What are the diagnosis and management options for a patient with Morton's neuroma?

Diagnosis and Management of Morton's Neuroma

Diagnosis

For Morton's neuroma diagnosis, obtain radiographs first to exclude other pathology, then proceed to ultrasound or MRI as the definitive imaging modalities, both showing excellent sensitivity (US: 90%, MRI: 93%). 1, 2

Clinical Presentation

• Morton's neuroma presents as forefoot pain localized to the intermetatarsal spaces, most commonly the third webspace, caused by nerve fibrosis rather than true neuroma formation 3
• The condition affects approximately 4% of the general population with higher prevalence in females 4, 5
• Pain typically limits weight-bearing activities and footwear choices 4

Diagnostic Algorithm

1. Initial imaging: Plain radiographs to exclude alternative diagnoses including osteoarthritis, Freiberg's infraction, and stress fractures 2

2. Advanced imaging after negative/equivocal radiographs:

   • Ultrasound (sensitivity 90%) - preferred for its ability to allow clinical correlation during examination 1, 2
   • MRI without contrast (sensitivity 93%) - equally effective alternative 1, 2
   • Both modalities are recommended by the American College of Radiology as preferred imaging techniques 1, 2

Management

Corticosteroid injections should be the first-line treatment for Morton's neuroma, with 90% symptom relief rates, reserving surgery only for refractory cases. 4

Conservative Interventional Treatment (First-Line)

Corticosteroid injection technique:

• Inject 0.05-0.1 mL of triamcinolone acetonide BESIDE the neuroma, not into it 6
• Use multiple small injections around the neuroma rather than a single large intralesional injection 6
• Place injections just beneath the dermis in the upper subcutis adjacent to the neuroma 6
• This technique reduces risk of fat and dermal atrophy compared to direct intralesional injection 6

Evidence for corticosteroid efficacy:

• Demonstrated 90% symptom relief in clinical practice 4
• Meta-analysis shows VAS pain reduction of 5.3 points compared to control (95% CI: -7.5 to -3.2) 7
• Superior to footwear/padding alone (OR: 6.0,95% CI: 1.9 to 19.2) 7

Alternative Conservative Treatments

Manipulation/mobilization:

• Shows pain reduction of 15.3 points on VAS compared to control (95% CI: -29.6 to -1.0) 7
• Second strongest evidence base after corticosteroids 7

Other injection therapies with emerging evidence:

• Capsaicin injections: 51.8% VAS score reduction 5
• Sclerosing alcohol injections: Well-tolerated but require further research 7, 5
• Hyaluronic acid: Effective but needs additional study 5

Surgical Options (Reserved for Refractory Cases)

Consider surgery only after failed conservative treatment:

• Neuroma excision via dorsal approach 3
• Cryogenic or radiofrequency ablation 8
• Nerve decompression 8

Advanced Neuromodulation (Recurrent/Refractory Cases)

Peripheral nerve stimulation:

• Effective for chronic refractory cases, particularly post-surgical recurrence 8
• Can achieve near-complete pain resolution within 12 months 8
• Underutilized but promising intervention 8

Critical Pitfalls to Avoid

• Do not inject corticosteroid directly into the neuroma - this increases risk of fat atrophy and dermal complications 6
• Do not proceed to surgery without adequate trial of conservative treatment - 90% respond to injections 4
• Do not rely on radiographs alone for diagnosis - they are insensitive for Morton's neuroma detection 1, 2
• Ensure careful patient selection and pre-operative counseling if surgery becomes necessary 3