Dorsal closing wedge metatarsal osteotomy: a trigonometric analysis.

Dorsal closing wedge osteotomies are commonly done in order to elevate and shorten the metatarsals in the management of severe metatarsalgia with callus formation. A trigonometric analysis reveals that a proximal closing wedge with a small (i.e., 2-mm) base will significantly elevate (approximately 1 cm), and slightly shorten a typical lesser metatarsal. Larger proximal wedge osteotomies in a lesser metatarsal would appear to have the potential for excessive elevation of the metatarsal head. Because of differences in metatarsal width and length, a proximal wedge in the first metatarsal will elevate the metatarsal head approximately twice the width of the wedge base. A distal closing wedge osteotomy will elevate a lesser metatarsal head approximately the width of the wedge base.