Schematic representation of fracture zones for proximal fifth metatarsal fractures

Zone 1 (Z1): Tuberosity (red region) is the site for avulsion fractures. Fractures in Z1 are at low risk of complications due to robust blood supply.

Zone 2 (Z2): Includes proximal diaphysis (black region) and intermetatarsal zone (blue region). Fractures in this region may be acute or stress related (chronic). Tenuous blood supply to this region increases risk for delayed or nonunion.