From the Guidelines
A 20mm Morton's neuroma requires prompt evaluation and treatment, starting with conservative measures, and potentially progressing to corticosteroid injections or surgical intervention if symptoms persist. This size is considered quite large for a Morton's neuroma, which typically measures 5-15mm 1. The diagnosis of Morton's neuroma can be confirmed using MRI, which has a sensitivity of 87%, specificity of 100%, accuracy of 89%, PPV of 100%, and NPV of 60% in surgically treated patients 1.
Treatment options for a 20mm Morton's neuroma include:
- Conservative measures such as wearing wider shoes with a lower heel and good arch support
- Using metatarsal pads to spread the bones and reduce pressure on the nerve
- Taking over-the-counter anti-inflammatory medications like ibuprofen (400-800mg three times daily with food) or naproxen (220-440mg twice daily with food) for pain relief
- Physical therapy focusing on foot strengthening and stretching If conservative measures fail after 4-6 weeks, consider corticosteroid injections administered by a podiatrist or orthopedic specialist. Given the large size, surgical intervention might ultimately be necessary, which typically involves either removing the neuroma or releasing the ligament that compresses the nerve 1.
It is essential to note that the large size of the neuroma suggests it has likely been present for some time and may be causing significant pain, numbness, or burning sensations when walking, particularly when wearing narrow shoes. MRI can help evaluate the extent of the neuroma and guide treatment decisions 1. Surgical intervention may be necessary to alleviate symptoms and improve quality of life, especially if conservative measures fail.
From the Research
Definition and Treatment of Morton's Neuroma
- Morton's neuroma is a common pathology affecting the forefoot, characterized by fibrosis of the nerve, typically located in the third or second intermetatarsal space 2.
- The treatment options for Morton's neuroma include orthotics, steroid injections, and surgical excision, usually performed through a dorsal approach 2.
Size and Treatment Outcomes
- A study on the treatment of Morton's neuroma found that operative treatment showed better outcomes, with case series and few randomized controlled trials showing better results with invasive treatment 3.
- For neuromas larger than 5-6 mm, orthotics and/or shoe modifications do not seem to give convincing results, proving to be more a palliation for the clinical condition to allow an acceptable life with pain rather than a real treatment 4.
- A 20mm Morton's neuroma would likely require surgical excision, as conservative treatments such as orthotics and shoe modifications are less effective for larger neuromas 4.
Surgical Techniques
- Simple excision of the neuroma with proximal burial into muscle or bone is a common surgical technique, but inadequate resection of the nerve or poor surgical technique can lead to recurrent neuromas 5.
- The use of a collagen conduit for recurrent neuromas has shown promising results, with 85% patient satisfaction regarding surgical outcomes 5.
- The collagen conduit technique offers comparable patient outcomes for patients with difficult neuromas, and can be used as an alternative to other surgical techniques 5.
Non-Surgical Treatments
- 4% ethanol sclerosing injection has been shown to be effective in treating Morton's neuroma, with up to 80% success rates, and can be used as a non-operational treatment option 6.
- Histologic changes have been observed in Morton's neuroma with the use of 4% ethanol sclerosing injection, contrary to findings from previous studies 6.