A mechanical comparison of first metatarsal diaphyseal osteotomies for the correction of hallux abducto valgus

The purpose of this study was to perform a mechanical comparison of four commonly performed diaphyseal first metatarsal osteotomies. Fifty first metatarsal-first cuneiform sawbone models were divided equally into five groups: control, offset V, inverted Z, Mau, and Ludloff osteotomy groups. All osteotomies were fixated with two 2.7-mm Synthes cortical screws. Each specimen was then stressed through a computer-controlled hydraulic tensile testing machine while recording the maximum load, energy, stiffness, and fracture pattern. The offset V was superior in terms of maximum load (137.8 N) and energy (0.86 J), as compared to the inverted Z (maximum load 74.7 N and energy 0.24 J), the Mau (maximum load 74.3 N and energy 0.15 J), and the Ludloff (maximum load 67.0 N and energy 0.32 J). The offset V (16.6 N/mm) demonstrated no significant difference in stiffness with the Mau (19.7 N/mm), and was stiffer to the inverted Z (14.4 N/mm) and the Ludloff (9.4 N/mm). We conclude that one could expect a safer and immediate return to weightbearing postoperatively with the offset V osteotomy as compared to the inverted Z, Mau, and Ludloff osteotomies.