Fractures of the Proximal Fifth Metatarsal: Selecting the Best Treatment Option.

Abstract

Because of circulatory differences in the three zones of the proximal fifth metatarsal, the location of a fracture must be considered when selecting treatment. The most proximal portion of the base of the fifth metatarsal has good blood supply. Fractures in this zone usually extend into the fifth metatarsocuboid joint. The second zone is associated with Sir Robert Jones, who in 1902 first asserted that fractures of the fifth metatarsal are commonly caused by indirect violence. Fractures in this zone take longer to heal than more proximal fractures, and treatment should be individualized. Whether to use a functional metatarsal brace, a stiff-soled shoe, a short-leg cast, or even internal fixation with a screw depends on the patient's lifestyle and desired activity level. Fractures in the third zone occur between the distalmost portion of the metaphysis and the proximal 1.5 cm of the diaphyseal tubular bone. This zone begins just distal to the ligamentous complex holding the proximal fourth and fifth metatarsals together. In active athletes, fractures in this zone often are stress injuries. For anatomic and mechanical reasons, such fractures are the most difficult to heal. Without surgical treatment, they may take 2 to 21 months to unite and are therefore more likely to need aggressive treatment.