Can a Morton's (Morton's metatarsalgia) neuroma be diagnosed with an X-ray?

From the Guidelines

X-rays are not reliable for diagnosing Morton's neuroma, as they cannot detect soft tissue abnormalities. Morton's neuroma is a thickening of tissue around a nerve between the metatarsal bones in the foot, and since it involves soft tissue rather than bone, it doesn't show up on X-ray images 1. For proper diagnosis of Morton's neuroma, physicians typically use ultrasound or MRI, which can visualize soft tissue structures. These imaging techniques can identify the enlarged nerve and surrounding inflammation characteristic of this condition.

According to the American College of Radiology, radiographs are insensitive to diagnose Morton’s neuroma but are useful to exclude other causes of webspace pain such as osteoarthritis, Freiberg’s infraction, and stress fractures 1. The most commonly used imaging techniques in the diagnosis of Morton’s neuroma are MRI and US, with MRI having a sensitivity of 87%, specificity of 100%, accuracy of 89%, PPV of 100%, and NPV of 60% in surgically treated patients 1. Ultrasound is also a reliable method to evaluate patients with Morton’s neuroma, with high sensitivities and specificities similar to MRI 1.

Key Points:

• X-rays are not reliable for diagnosing Morton's neuroma
• Ultrasound and MRI are the preferred imaging techniques for diagnosing Morton's neuroma
• Clinical examination is crucial for diagnosis, with symptoms such as burning pain, tingling, or numbness between the toes
• Treatment options include footwear modifications, orthotics, corticosteroid injections, or surgical intervention in persistent cases

Recommendations:

• Physicians should not rely on X-rays for diagnosing Morton's neuroma
• Patients with suspected Morton's neuroma should seek evaluation from a podiatrist or orthopedic specialist who can order appropriate imaging and recommend treatment options 1.

From the Research

Diagnosis of Morton's Neuroma

• Morton's neuroma is typically diagnosed based on characteristic symptoms and clinical findings, such as dull or sharp pain, numbness, and tingling in the affected area 2, 3, 4.
• Imaging modalities like ultrasound and magnetic resonance imaging (MRI) can be used to confirm the diagnosis, especially for differential diagnosis, exact localization, and number of neuromas 2, 4, 5, 6.
• Ultrasound is considered a highly accurate diagnostic tool for Morton's neuroma, with a sensitivity of 90% and specificity of 88% 6.
• MRI can also be used for diagnosis, but its accuracy is dependent on the size of the lesion, and it may not be as accurate as ultrasound for small lesions 5, 6.

Use of X-ray in Diagnosis

• There is no mention of X-ray being used as a diagnostic tool for Morton's neuroma in the provided studies 2, 3, 4, 5, 6.
• The studies suggest that ultrasound and MRI are the preferred imaging modalities for diagnosing Morton's neuroma, due to their ability to provide detailed images of the soft tissues and nerves in the foot 2, 4, 5, 6.

Limitations of Imaging Modalities

• Ultrasound is subject to interoperator variability due to differences in technique and level of experience 4.
• MRI and ultrasound may not be able to detect small lesions, which can still cause symptoms 5.
• Clinical assessment is considered the most sensitive and specific modality for diagnosing Morton's neuroma, and imaging modalities should be used to confirm the diagnosis rather than relying solely on them 5.