Morton's neuroma has been known by several other names: morton's metatarsalgia, morton's neuralgia, plantar neuroma and intermetatarsal neuroma.
Patients will often complain of pain and/or numbness of their forefoot in between the 2nd and 3rd or 3rd and 4th metatarsals heads. The pain is usually elicited by shoe gear (pain when the toes are pressed together inside of the shoe) or with a pressing motion (such as pressing on the brake during driving), or walking.
The term was first described by Chiropodist Lewis Durlacher in 1845. Although it is a called a neuroma, it is believed to be a perineural fibroma rather than a true tumor. Although the best way to visualize a neuroma is by ultrasound or MRI, a standard x-ray may also be taken to rule out any trauma like fractures or a bone lesion or arthritis. A standard x-ray will not typically show soft tissue lesions.
Treatment of Morton's Neuroma
An ultrasound can also be used to guide therapeutic Cortisone injections to alleviate painful symptoms associated with the Morton's Neuroma. Widely used forms of conservative treatments for Morton's Neuroma are orthotics and corticosteroid injections. In addition to traditional orthotic arch supports, a small foam or fabric pad may be positioned under the space between the two affected metatarsals. This pad helps to separate the metatarsal bones and create more space for the nerve so as to relieve pressure and irritation. Unfortunately, it may cause mildly uncomfortable sensations of its own, such as the feeling of having an awkward object under one's foot.
Corticosteroid injections can relieve inflammation and pain in some patients and help to alleviate the symptoms. However, the inflammation and pain recur after some weeks or months, and corticosteroids can only be used a limited number of times because they cause damage to the ligaments and tendons of the foot.
Sclerosing alcohol injections are also a treatment alternative if other conservative methods fail. A direct injection of 4% alcohol can be placed into the area of the neuroma, causing toxicity to the fibrous nerve tissue. Most often, this treatment must be performed 2–4 times at 1–3 weeks intervals.
Another treatment modality of Morton's Neuroma is Radio Frequency Ablation. The effectiveness of the treatment is speculative. Surgery is often the last resort and a procedure known as neurectomy (which involves removing the affected piece of nerve tissue), may be performed. A postoperative scar tissue formation (stump neuroma) can occur in approximately 20% of cases, causing a return of neuroma symptoms.