Morton's Neuroma

Morton's neuroma is not a true neuroma but a perineural fibrosis and nerve enlargement of the common plantar digital nerve, most often in the third web space (between the 3rd and 4th metatarsal heads). Repetitive compression in narrow toe boxes and high heels causes chronic irritation. The hallmark symptom is burning forefoot pain and tingling in the affected web space, often described as stepping on a marble or a folded-over sock.

Mulder's click — squeezing the forefoot from side to side while applying pressure in the web space — produces a palpable click and pain. Ultrasound confirms the hypoechoic perineural mass and guides injection. MRI is an alternative. Weight-bearing X-rays exclude other forefoot pathology.

1. Sclerosing ethanol injection

   Series of dilute alcohol injections can ablate the nerve.

Surgical excision is offered after 3+ failed conservative treatments including injections.

External patient-education references and related OSI pages for additional background:

• Britannica — Ankle (anatomy)
• AAOS OrthoInfo — patient education library
• OSI glossary — orthopedic terminology in plain language