Morton’s Neuroma: What Is It?

Metatarsalgia describes pain on the forefoot and regroups several possible pathologies including bone, joint and soft tissue disorders. One of these disorders is Morton’s Neuroma (MN), an entrapment of the medial or lateral interdigital nerve leading to neuropathic pain on the forefoot (1).
In the UK, MN affects 88 and 50 in every 100,000 women and men respectively (2). The symptoms are a burning pain sensation or numbness radiating through the corresponding digits, sometimes described as walking on a pebble.
Diagnosis is mainly clinical, but ultrasound can ratify the diagnosis and rule out other disorders (3).

Why the 3rd Web Space Is Most Affected

The plantar digital nerves come from the medial and lateral plantar nerves, and because the 3rd web space receives fibres from both, it is the most affected. MN shows perineural fibrosis, axonal degeneration, oedema of the endoneurium and necrosis (4).

Not All Forefoot Pain Is Morton’s Neuroma

Not all forefoot soreness is MN. Other causes include bursitis, metatarsophalangeal joints, inflammatory arthropathy, plantar plate injury or ganglion, stress fracture (5).
Rheumatoid synovitis and nodules can mimic MN, and rheumatoid arthritis can coexist with MN (6).
Plantar plate tears may also be difficult to differentiate, and some patients receive treatment for assumed MN (7).

How Morton’s Neuroma Is Clinically Diagnosed

Clinical tests such as the thumb-finger test and Mulder click show accuracy of 96% and 62% (3,8).
However, the Mulder click can create false negatives and the thumb-finger test shows little evidence (9).
Therefore, sonography is useful to ratify suspicion and make a differential diagnosis (10).

Imagings

What Ultrasound Shows

Ultrasound can be performed from the plantar and dorsal aspects (10).

On short axis, a hypoechoic round lesion may appear between the metatarsal heads (11,12), and the sonographic Mulder sign is more likely MN than bursa (12,13,14).
The mass must be in continuity with the plantar digital nerve, as findings could mimic fibroma or ganglion (5,12).
A size more than 20 mm should raise suspicion of other pathologies (8,12).
Asymptomatic ipsilateral MN exists in 28% of cases (3).
On long axis, a fusiform hypoechoic mass in continuity with the common digital nerve is seen.
MN between 5 to 15 mm are more likely to produce symptoms (3).
MN is often associated with intermetatarsal bursal distension (15). This is why some authors use the term neuroma-bursal complex (15).

Ultrasound offers better specificity (7), dynamic imaging, lower cost and patient comfort (8).

MRI

MRI has high sensitivity and influences therapeutic decisions (16), especially when planning a surgical option.
It is more expensive and time-consuming.

However, both MRI and ultrasound can miss very small neuromas (under 5–6 mm) that may still cause significant daily symptoms.

Treatment Options

Conservative options:

Orthotics to resolve any biomechanical issue
Focused shock wave therapy (17)
Footwear modification (wide toe box, reduced high heel)
Physical therapy (calf muscle stretching)

Possible Ultrasound-guided treatments:

Guided prolotherapy (18)
Cryo-neurolysis (19)
Percutaneous needling (20)
Radiofrequency ablation (21)
Corticosteroids (more effective if associated with orthotics (22)).
Hyaluronic acid guided injection (23)

Surgery:

The surgical option would be the last resort to address the inflamed nerve tissue or decompress the area. However, Surgical treatment carries post-operative risks such as stump neuroma and recurrence (24).

Conclusion

Not all forefoot pain is caused by Morton’s neuroma. Ultrasound is often the first choice of imaging compared to MRI because it is cost-effective, accessible and provides excellent diagnostic detail.

At Sonopodiatry Clinic, we can review your forefoot symptoms to ratify or exclude Morton’s neuroma by providing a Point of care ultrasound (POCUS). We can discuss and offer initial conservative treatments such as ultrasound-guided corticosteroid injections, orthotics and focused shockwave therapy.
In cases where conservative treatment has failed, we may also consider referring you to an orthopaedic or podiatric surgeon to discuss surgical options.

Bibliography

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2-Matthews, B., Hurn, S., Harding, M., Henry, R. and Ware, R. (2019). The effectiveness of non-surgical interventions for common plantar digital compressive neuropathy (Morton’s neuroma): a systematic review and meta-analysis. [online] jfootankleres.biomedcentral.com. Available at: http://doi.org/10.1186/s13047-019-0320-7 [Accessed 11 Jul. 2019].

3-Mahadevan, D., Venkatesan, M., Bhatt, R. and Bhatia, M. (2015). Diagnostic Accuracy of Clinical Test for Morton´s neuroma compared with Ultrasonography. [online] Pdfs.semanticscholar.org. Available at: https://pdfs.semanticscholar.org/4895/55f05e316015d24d2a1fdd9663d4b85eb60f.pdf [Accessed 25 Jun. 2019].

4-Matsumoto, T., Ho Chang, S., Ozawa, N., Ohshiro, Y. and Tanaka, S. (2016). Interdigital neuroma in the second inter metatarsal Space associated with metatarsophalangeal joint instability. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5143741/pdf/CRIOR2016-9575917.pdf [Accessed 10 Jul. 2019].

5-Mehta, A., Chourasia, A., Urigo, C. and Saha, A. (2018). All forefoot’s pain are not Morton’s neuroma-a pictorial review of the forefoot musculoskeletal conditions mimicking mortons neuroma. [online] Medcraveonline.com. Available at: https://medcraveonline.com/IJRRT/IJRRT-05-00179.pdf [Accessed 28 Jul. 2019].

6-Chaganti, S., Joshy, S., Hariharan, K. and Rashid, M. (2013). Rheumatoid nodule presenting as Morton’s neuroma. [online] Link.springer.com. Available at: https://link.springer.com/content/pdf/10.1007%2Fs10195-012-0215-x.pdf [Accessed 11 Jul. 2019].

7-Stone, M., Eyler, W., Rhodenizer, J. and van Holsbeeck, M. (2017). Accuracy of Sonography in Plantar Plate Tears in Cadavers. [online] wileyonlinelibrary.com. Available at: http://doi:10.7863/ultra.16.06067 [Accessed 13 Sep. 2019].

8-Ruiz Santiago, F., Tomás Muñoz, P., Martínez Martínez, A., Pryest, P. and Prados Ollera, N. (2018). Role of imaging methods in diagnosis and treatment of Morton’s neuroma. [online] World Journal of Radiology. Available at: https://www.researchgate.net/publication/327943771_Role_of_imaging_methods_in_diagnosis_and_treatment_of_Morton’s_neuroma [Accessed 11 Jul. 2019].

9-Dando, C., Cherry, L., Jones, L. and Bowen, C. (2017). The Clinical Diagnosis of symptomatic forefoot neuroma in the general population: a Delphi consensus study. [online] Ncbi.nlm.nih.gov. Available at:

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10-Justaniah, A., Elentuck, D. and Chittenden, R. (2012). Why Ultrasonography for Morton’s neuroma. [online] Pdf.posterng.netkey.at. Available at: http://pdf.posterng.netkey.at/download/index.php?module=get_pdf_by_id&poster_id=114783 [Accessed 11 Jul. 2019].

11-Beard, N. and Gousse, R. (2018). Current Ultrasound Application in the foot and Ankle. [online] Spoc-ortho.com. Available at: https://www.spoc-ortho.com/sites/spoc-orthoV2.com/files/news-events/Current%20Ultrasound%20Application%20in%20the%20Foot%20and%20Ankle.pdf [Accessed 12 Jun. 2019].

12-Drakonaki, E., Allen, G. and Watura, R. (2015). Ultrasound-guided intervention in the ankle and foot. [online] Birpublications.org. Available at: https://www.birpublications.org/doi/pdf/10.1259/bjr.20150577 [Accessed 11 Jul. 2019].

13-De Maeseneer, M., Madani, H. and Lenchik, L. (2015). Normal anatomy and compression areas of nerves of the foot and ankle: Us and MR imaging with anatomic correlation. [online] Pubs.rsna.org. Available at: https://pubs.rsna.org/doi/pdf/10.1148/rg.2015150028 [Accessed 10 Jul. 2019].

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15-Cohen, S., Miller, T., Ellis, S., Roberts, M. and Dicarlo, E. (2016). Sonography of Morton Neuromas, what are we really looking at?. [online] Onlinelibrary.wiley.com. Available at: https://onlinelibrary.wiley.com/doi/pdf/10.7863/ultra.15.11022 [Accessed 11 Jul. 2019].

16-Torres-Claramunt, R., Pidemunt, G., de Zabala, S., Ginés, A. and Puig, L. (2012). MRI and ultrasonography in Morton′s neuroma: Diagnostic accuracy and correlation. [online] ncbi. Available at: http://doi:10.4103/0019-5413.96390 [Accessed 29 Aug. 2019].

17-Seok, H. et al. (2016) ‘Extracorporeal Shockwave Therapy in Patients with Morton’s Neuroma’, Journal of the American Podiatric Medical Association, 106(2), pp. 93–99. Available at: https://doi.org/10.7547/14-131.

18-Hauser, R., Feister, W. and Brinker, D. (2012). Dextrose Prolotherapy Treatment for Unresolved “Morton’s Neuroma” Pain. [online] Prolotherapy.com. Available at: https://prolotherapy.com/HauserMortonsNeuroma.PDF [Accessed 11 Jul. 2019].

19-Katz, M. (2013). A Closer Look At Cryosurgery For Neuromas. [online] Podiatry Today. Available at: https://www.podiatrytoday.com/closer-look-cryosurgery-neuromas [Accessed 21 Jul. 2019].

20-Atilano, L., Martin, J., Iglesias, G. and Andia, I. (2015). Percutaneous needling of Morton’s complex: a technical note. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4762639/pdf/280-283.pdf [Accessed 25 Jul. 2019].

21-Gougoulias, N., Lampridis, V. and Sakellariou, A. (2019). Morton´s interdigital neuroma: instructional review. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6362341/pdf/eor-4-14.pdf [Accessed 25 Jun. 2019].

‌22-Orlandi, D., Messina, C., Corazza, A., Serafini, G. and Silvestri, E. (2015).ECR 2015 / C-1701 /Ultrasound-guided Treatment of Morton’s Syndrome: comparison among three different injection techniques – EPOS™. [online] Posterng.netkey.at.Available at: http://posterng.netkey.at/esr/viewing/index.php?module=viewing_poster&task=viewsection&pi=128098&si=1477 [Accessed 11 Jul. 2019].

23-Togay Koç (2024) Ultrasound-guided infiltration with hyaluronic acid versus corticosteroid for the treatment of Morton’s neuroma: a randomised controlled trial, BOFAS. Available at: https://www.bofas.org.uk/clinician/meetings/bofas-abstract-archive/ultrasound-guided-infiltration-with-hyaluronic-acid-versus-corticosteroid-for-the-treatment-of-mortons-neuroma-a-randomised-controlled-trial (Accessed: 16 October 2025).

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