What Causes Mortons Neuroma

Overview

Morton neuromaMorton’s neuroma (also known as Morton neuroma, Morton’s metatarsalgia, Morton’s neuralgia, plantar neuroma, intermetatarsal neuroma, and interdigital neuroma) is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces (between 2nd-3rd and 3rd-4th metatarsal heads), which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by removing footwear.

Causes

The pain of Morton’s neuroma occurs when the nerve connecting the toe bones (metatarsal bones) becomes irritated or compressed. The exact cause of the irritation is unknown, but it may be the metatarsal bones pressing against the nerve when the gap between the bones is narrow. This causes the nerve and surrounding tissue to thicken. Some experts believe that a number of other foot problems, including flat feet, high foot arches, bunions and hammer toes, may also play a role in Morton’s neuroma.

Symptoms

Episodes of pain are intermittent. Patients may experience 2 attacks in a week and then none for a year. Recurrences are variable and tend to become more frequent. Between attacks, no symptoms or physical signs occur. Two neuromas coexist on the same foot about 2-3% of the time. Other diagnoses should be considered when 2 or more areas of tenderness are present.

Diagnosis

Patients with classic Morton?s neuroma symptoms will have pain with pressure at the base of the involved toes (either between the 2nd and 3rd toes, or between the 3rd and 4th toes). In addition, squeezing the front of the foot together can exacerbate symptoms. As well, they may have numbness on the sides of one toe and the adjacent toe, as this corresponds with the distribution of the involved nerve.

Non Surgical Treatment

Treatment for Morton’s neuroma may depend on several factors, including the severity of symptoms and how long they have been present. The earlier on the condition is diagnosed, the less likely surgery is required. Doctors will usually recommend self-help measures first. These may include resting the foot, massaging the foot and affected toes. Using an ice pack on the affected area (skin should not be directly exposed to ice, the ice should be in a container or wrapped in something) Changing footwear, wearing wide-toed shoes, or flat (non high-heeled) shoes. Trying arch supports (orthotic devices). A type of padding that supports the arch of the foot, removing pressure from the nerve. The doctor may recommend a custom-made, individually designed shoe-insert, molded to fit the contours of the patient’s foot. There are several OTC (over the counter, non-prescription) metatarsal pads or bars available which can be placed over the neuroma. Taking over-the-counter, non-prescription painkilling medications. Modifying activities, avoiding activities which put repetitive pressure on the neuroma until the condition improves. Bodyweight management,if the patient is obese the doctor may advise him/her to lose weight. A significant number of obese patients with foot problems, such as flat feet, who successfully lose weight experience considerable improvement of symptoms.Morton neuroma

Surgical Treatment

Interdigital neurectomy (removal of the diseased nerve) in right hands, should give satisfactory results almost all the time. Some of the reasons behind failure is when not enough nerve is dissected, mistakes in initial diagnosis, or bad handling of adjacent nerves, tendons and joint capsules during the operation. It is very common and acceptable to have some numbness in the area where the nerve used to be. This never causes any discomfort and often gets better in few years. It is crucial to address the biomechanical pathologies underlying the impingement of the nerve during and after the surgery.

Prevention

Wearing proper footwear that minimizes compression of the forefoot can help to prevent the development of and aggravation of a Morton’s neuroma.

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