Correction of metatarsus primus varus with the Chevron metatarsal osteotomy. An analysis of corrective factors.

A trigonometric evaluation of the amount of correction of metatarsus primus varus obtainable via lateral displacement of the first metatarsal head in a Chevron osteotomy technique revealed that approximately 1 degree of correction may be obtained for each millimeter of lateral shift. This calculated correction was correlated with the actual correction obtained in ten feet. Narrowing of the metatarsal head associated with removal of the medial eminence was an additional corrective factor.