The stability of fixation of first metatarsal osteotomies

Five different types of osteotomies for the correction of the hallux valgus deformity were performed on dried human first metatarsal bones. These included the step-cut Mitchell osteotomy, a distal transverse osteotomy, a distal biplanar osteotomy, the Chevron osteotomy, and a basilar osteotomy. Each type of procedure was then fixed using a variety of clinically appropriate techniques including single K-wires, crossed K-wires, a single A-0 cancellous screw, a single A-0 cortical screw, and three different types of sutures. Specimens were placed in a test jig and physiological loads applied with a Materials Testing Systems servohydraulic testing machine (Minneapolis, Minnesota). No difference in stability was observed between the various types of osteotomies, except for the Chevron osteotomy, which did possess greater inherent stability. Fixation by screws or multiple K-wires provided the most stable configuration when compared to other methods. The postoperative regimen following first metatarsal osteotomy should take into account the relative stability of fixation. Cast immobilization and a nonweight-bearing status may be preferable after procedures characterized by less mechanical stability.