Morton metatarsalgia N070

Current RMA Instruments

Changes from previous Instruments

ICD Coding

• ICD-9-CM Codes: 355.6
• ICD-10-AM Codes: G57.6

Brief description

This is a peripheral nerve entrapment or impingement in the forefoot, between the metatarsals. See comments below.

Confirming the diagnosis

Diagnosis is normally based on the clinical presentation, together with imaging (ultrasound or MRI) of the forefoot.  

The relevant medical specialist is an orthopaedic surgeon or neurologist.

Additional diagnoses covered by SOP

• Morton's neuroma
• Morton’s neuralgia
• Plantar nerve entrapment neuropathy
• Interdigital neuroma of the foot

Conditions excluded from SOP

• Diabetic neuropathy* - peripheral neuropathy SOP
• Metatarsalgia (unspecified) - not a disease or injury
• Peripheral neuropathy*
• Peripheral vascular disease* - Atheroscerlotic peripheral vascular disease SOP
• Plantar fasciitis*
• Tarsal tunnel syndrome^#

* another SOP applies

^# non-SOP condition

Clinical onset

Clinical onset will be when relevant symptoms, subsequently confirmed to be due to Morton metatarsalgia, first began.

Clinical worsening

Clinical worsening may be evidenced by an increase in symptoms or by imaging evidence of progression of neuroma.

Comments

Morton refers to the American surgeon Dr Thomas Morton (1835-1903) who first described this type of metatarsalgia.

It is the interdigital plantar nerve which becomes trapped or impinged. This mechanical impingement leads to pain (metatarsalgia). Trapping a peripheral nerve can also lead to numbness and paraesthesias (pins & needles).

This is a specific pathology and is not synonymous with metatarsalgia.