Foot / Ankle
Morton's Neuroma
모르통 신경종
Perineural fibrosis of forefoot interdigital nerve causing pain and numbness — usually 3rd-4th interspace
- How common
- Uncommon
- Typical age
- Ages 30–60
What is it?
Perineural fibrosis of interdigital nerve (not a true neuroma — reactive peritendinous fibrosis) in intermetatarsal space
Commonly affected: Common digital nerve in intermetatarsal space (usually 3rd-4th, 2nd-3rd also possible)
How it develops
- Nerve CompressionCommon digital nerve repeatedly compressed between metatarsal heads in narrow forefoot
- Perineural FibrosisRepetitive compression causes perineural connective tissue thickening (reactive fibrosis, not true neuroma)
- Common Digital Nerve DamageNerve thickening and demyelination cause pain and sensory changes in common digital nerve distribution
- Narrow Shoe AggravationTight shoes increase forefoot compression → symptom exacerbation
Symptoms
- Interdigital Burning PainBurning pain between 3rd-4th (or 2nd-3rd) toes, radiating to toes
- Shoe WorseningWorsens with tight shoes — relieved by removing shoes (very helpful for diagnosis)
- Pebble SensationSensation of pebble in shoe while walking — palpating thickened nerve
- Toe NumbnessNumbness or reduced sensation on adjacent toe surfaces
How it is examined
- Mulder's Click TestMediolateral forefoot squeeze + interdigital space pressure → click with pain → Positive (Mulder's click)
- Interdigital Space TendernessDirect pressure in 3rd-4th interspace reproduces burning pain
- Toe Spread TestSpreading 3rd-4th toes apart reproduces pain → nerve tension
Imaging
Usually normal. Exclude metatarsal stress fracture, MTP joint pathology
- Usually normal
- Metatarsal stress fracture exclusion
- MTP joint abnormalities if present
Confirm neuroma size and location, pre-surgical planning — consider surgery if >5mm diameter
- Low signal lesion in intermetatarsal space (T1-T2)
- Nerve thickening between metatarsal heads
- Neuroma size measurement (surgical planning criterion)
Non-surgical care
- Shoe ModificationWide toe box shoes, low-heeled footwear — most important first step
- Metatarsal Pad/OrthoticsMetatarsal pad opens intermetatarsal space → reduces nerve compression
- Steroid InjectionInterdigital space steroid injection — 60-70% short-term efficacy
- Alcohol Sclerosing InjectionDiluted ethanol injection for chemical neurolysis — conservative alternative
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Failed conservative treatment 6 months, neuroma size >5mm, severe symptoms
Procedures that may be discussed
- Neurectomy — dorsal or plantar approach
- Nerve decompression/release — nerve preservation aim
Outlook
50-60% conservative improvement. 80-85% pain relief after surgical neurectomy. Permanent interdigital numbness possible post-surgery