Precise anatomic configuration changes in the first ray of the hallux valgus foot

To detect precise anatomical configuration of the first ray in feet with ha llux valgus, a two-dimensional coordinate system was devised for evaluation of a weight-bearing dorsoplantar radiograph. The radiographs, taken from 229 feet of 114 patients with symptomatic hallu x valgus and 94 normal feet, were investigated. A comparative study showed the first metatarsal head of a foot with hallux valgus was located on the m edial side of that of the normal foot and the base of the proximal phalanx of the hallux valgus foot was located on the same point of that of the norm al foot. Lateral translation of the base of the proximal phalanx occurred o nly in cases with overlap toes. Our study shows that subluxation of the met atarsophalangeal joint in hallux valgus is primarily caused by metatarsus p rimus varus, This study indicated that first metatarsal osteotomies should be given the first priority in consideration for bunion surgery, because th ese procedures could move the first metatarsal heads laterally in a more no rmal position.