From the Guidelines
Morton neuroma diagnosis should primarily rely on MRI due to its high sensitivity and specificity, with a sensitivity of 87%, specificity of 100%, accuracy of 89%, PPV of 100%, and NPV of 60% in surgically treated patients 1. When diagnosing Morton's neuroma, it is essential to consider the most effective imaging techniques. The two most commonly used techniques are MRI and US. However, MRI has been shown to have a significant impact on diagnostic and therapeutic decisions made by orthopedic surgeons, increasing their confidence levels and changing treatment plans 1. Some key points to consider when diagnosing Morton's neuroma include:
- MRI is a sensitive and reliable method to evaluate patients with metatarsalgia and Morton's neuroma 1
- The use of gadolinium may not be essential to detect Morton's neuromas but can facilitate its detection due to improved soft-tissue contrast 1
- Increased fluid within the intermetatarsal bursa, which suggests bursitis, is well demonstrated on MRI 1 Given the high sensitivity and specificity of MRI, it is the recommended imaging technique for diagnosing Morton's neuroma, allowing for accurate diagnosis and effective treatment planning 1.
From the Research
Definition and Causes of Morton Neuroma
- Morton's neuroma is a common pathology affecting the forefoot, characterized by fibrosis of the nerve, not a true neuroma 2.
- It is caused by pressure or repetitive irritation, leading to thickness of the digital nerve, typically located in the third or second intermetatarsal space 2.
Treatment Options
- Treatment options for Morton's neuroma include orthotics, steroid injections, and surgical excision, usually performed through a dorsal approach 2.
- Alcohol injection under sonographic guidance has also been shown to be effective, with a high success rate and minimal morbidity 3.
- A study on the effects of 4% ethanol sclerosing injection on Morton's neuroma found histologic changes, contrary to previous findings 4.
Efficacy and Long-term Results of Treatment
- A five-year follow-up study on alcohol injection for Morton's neuroma found that only 29% of patients remained symptom-free, with significant deterioration in symptoms over time 5.
- A systematic review of treatment options for Morton's neuroma found better outcomes with operative treatment, but highlighted the need for more randomized controlled trials to evaluate the risk-benefit ratio 6.
- The use of 4% ethanol sclerosing injection has been shown to have a high success rate, with up to 80% of patients experiencing relief from symptoms 4.