07/04/2026
Fifth Metatarsal Fractures { Diagnosis ,Treatment }
Fractures of the fifth metatarsal are common following twisting injuries of the foot and ankle. They are categorized based on their anatomical location at the base of the bone, as the blood supply and healing potential vary significantly across these zones.
The Three Zones of the Fifth Metatarsal Base
Understanding the specific "Zone" is critical for determining the prognosis and risk of nonunion (failure to heal).
Zone 1 (Pseudo-Jones / Avulsion Fracture): The most common type. It occurs at the very tip (tuberosity) of the base, often caused by a forceful contraction of the peroneus brevis tendon during an inversion injury.
Zone 2 (True Jones Fracture): Occurs at the metaphyseal-diaphyseal junction. This area has a "watershed" blood supply, making it notorious for slow healing and a high rate of nonunion.
Zone 3 (Stess Fracture): Located in the proximal diaphysis (shaft). These are often chronic over-use injuries, frequently seen in patients with a cavus foot (high arch) which increases lateral foot pressure.
Clinical Presentation & Physical Exam
Patients typically present after an inversion sprain or a direct blow to the lateral foot.
Pain & Palpation: Localized tenderness directly over the bony prominence of the 5th metatarsal base.
Resisted Movement: Pain is often elicited during resisted eversion, as the peroneus brevis pulls directly on the fracture site.
Gait & Alignment: Look for a "peek-a-boo heel" (the heel is visible from the front), which indicates a varus/cavus foot alignment—a major risk factor for Jones stress fractures.
Imaging & Diagnostics
X-ray: Standard AP, lateral, and oblique views are usually sufficient. The AP view is the most helpful for identifying the fracture line at the base.
MRI/CT: MRI is superior for detecting early stress injuries before they appear on X-ray. CT is used to evaluate for nonunion (chronic failure to knit) in older injuries.
Treatment Strategies
The management of these fractures is often "hotly debated," particularly for Zone 2 (Jones) injuries.
Nonoperative: Most Zone 1 and some Zone 2 fractures are treated with 6–8 weeks of protected weight-bearing in a walking boot, postoperative shoe, or a short-leg cast.
Surgical (Internal Fixation): Usually reserved for elite athletes or cases of nonunion. The gold standard is an intramedullary screw inserted through the base to compress the fracture and allow for faster return to play.
Clinical Pearl
"In your clinic, never treat a 'Jones' fracture like a simple avulsion. Because Zone 2 has such poor blood supply, these patients need strict monitoring. If you see a patient with a high arch (cavus foot) and lateral foot pain, don't just treat the fracture—address the mechanics. Without a lateral wedge or orthotic to offload that 5th metatarsal, the fracture is highly likely to recur."