Overview
A Morton’s neuroma, or interdigital neuroma, is a painful condition which involves a nerve on the plantar aspect (bottom) of the foot. Occasionally a neuroma develops following a bruising injury to the sole of the foot, such as might be caused by jumping onto a rock or other objects, but in general, the origin of the condition is unknown.
Causes
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
Normally, there are no outward signs, such as a lump, because this is not really a tumor. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
Diagnosis
To arrive at a diagnosis, the foot and ankle surgeon will obtain a thorough history of your symptoms and examine your foot. During the physical examination, the doctor attempts to reproduce your symptoms by manipulating your foot. Other tests or imaging studies may be performed. The best time to see your foot and ankle surgeon is early in the development of symptoms. Early diagnosis of a Morton?s neuroma greatly lessens the need for more invasive treatments and may avoid surgery.
Non Surgical Treatment
Treatment depends on the severity of your symptoms. Your doctor will likely recommend trying conservative approaches first. Arch supports and foot pads fit inside your shoe and help reduce pressure on the nerve. These can be purchased over-the-counter, or your doctor may prescribe a custom-made, individually designed shoe insert, molded to fit the exact contours of your foot.
Surgical Treatment
If conservative treatments haven’t helped, your doctor might suggest injections. Some people are helped by the injection of steroids into the painful area. In some cases, surgeons can relieve the pressure on the nerve by cutting nearby structures, such as the ligament that binds together some of the bones in the front of the foot. Surgical removal of the growth may be necessary if other treatments fail to provide pain relief. Although surgery is usually successful, the procedure can result in permanent numbness in the affected toes.