Morton's Neuroma: Clinical Presentation
Morton's neuroma presents as paroxysmal, burning or sharp pain in the forefoot webspace, most commonly between the third and fourth metatarsals, often so severe that patients become anxious about weight-bearing or walking. 1, 2
Typical Clinical Features
Location and Pain Characteristics
- The third intermetatarsal space is the most common location, followed by the second webspace 1
- Pain is described as burning, sharp, or stabbing sensations radiating into the toes 2, 3
- Numbness on the forefoot frequently accompanies the pain 3
- The pain is paroxysmal in nature, occurring in episodes rather than continuously 2
Functional Impact
- Patients experience significant functional impairment affecting weight-bearing activities 4
- Walking becomes severely limited, with many patients anxious about even putting their foot to the ground 2
- Appropriate footwear becomes difficult to tolerate due to pain and discomfort 4
Patient Demographics
- Females are predominantly affected 4
- Average age of presentation is approximately 45 years 4
- The condition affects approximately 4% of the general population 5
Diagnostic Approach
Initial Evaluation
- Begin with radiographs to exclude other causes of webspace pain including osteoarthritis, Freiberg's infraction, and stress fractures 6
- Radiographs are insensitive for Morton's neuroma itself but essential for differential diagnosis 7
Advanced Imaging
- After negative or equivocal radiographs, proceed to ultrasound or MRI 6
- Both modalities show high sensitivity: MRI 93%, ultrasound 90% 7, 6
- Ultrasound has the advantage of allowing clinical correlation during real-time examination 7, 6
- The American College of Radiology recommends both ultrasound and MRI as preferred imaging modalities 7, 6
Pathophysiology
- Morton's neuroma is not a true neuroma but rather fibrosis of the digital nerve 1
- The fibrosis develops secondary to pressure or repetitive irritation causing nerve thickening 1
Management Algorithm
First-Line Conservative Treatment
- Corticosteroid injections are the primary conservative interventional treatment, with 90% symptom relief in recent studies 4
- Inject 0.05-0.1 mL of triamcinolone acetonide beside (not into) the neuroma using multiple small injections around the lesion 8
- Direct injection into the neuroma carries higher risk of fat and dermal atrophy 8
Alternative Infiltrative Options
- Capsaicin injections produce VAS score reduction of 51.8% 5
- Alcohol sclerosing injections and hyaluronic acid are well-tolerated but require further research 5
- All infiltrative treatments show no serious adverse events 5
Surgical Consideration
- Reserve surgical excision only for patients who fail conservative treatment 4
- Surgical options include nerve excision (most common), nerve transposition, or neurolysis 1, 2
- There is limited evidence suggesting nerve transposition may yield better long-term results than standard resection 2
Common Pitfall
- Avoid direct intralesional injection into the neuroma itself, as this increases complications without improving outcomes 8