra bones in the present cases were duplicated metatarsals, rather than accessory bones, based on three clinical findings: configuration of the extra metatarsal (articular cartilage and growth plate), in case 1; location of extra metatarsal (the most common site of polydactyly of the foot), in both cases; and polydactyly of the opposite foot, in case 2.