Some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads, as originally proposed by Morton, is highly unlikely, because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads. It is more likely that the transverse metatarsal ligament is the cause of the entrapment. Despite the name, the condition was first correctly described by a chiropodist named Durlacher, and although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).
Although the exact cause for this condition is unclear, a number of factors can contribute to the formation of a neuroma. Biomechanical deformities, such as a high-arched foot or a flat foot, can lead to the formation of a neuroma. These foot types bring on instability around the toe joints, leading to the development of the condition. Trauma can cause damage to the nerve, resulting in inflammation or swelling of the nerve. Improper footwear that causes the toes to be squeezed together is problematic. Avoid high-heeled shoes higher than two inches. Shoes at this height can increase pressure on the forefoot area. Repeated stress, common to many occupations, can create or aggravate a neuroma.
A Morton's neuroma usually causes burning pain, numbness or tingling at the base of the third, fourth or second toes. Pain also can spread from the ball of the foot out to the tips of the toes. In some cases, there also is the sensation of a lump, a fold of sock or a "hot pebble" between the toes. Typically, the pain of a Morton's neuroma is relieved temporarily by taking off your shoes, flexing your toes and rubbing your feet. Symptoms may be aggravated by standing for prolonged periods or by wearing high heels or shoes with a narrow toe box.
Morton's neuroma is usually diagnosed by your doctor listening to your symptoms and examining your foot. Sometimes your doctor can feel the 'neuroma', or an area of thickening in your foot, which may be tender. Sometimes, your doctor may suggest an ultrasound scan or MRI scan to confirm the diagnosis but this is not always necessary. Some doctors inject a local anaesthetic into the area where you are experiencing pain. If this causes temporary relief of pain, burning and tingling, it can sometimes help to confirm the diagnosis and show the doctor where the problem is.
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.
The ultimate success of a Morton?s neuroma treated surgically can be variable. In cases where the underlying problem is only an irritated nerve (a true Morton?s neuroma), then surgery will probably be curative (although it may take a few months for the foot to fully heal). But in many cases, forefoot pain is more complex. There may be an irritated nerve or two causing pain, but the real problem is often excessive loading of the lesser metatarsals. The generic term for this condition is metatarsalgia. When considering surgery, identifying and addressing these problems may lead to a better end result.