What is Morton’s neuroma?
Morton’s neuroma is a benign enlargement and irritation of one of the small nerves that run between the metatarsal bones in the forefoot. Although it is called a “neuroma,” it is not a true nerve tumour and it is not a cancer.
The condition most commonly affects the third intermetatarsal space, between the third and fourth metatarsal bones. Less commonly, it can occur between the second and third metatarsals.
Understanding the anatomy of the forefoot
Several interdigital nerves travel through the forefoot and supply sensation to the toes. These nerves pass beneath the deep transverse metatarsal ligament, a structure that connects the metatarsal heads and stabilises the forefoot.
Because the nerve passes through a relatively confined space, repeated compression between the metatarsal heads can irritate the nerve and eventually lead to swelling, fibrosis and hypersensitive pain signalling.
Why does Morton’s neuroma develop?
Morton’s neuroma usually develops gradually. Repeated mechanical stress squeezes the nerve between adjacent metatarsal heads. Over time, this can cause local inflammation, perineural fibrosis, nerve enlargement and altered nerve signalling.
- Repeated forefoot compression and mechanical trauma
- Local inflammation around the interdigital nerve
- Scar-like fibrous tissue developing around the nerve
- Nerve thickening and enlargement
- Hypersensitive pain signals from the affected nerve
Who is most likely to develop Morton’s neuroma?
Morton’s neuroma is seen more commonly in women and is often diagnosed in middle-aged adults, especially between 40 and 60 years of age. It may also affect runners, dancers and athletes involved in repetitive impact activities.
Important risk factors include tight footwear, high heels, narrow toe-box shoes, flat feet, high arches, bunions, forefoot instability and repetitive running or jumping sports.
What does Morton’s neuroma feel like?
Symptoms vary, but patients often describe burning pain in the ball of the foot, tingling into the toes, numbness, electric shock sensations and the feeling of walking on a pebble or folded sock.
- Burning forefoot pain
- Tingling into adjacent toes
- Numbness, commonly affecting the third and fourth toes
- Sharp shooting or electric shock-like discomfort
- A sensation that there is a stone inside the shoe
Symptoms often worsen with walking, running, prolonged standing or tight shoes, and may improve when the shoes are removed, the foot is massaged or the patient rests.
How is Morton’s neuroma diagnosed?
Diagnosis starts with a clinical history and physical examination. A clinician may compress the forefoot, assess tenderness and attempt to reproduce the symptoms. Imaging is often used when the diagnosis is uncertain or when other causes of forefoot pain need to be excluded.
The role of ultrasound in Morton’s neuroma
Musculoskeletal ultrasound is one of the most useful imaging tools for Morton’s neuroma. It can identify the affected interdigital nerve, assess its size and location, and evaluate surrounding soft tissues.
A typical Morton’s neuroma appears as a hypoechoic, ovoid or spindle-shaped lesion in the intermetatarsal space. It is usually non-compressible and can be assessed dynamically while the forefoot is compressed or moved.
What is Mulder’s sign?
Mulder’s sign is a classic clinical finding. When the forefoot is compressed, the neuroma may move, a palpable click may occur and the patient’s symptoms may be reproduced. Ultrasound can demonstrate this dynamic behaviour during scanning.
Conditions that can mimic Morton’s neuroma
Several conditions can produce similar pain, tingling or forefoot discomfort. Ultrasound helps differentiate Morton’s neuroma from other soft tissue and joint-related causes.
- Intermetatarsal bursitis
- Plantar plate injury
- Stress fractures or stress reactions
- Arthritis of the metatarsophalangeal joints
- Peripheral neuropathy, including diabetes-related neuropathy
- Ganglion cysts and other soft tissue masses
Ultrasound versus MRI
For many patients, ultrasound is an excellent first-line investigation because it is dynamic, lower cost, rapidly accessible, accurate in experienced hands and can guide injections. MRI can be useful when broader assessment is needed or when the presentation is complex.
Treatment options for Morton’s neuroma
Treatment depends on symptom severity and the impact on daily life. Mild symptoms may improve with conservative management, while longstanding or severe symptoms may require image-guided injection or surgical opinion.
- Footwear modification: wider toe box, lower heel height and better forefoot support.
- Orthotics: pressure redistribution and improved biomechanics.
- Physiotherapy: gait, loading pattern and foot mechanics advice.
- Ultrasound-guided corticosteroid injection: targeted treatment to reduce inflammation and nerve irritation.
- Surgery: decompression or neuroma excision in selected severe cases when conservative treatment fails.
When should you seek medical advice?
You should seek assessment if you have persistent burning forefoot pain, toe numbness, tingling, walking-on-a-pebble sensation or symptoms that affect daily activities. Early assessment can help identify the cause and guide treatment.
Final thoughts
Morton’s neuroma is a common cause of forefoot pain and can cause burning pain, numbness, tingling and the classic sensation of walking on a pebble. It develops due to chronic compression and irritation of an interdigital nerve, leading to nerve enlargement and fibrosis.
Musculoskeletal ultrasound can help diagnose Morton’s neuroma, exclude alternative causes and guide treatment where necessary. Early recognition and appropriate management can significantly improve symptoms and help patients return to normal activity.
References and clinical review
This article draws on patient information and clinical guidance sources including NHS foot pain resources, British Orthopaedic Foot & Ankle Society information, AAOS information on Morton’s neuroma, BMUS musculoskeletal ultrasound guidance, ESSR musculoskeletal ultrasound guidance, Radiopaedia and sports medicine literature.
Article preparation and clinical review: Prepared with AI-assisted editorial support and reviewed for clinical accuracy by Dr Pedram Aghaei — Vascular Scientist, SVT reg. SVT 679 · Registered Clinical Technologist, RCT reg. 93290, BMUS 20702; and Dr Hosna Rashidi — BMUS 29386, SVT reg. M11114.
This article is intended for general patient information only and does not replace a medical consultation.