Morton’s neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton’s neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
The source of this pain is an enlargment of the sheath of an intermetatarsal nerve in the foot. This usually occurs in the third intermetatarsal space, the space between the third and fourth toes and metatarsals. It occurs here, at the site third intermetatarsal nerve, since this intermetatarsal nerve is the thickest being comprised of the joining of two different nerves. It also may occur in the other intermetatarsal areas, with the second interspace being the next most common location.
Symptoms of interdigital neuroma typically manifest as a sharp, burning or tingling sensation in the forefoot. The pain radiates toward the lesser toes and is aggravated by shoe wear. The pain is relieved when the shoe is removed and the forefoot is massaged. Sometimes the symptoms involve specific toes.
Your health care provider can usually diagnose this problem by examining your foot. A foot x-ray may be done to rule out bone problems. MRI or ultrasound can successfully diagnose the condition. Nerve testing (electromyography) cannot diagnose Morton neuroma. But it may be used to rule out conditions that cause similar symptoms. Blood tests may be done to check for inflammation-related conditions, including certain forms of arthritis.
Non Surgical Treatment
Wear shoes with plenty of room for the toes to move, low heels, and laces or buckles that allow for width adjustment. Wear shoes with thick, shock-absorbent soles, as well as proper insoles that are designed to keep excessive pressure off of the foot. High-heeled shoes over two inches tall should be avoided whenever possible because they place undue strain on the forefoot. Resting the foot and massaging the affected area can temporarily alleviate neuroma pain. Use an ice pack to help to dull the pain and improve comfort. Use over-the-counter shoe pads. These pads can relieve pressure around the affected area.
When early treatments fail and the neuroma progresses past the threshold for such options, podiatric surgery may become necessary. The procedure, which removes the inflamed and enlarged nerve, can usually be conducted on an outpatient basis, with a recovery time that is often just a few weeks. Your podiatric physician will thoroughly describe the surgical procedures to be used and the results you can expect. Any pain following surgery is easily managed with medications prescribed by your podiatrist.