Neuromas are generally benign or non-cancerous growths of nerve tissue, developing in various parts of the body. Morton?s Neuromas are confined to the nerves of the foot, most commonly, between the third and fourth toes. The condition involves a thickening of the tissue around one of the digital nerves leading to the toes and does not qualify as an actual tumor. The affliction causes a sharp, burning pain, usually in the region of the ball of the foot. A patient?s toes may also sting, burn or exhibit numbness. Often, the symptoms have been likened to ?walking on a marble.?
A Morton?s Neuroma are a result of complex biomechanical changes that occur in your feet. There are a number of theories as to the exact cause of the scarring and thickening, but it basically boils down to overload of the tissue structure. The body lays down scar tissue to try to protect the overloaded structure. Tight-fitting shoes may exacerbate a Morton?s Neuroma. Shoes such as high heels and shoes with tight toe boxes (eg womens fashion shoes and cowboy boots) are particularly damaging to the toes. These shoes have a sloping foot bed and a narrow toe box. The slope causes the front of the foot to bear your weight. The angle of the toe box then squeezes your toes together. Footwear is not the only cause of a Morton?s Neuroma. Injuries to the foot can also be a factor in developing the condition by changing your foot biomechanics. Poor foot arch control leading to flat feet or foot overpronation does make you biomechanically susceptible to a neuroma.
Symptoms include: pain on weight bearing, frequently after only a short time. The nature of the pain varies widely among individuals. Some people experience shooting pain affecting the contiguous halves of two toes. Others describe a feeling like having a pebble in their shoe or walking on razor blades. Burning, numbness, and paresthesia may also be experienced. Morton’s neuroma lesions have been found using MRI in patients without symptoms.
Plain x-rays of the foot may demonstrate that one or more of the metatarsals are long (Figure #5). Not uncommonly, the second and/or third metatarsal may be long relative to the third or fourth. This can create a situation where excessive load is occurring in and around the vicinity of the interdigital nerve.
Non Surgical Treatment
In most cases, initial treatment for this condition consists of padding and taping to disperse weight away from the neuroma. If the patient has flatfeet, an arch support is incorporated into footwear. The patient is instructed to wear shoes with wide toe boxes and avoid shoes with high heels. An injection of local anesthetic to relieve pain and a corticosteroid to reduce inflammation may be administered. The patient is advised to return in a week or 2 to monitor progress. If the pain has been relieved, the neuroma is probably small and caused by the structure of the patient’s foot and the type of shoes the patient wears. It can be relieved by a custom-fitted orthotic that helps maintain the foot in a better position. Another type of therapy that may be used is alcohol sclerosing injections. In this treatment, the doctor injects a small amount of alcohol in the area of the neuroma area to help harden (sclerose) the nerve and relieve the pain. Injections are given every 7-10 days and, in many cases, 4-7 injections are needed for maximum relief. Please ask your physician for more information regarding this type of treatment.
Majority of publications including peer review journal articles, surgical technique description and textbooks promote surgical excision as a gold standard treatment. Surgical excision is described as the most definitive mode of treatment for symptomatic Morton?s neuroma with reported success rates varying between 79% and 93%. Various surgical techniques are described, essentially categorised as dorsal versus plantar incision approaches. Beyond this the commonest technical variation described as influencing the outcome of surgery involves burying and anchoring transacted nerve into soft tissue such as muscle.
How can Morton?s neuroma be prevented? Do not wear tight shoes or high-heeled shoes for prolonged periods. Do wear shoes with a wide toe box so that your toes are not squeezed or cramped. Do wear athletic footwear with enough padding to cushion the balls of the feet when exercising or participating in sports.