The Incidence of and Demographic Disparities Among Fifth Metatarsal Fracture Nonunions

Metatarsal fractures are one of the most common foot injuries seen in foot and ankle clinics, demonstrating an estimated annual incidence of 6.7/10,000 people and accounting for approximately 35% of all foot fractures. Approximately two-thirds of metatarsal fractures involve the Fifth metatarsal (5MT). In the general population, there is a peak incidence of 5MT fractures between the ages of 20 and 50, with a greater incidence in older females. A second peak incidence in a younger population is represented by athletes or military recruits, as a consequence of an acute injury or due to repetitive loading that results in stress fractures. ifth metatarsal fractures are traditionally classified according to the anatomic zone of the fracture. One of the most commonly utilized classification systems is the Lawrence-Botte, which categorizes 5MT fractures into three zones. Zone 1 involves the proximal aspect of the base of the 5MT, and fractures in this area are mostly tuberosity avulsion fractures. Zone 2 fractures, also known as Jones fractures, comprise the metaphyseal-diaphyseal junction. Lastly, zone 3 includes the most distal aspect of the base of the 5MT, occupying the diaphyseal region within 1.5 cm of the tuberosity. Stress fractures are more common in zone 3.