Figure 1. An oblique radiograph of the right foot taken at the time of injury.
Figure 2. An oblique radiograph taken at 6 weeks.
A 16-year-old high school basketball player presents to the office with a history of right foot pain. He initially injured his foot 2 months ago, which resulted in a zone 3 proximal fifth diaphyseal metatarsal fracture that was treated nonoperatively. An oblique radiograph was taken at the time of injury (Figure 1). The patient reports that the fracture was healing well after being treated in a walking boot and crutches (Figure 2). When he transitioned into a sneaker for walking at 6 weeks, the foot pain quickly returned.
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The patient was initially treated appropriately with a walking boot and crutches for a minimally displaced proximal fifth metatarsal fracture.1 This type of fracture generally heals within 6 to 8 weeks and patients should be pain free. Foot pain occurring beyond 2 months raises suspicion of a developing nonunion fracture.1
Fifth metatarsal fractures are a frequently encountered injury in primary care, accounting for 25% of metatarsal fractures.2 The mechanisms of injury are divided into 3 classes2:
- Zone 1: plantar flexion and hindfoot inversion; nonunion uncommon
- Zone 2: forefoot adduction; increased risk of nonunion (15%-30%)
- Zone 3: repetitive microtrauma, stress fracture in athletes; increased risk of nonunion
Computed tomography (CT) scan is the best imaging modality in the setting of delayed/nonunion healing that would be indicated by bridging callus. For patients whose fractures have not achieved osseous union after 3 months of conservative treatment, surgery is indicated and includes open autogenous bone grafting with percutaneous screw fixation.1,2
The use of a bone stimulator may help improve healing in patients showing signs of delayed union at 6 to 8 weeks. A bone stimulator is often used after surgery to improve healing rates. Magnetic resonance imaging is generally used to rule out fifth metatarsal stress fracture when radiographs are normal.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopaedics for Physician Assistants.
1. Lareau CR, Anderson RB. Jones fractures. Pathophysiology and treatment. JBJS Rev. 2015;3(7):01874474-201503070-00004. doi:10.2106/JBJS.RVW.N.00100
2. Steffes MJ, Weatherford B. 5th metatarsal base fracture. Accessed August 20, 2021. https://www.orthobullets.com/foot-and-ankle/7031/5th-metatarsal-base-fracture