Diaphyseal nutrient foramina in the first metatarsals in normal and hallux valgus feet: location and surgical implications.

We examined 47 first metatarsals from amputated lower limbs to determine the situation of the main diaphyseal nutrient foramina (NFs) in normal and hallux valgus feet. All the NFs, excepting one, were in a plantar-fibular location. The NF situation was analyzed by means of the foraminal index and three minimum distances: from NF to proximal extremity, from NF to the shaft dorsal face (NFDS) and from NF to the border of the cartilaginous coating of the metatarsal head. We found a constant location of the NF in the middle of the total metatarsal length and sexual dimorphism in NFDS (lower in females); there were no differences by side, neither by digital or metatarsal types, nor between normal and hallux valgus types. Vascular complications in some osteotomies are discussed. In the surgical design, the NF situation can be estimated from either the total or physiological metatarsal length by means of the corresponding equations as reported here.