Is Injection Therapy The Best Solution for Foot Neuromas?

Gary Dockery, DPM

Foot neuromas are very common findings, especially those that are termed intermetatarsal neuromas (or interdigital neuromas). The painful condition is believed to be caused by sensory nerve irritation, injury or abnormal mechanics of the foot. Yes, there are conservative care modalities as well as surgical treatment measures. However, I believe chemical neurolysis (using a dilute solution of ethyl alcohol) gives us a viable alternative for treating the foot neuroma as it has fewer potential complications and up to an 89 percent success rate.1
First things first. When it comes to diagnosing neuromas, be on the lookout for symptoms that may range from numbness, tingling, sharp pain or muscle cramping in the foot or toes.2 Taking an accurate history and performing a good clinical examination is usually all that is necessary to make the primary diagnosis of neuroma formation. More sophisticated and costly forms of diagnostic techniques, such as ultrasonographic evaluation, are slowly becoming more prevalent in diagnosing neuromas.3
Taking A Closer Look At The Treatment Options
The standard treatment for these conditions is relatively limited and includes the conservative care options of massage, tape strapping of the foot, functional orthotic foot devices, change in shoe type or style, decreased physical activities, and one or more cortisone injections into the involved area. Complications with the different forms of conservative treatments vary but may include failure to improve the symptoms, difficulty in wearing certain shoes, worsening of the condition, cortisone atrophy or discoloration of the skin.
When these conservative measures fail to relieve the patient’s symptoms, then surgical treatment is often recommended. The surgical treatment options include completely excising the neuroma, doing internal or external surgical neurolysis, transferring the involved nerve tissue without cutting the nerve, and, in some cases, performing adjacent osseous procedures. As far as surgical incisions go, you would make them directly over the neuroma, longitudinally on the dorsal or plantar aspect of the foot between the metatarsals or transversely on the ball of the foot.
However, be aware that surgical complications may include painful or unsightly incisional scar formation, deep tissue adhesions or fibrose tissue formation, creation of a “stump” neuroma, incisional wound dehiscence, postoperative infection and swelling.4 Many patients complain of an unpleasant sensation following nerve surgery that is difficult for them to accurately describe. Even when you’ve greatly improved the painful neuroma symptoms, you may hear post-operative comments such as “it feels funny,” “it feels weird,” “it feels like there is a lump in my sock” or “I just don’t like how it feels.”
How To Create The Sclerosing Solution
For Injection Therapy
The injection treatment technique for neuromas is credited to the late Dr. Marvin D. Steinberg.5 I first heard Dr. Steinberg lecture on the subject of dilute alcohol injections and Vitamin B-12 injections for neuromas in 1973 while I was attending the Ohio College of Podiatric Medicine in Cleveland. That same year, Max Weisfeld published his paper on treating porokeratosis plantaris discreta with 4% ethyl alcohol injections.6 At that point in my training, I became a devout student of the effects of dilute alcohol injections on nerves and keratotic lesions.
I have previously described the technique of using a sclerosing solution of 4% mixture of ethanol to treat foot neuromas, both those that have failed previous conservative treatments and for those cases of recurrent or stump neuroma formation.7
You can create the 4% alcohol sclerosing solution by mixing 48 ml of a local anesthetic agent with 2 ml of absolute (dehydrated or desiccated) ethyl alcohol (ethanol). I have used pure ethanol for injection, USP, and 0.5% bupivacaine HCl with epinephrine (1:2000,000) for most mixtures. You can also make the 4% dilution of alcohol with 48 ml of 2% lidocaine plain and 48 ml of pure ethyl alcohol, but I have had much better results with the bupivacaine-epinephrine combination.

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