5th Metatarsal Base Fracture

The fifth metatarsal base can fracture in several ways, with the most common causes including trauma, repetitive stress, and twisting injuries. The primary mechanisms include:

• Direct trauma: A sudden impact, such as dropping a heavy object on the foot or a blunt force from a fall, can cause the bone to break.
• Twisting injuries: A common cause of fractures in the fifth metatarsal base is an ankle inversion injury—when the foot rolls inward suddenly, placing excessive stress on the bone. This type of injury is common in sports that require rapid directional changes, such as basketball, soccer, and football.
• Overuse or stress fractures: Repetitive activities, such as running or jumping, can lead to stress fractures over time. These small cracks in the bone develop due to prolonged pressure and insufficient recovery.
• Poor foot biomechanics: Individuals with high arches (pes cavus) or abnormal walking patterns may place excessive stress on the fifth metatarsal, making them more prone to fractures.
• Osteoporosis or weak bone structure: Conditions that reduce bone density can increase susceptibility to fractures, even with minimal trauma.

Patients with a fifth metatarsal base fracture may experience a variety of symptoms, which can range in severity depending on the type of fracture. The most common symptoms include:

• Pain and Tenderness: Patients typically feel pain along the outer edge of the foot, near the base of the fifth metatarsal. The pain is often worse with standing or walking.
• Swelling and Bruising: Swelling may develop around the fracture site, sometimes extending to the ankle or surrounding tissues. Bruising may be present if the fracture was caused by direct trauma.
• Difficulty Walking: Depending on the severity of the fracture, patients may experience pain with weight-bearing, limping, or an inability to walk normally.
• Deformity (in severe cases): In cases of significant displacement, the foot may appear misshapen or there may be an obvious bump at the site of the fracture.
• Pain with Foot Movement: Moving the foot, especially rotating it outward or attempting to push off, can aggravate the pain.

Diagnosing a fifth metatarsal base fracture requires a combination of clinical evaluation and imaging tests. A thorough assessment by an orthopedic specialist like Dr. Allison Boden ensures an accurate diagnosis and an appropriate treatment plan.

Physical Examination

• Dr. Boden will assess pain, swelling, and tenderness along the outer foot.
• She may apply pressure to the area to determine the location and severity of the pain.
• Ankle and foot movement will be tested to evaluate functional limitations.

Imaging Studies

• X-rays: A standard X-ray is the primary diagnostic tool used to confirm a fracture. Different views (anteroposterior, oblique, and lateral) help determine the fracture pattern and displacement.
• MRI: In cases where an X-ray does not clearly show a stress fracture, an MRI may be recommended to detect subtle injuries.
• CT scan: A CT scan may be used for more detailed imaging, particularly if the fracture involves multiple fragments or if surgical planning is necessary.

Differentiation from Other Conditions

• Soft tissue injuries: Some ankle sprains or ligament injuries can mimic the pain of a metatarsal fracture.
• Tendinitis or peroneal tendon injury: Inflammation of the peroneal tendons, which run along the outer foot, can sometimes present with similar pain.
• Arthritis or joint conditions: Patients with chronic foot pain may have an underlying joint issue rather than an acute fracture.