Figure: Oblique radiograph of the foot shows a transverse avulsion fracture (arrow) of the 5th metatarsal bone with displacement and extension into the cuboid-metatarsal joint. Note a nearby 'os peroneum' (arrowhead).
Avulsion Fracture of Base of 5th Metatarsal
- Most common fracture at this location
- Usually extra-articular
- Due to sudden contraction of peroneus brevis muscle or lateral band of plantar fascia during inversion
- Treated conservatively, unless there is displacement or large fragment involving cuboid-metatarsal joint
- Other two types of fractures (at proximal 5th metatarsal) are Jones (AKA fracture at metadiaphyseal junction within 1.5 cm distal to tuberosity of 5th metatarsal), and stress fracture.
- Location (tip, tuberosity, metadiaphyseal junction, diaphysis)(to distinguish between different types of proximal 5th metatarsal fractures)
- Joint involvement (cuboid-metatarsal, 4th-5th intermetatarsal)
Nunley JA. Fractures of the base of the fifth metatarsal. Orthopedic Clinics of North America (January 2001)