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).
In many cases, a neuroma may develop as a result of excessive loading on the front of the foot. Sometimes, a patient?s anatomic alignment in the forefoot contributes to the overload. There may be some cases where the neuroma develops spontaneously, for no obvious reason. However, once the nerve is irritated, pressure from walking, and from the adjacent bony prominences (metatarsal heads), as well as from the intermetatarsal ligament that binds the heads together, all may contribute to persistent pain. Repetitive pressure on the nerve causes localized injury with resulting scarring and fibrosis of the nerve. This leads to symptoms in the distribution of the nerve.
People with Morton’s neuroma usually complain of pain that can start in the ball of the foot and shoot into the affected toes. However, some people just have toe pain. There may also be burning and tingling of the toes. The symptoms are usually felt up the sides of the space between two toes. For example, if the nerve between the third and fourth long bones (metatarsals) of the right foot is affected, the symptoms will usually be felt up the right-hand side of the fourth toe and up the left-hand side of the third toe. Some people describe the pain that they feel as being like walking on a stone or a marble. Symptoms can be made worse if you wear high-heeled shoes. The pain is relieved by taking your shoe off, resting your foot and massaging the area. You may also experience some numbness between the affected toes. Your affected toes may also appear to be spread apart, which doctors refer to as the ‘V sign’. The symptoms can vary and may come and go over a number of years. For example, some people may experience two attacks of pain in a week and then nothing for a year. Others may have regular and persistent (chronic) pain.
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 high-resolution ultrasound can successfully diagnose Morton’s neuroma. Nerve testing (electromyography) cannot diagnose Morton’s neuroma, but 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
If your Morton’s neuroma is painful, your doctor usually will begin treatment with conservative therapies, including a switch to shoes with low heels, wide toes and good arch support. Padding techniques, including metatarsal pads or toe crest pads. Shoe inserts (orthotics) to help correct any mechanical imbalance in the foot. Anti-inflammatory medication, such as ibuprofen (Advil, Motrin and other brand names) or naproxen (Aleve, Naprosyn and other brand names) A local injection of anesthetic and corticosteroid medication into the affected area. Inflamed or injured nerves can take months to improve, even after the underlying problem has been corrected.
The above measures are often sufficient to resolve Morton?s Neuroma. Should the condition persist or worsen despite these efforts, surgery may be recommended to remove the Neuroma. The surgery requires only a short recovery period, though permanent numbness in the affected toes can result, so such surgery is generally used as a last resort.