What type of injection is best for treating Morton's neuroma?

Best Injection Treatment for Morton's Neuroma

Ultrasound-guided corticosteroid injection is the most effective first-line injection treatment for Morton's neuroma, providing superior pain relief compared to blind injections and serving as a cost-effective option before considering surgery. 1, 2

Diagnostic Confirmation

Before proceeding with any injection therapy:

• Confirm diagnosis with imaging
  • Ultrasound: 90% sensitivity, 88% specificity (preferred initial imaging)
  • MRI: 87% sensitivity, 100% specificity (alternative option) 1

Injection Treatment Algorithm

First-Line Treatment:

• Ultrasound-guided corticosteroid injection
  • Composition: 1 mL methylprednisolone (40 mg) + 1 mL 2% lidocaine 3
  • Benefits:
    • Provides significant pain relief for at least 3 months 3
    • Ultrasound guidance ensures accurate placement and reduces side effects 2
    • Success rate: >60% short-term pain relief 2

If First-Line Treatment Fails:

• Consider sequential approach with alcohol sclerosing injections
  • A sequential approach of corticosteroid followed by alcohol injections before considering surgery is the most cost-effective strategy (ICER: $4,401.61/QALY compared to no treatment) 4

Advantages of Ultrasound-Guided vs. Blind Injections:

• Ultrasound-guided injections provide:
  • Statistically significant improvement at 45 days, 2 months, and 3 months post-injection 2
  • Lower rate of skin side effects 2
  • More accurate placement of medication 5

Practical Considerations

1. Injection technique:

   • Position patient supine with foot relaxed
   • Use high-frequency linear transducer for ultrasound guidance
   • Direct needle from dorsal approach into the affected web space
   • Ensure medication surrounds the neuroma

2. Follow-up:

   • Assess response at 1 month, 45 days, and 3 months
   • If inadequate response after 3 months, consider repeat injection or progression to alcohol sclerosing injections

3. Cautions:

   • Limit number of corticosteroid injections (typically no more than 3) to avoid fat atrophy and skin changes
   • Monitor for temporary post-injection pain flare

When to Consider Surgery

• Consider surgical neurectomy only after failure of sequential injection therapy
• A trial of ultrasound-guided injections before surgery is more cost-effective than proceeding directly to surgical neurectomy 4

Summary

For Morton's neuroma requiring injection therapy, ultrasound-guided corticosteroid injection represents the optimal first-line approach, with superior outcomes compared to blind injections. If needed, a sequential approach adding alcohol sclerosing injections provides the most cost-effective treatment pathway before considering surgical intervention.