What are the diagnostic tests and treatment options for Morton's neuroma?

From the Guidelines

Morton's neuroma is best diagnosed with MRI, which has a sensitivity of 87%, specificity of 100%, and accuracy of 89%, making it a reliable method for evaluating patients with metatarsalgia and Morton's neuroma. The diagnosis of Morton's neuroma typically involves a combination of physical examination and imaging tests. The doctor will first perform a physical exam, pressing on the foot to locate pain and checking for a mass or click between the toes (Mulder's sign) 1.

Imaging Tests

Imaging studies include:

• Ultrasound, which can visualize the neuroma and rule out other conditions, with a pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 90%, 88%, 2.77, and 0.16, respectively 1
• MRI, which provides detailed images of soft tissues and is considered a reliable method to evaluate patients with Morton's neuroma, with a sensitivity of 87%, specificity of 100%, and accuracy of 89% 1
• X-rays may be ordered to exclude bone abnormalities

Treatment Options

Treatment begins with conservative approaches, including:

• Wearing wider shoes with lower heels
• Using metatarsal pads to reduce pressure
• Taking over-the-counter pain medications like ibuprofen or naproxen If these measures fail, corticosteroid injections, typically 40mg methylprednisolone with lidocaine, can reduce inflammation and pain, usually administered as a series of 1-3 injections spaced 4-6 weeks apart. For persistent cases, alcohol sclerosing injections may be used, typically as a series of 4-7 injections given at weekly intervals. Physical therapy focusing on foot strengthening and stretching can also help. When conservative treatments fail, surgical options include neurectomy (removal of the affected nerve segment) or nerve decompression, with a success rate of 80-85% but may result in permanent numbness in the affected toes and carries risks of infection, scarring, and recurrence.

From the Research

Diagnostic Tests for Morton's Neuroma

• Clinical tests such as thumb index finger squeeze, Mulder's click, and foot squeeze tests can be used to diagnose Morton's neuroma 2
• Imaging techniques like ultrasound and magnetic resonance imaging (MRI) can be used for confirmation, differential diagnosis, exact localization, and to determine the number of neuromas 2, 3
• Dynamic imaging during tests can be readily carried out with ultrasound 2

Treatment Options for Morton's Neuroma

• Conservative measures include footwear modifications, orthotics, and anti-inflammatory medication 4, 5
• Minimally invasive ultrasound-guided procedures can be employed as second-line treatments, including:
  • Infiltration of the area with corticosteroid and local anesthetic 4
  • Chemical neurolysis with alcohol or radiofrequency thermal neurolysis 4
  • Ultrasound-guided corticosteroid and local anesthetic injection (UG CS+LA) 6
• Surgical options include plantar incision neurectomy (PN) and dorsal incision neurectomy (DN) 6
• Treatment outcomes:
  • UG CS+LA probably reduces pain and increases function compared to non-ultrasound-guided CS+LA 6
  • CS+LA may result in little to no difference in pain, function, and health-related quality of life (HRQoL) compared to local anesthetic injection alone 6
  • PN may result in little to no difference in satisfaction and adverse events compared to DN 6