Morton's neuroma is a common, paroxysmal neuralgia affecting the web spaces of the toes, typically the third. The pain is often so debilitating that individuals become anxious about walking or even putting their foot to the ground. Insoles, corticosteroid injections, excision of the nerve, transposition of the nerve and neurolysis of the nerve are commonly used treatments.

Medically Necessary:

Injections of sclerosing (neurolytic), anesthetic or steroid agents are considered medically necessary for treatment of Morton's neuroma when all of the following conservative therapies have failed:

• Padding or orthotic devices (these can provide support to reduce pressure and compression on the nerve);
• Activity modification (to reduce repetitive pressure on the nerve)
• Changes in shoe wear (i.e., shoes with a wide box toe reduce compression of the metatarsal heads and reduce pressure on the nerve)
• Medications unless otherwise contraindicated (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs] which help reduce inflammation)

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member. 

A neuroma is typically described as a benign tumor of a nerve characterized by exuberant proliferation of nerve endings. Morton's neuroma is not a tumor, but a thickening of the tissue that surrounds the digital nerve leading to the toes. It occurs as the nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. The cause of Morton's neuroma is unclear and most frequently develops between the third and fourth toes. Possible causes include nerve entrapment, the abnormal anatomy of the plantar nerve in this location, structural/mechanical foot abnormalities, trauma, or excessive pressure.

Multiple treatment approaches have been utilized for Morton's neuroma including conservative care, such as orthotics, padding, and alternative shoe styles to relieve the pressure on the forefoot. More invasive treatments include sclerosing/anesthetic/steroid injections and surgical excision of the painful nerve. The peer-reviewed literature contains varied conclusions. In a Cochrane review, Thomson and colleagues (2004) cited that there is insufficient evidence with which to assess the effectiveness of surgical and non-surgical interventions for Morton's neuroma and that well designed trials are needed to begin to establish an evidence base for the treatment of Morton's neuroma pain. Serial ethanol injection therapy has been reported to be an effective alternative to surgical excision (Fanucci, 2004). However, despite wide adoption of this treatment, no randomized, double blind, placebo-controlled study exists to verify the efficacy of this treatment in comparison to longstanding similar therapies such as corticosteroid injection.

The American College of Foot and Ankle Surgeons (ACFAS) addresses conservative and injection treatment of Morton's neuroma in their 2009 practice guideline: Diagnosis and treatment of forefoot disorders - Morton's intermetatarsal neuroma. The guideline identified the use of conservative care that focuses on elimination of pressure and irritation of the nerve. Other conservative care included injection therapies for pain relief using local anesthetic blocks, corticosteroids and neurolytic alcohol injections. However, overuse of cortisone injections was cautioned as it may result in atrophy of the plantar fat pad as well as joint subluxation.

An industry-sponsored randomized, double-blind, placebo-controlled, three-way cross-over single center clinical trial to characterize the phenotype in persons with Morton's neuroma and to explore the effect of local administration of lidocaine (NCT01298310) was completed on May 21, 2012. The trial results are currently unpublished in the peer-reviewed medical literature.

Peer Reviewed Publications:

1. Bennett GL, Graham CE, Mauldin DM. Morton's interdigital neuroma: a comprehensive treatment protocol. Foot Ankle Int. 1995; 16(12):760-763.
2. Dockery GL. The treatment of intermetatarsal neuromas with 4% alcohol sclerosing injections. J Foot Ankle Surg. 1999; 38(6):403-408.
3. Fanucci E, Masala S, Fabiano S, et al. Treatment of intermetatarsal Morton's neuroma with alcohol injection under US guide: 10-month follow-up. Eur Radiol. 2004; 14(3):514-518.
4. Hassouna H, Singh D. Morton's metatarsalgia: pathogenesis, aetiology and current management. Acta Orthop Belg. 2005; 71(6):646-655.
5. Hassouna H, Singh D, Taylor H, Johnson S. Ultrasound guided steroid injection in the treatment of interdigital neuralgia. Acta Orthop Belg. 2007; 73(2):224-229.
6. Hughes RJ, Ali K, Jones H, et al. Treatment of Morton's neuroma with alcohol injection under sonographic guidance: follow-up of 101 cases. Am J Roentgenol. 2007; 188(6):1535-1539.
7. Markovic M, Crichton K, Read JW, et al. Effectiveness of ultrasound-guided corticosteroid injection in the treatment of Morton's neuroma. Foot Ankle Int. 2008; 29(5):483-487.
8. Mozena JD, Clifford JT. Efficacy of chemical neurolysis for the treatment of interdigital nerve compression of the foot: a retrospective study. J Am Podiatr Med Assoc. 2007; 97(3):203-206.
9. Musson RE, Sawhney JS, Lamb L, et al. Ultrasound guided alcohol ablation of Morton's neuroma. Foot Ankle Int. 2012; 33(3):196-201.
10. Wu KK. Morton neuroma and metatarsalgia. Curr Opin Rheumatol. 2000; 12(2):131-142.

Government Agency, Medical Society and Other Authoritative Publications:

1. American College of Foot and Ankle Surgeons (ACFAS). Clinical Practice Guideline Forefoot Disorders Panel: Diagnosis and treatment of forefoot disorders. Section 3. Morton's intermetatarsal neuroma. J Foot Ankle Surg. 2009; 48(2):251-256.
2. AstraZeneca. A Randomized, Double-blind, Placebo-controlled, Three-way Cross-over Single Center Study to Characterize the Phenotype in Patients With Morton's Neuroma and to Explore the Effect of Local Administration of Xylocaine (Lidocaine). NLM Identifier: NCT01298310. Last updated on May 21, 2012. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01298310?term=MORTON%27S+NEUROMA&rank=2. Accessed on August 20, 2012.
3. Thomson CE, Gibson JN, Martin D. Interventions for the treatment of Morton's neuroma. Cochrane Database Syst Rev. 2004; (3):CD003118.

1. American Academy of Orthopaedic Surgeons (AAOS). OrthoInfo. Morton's neuroma. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00158. Accessed on August 20, 2012.

Intermetatarsal Neuroma