Vascular anatomy of the metatarsal bones and the interosseous muscles of the foot.

Utilization of the metatarsal bones and interosseous muscles in foot reconstruction should be based on the vascular anatomy of the metatarsal bones and interosseous muscles. We studied the vascular anatomy of the metatarsal bones and the interosseous muscles to design a split metacarpal musculoosseous flap and dorsal interosseous muscle flap. Twenty-two feet from eleven cadavers that had been embalmed in formalin were studied. Dissection was done using a dissection microscope (x3.5), delineating meticulously the arcuate artery, dorsal metatarsal arteries and the small branches arising from the metatarsal arteries. The dorsal metatarsal arteries do not course at the midline of the interosseous muscles. The first dorsal metatarsal artery proceeds close to the first metatarsal bone in the first metatarsal space. While proceeding to the distal, it shoots out a branch that individually feeds the lateral head of the first dorsal metatarsal muscle and medial face of the second metatarsus, thereby feeding muscle and bone. Except for this branch, the first dorsal metatarsal gives off segmental and periosteal branches that individually feed the medial heads of the first dorsal metatarsal muscle and first metatarsal bone. The second, third and fourth metatarsal arteries proceed close to the third, fourth and fifth metatarsal bones in the metatarsal spaces. In these courses, the arteries give out segmental branches to both faces of the interosseous muscles and periosteal branches to the medial face of metatarsal bones. For defects or disease of the ankle bones, the metatarsal bones can be split at the medial border distally, and a split metatarsal musculoosseous flap, based proximally on the dorsal metatarsal artery, can be done. Distal intermetatarsal anastomoses between the dorsal and plantar vascular networks enables a split metatarsal musculoosseous flap based distally, including the dorsal metatarsal artery for bony defects of the proximal phalanx.