If you sometimes feel that you are “walking on a marble,” and you have persistent pain in the ball of your foot, you may have a condition called Morton’s neuroma. A neuroma is a benign tumor of a nerve. Morton’s neuroma is not actually a tumor, but a thickening of the tissue that surrounds the digital nerve leading to the toes. Morton’s neuroma occurs as the nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. Morton’s neuroma most frequently develops between the third and fourth toes, usually in response to irritation, trauma or excessive pressure. The incidence of Morton’s neuroma is 8 to 10 times greater in women than in men.
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.
Patients will feel pain that worsens with walking, particularly when walking in shoes with thin soles or high heels. Also, anything that squeezes the metatarsal heads together may aggravate symptoms, such as narrow shoes. A patient may feel the need to remove the shoe and rub the foot to soothe the pain.
You should visit a doctor or podiatrist (foot doctor) if you have pain or tingling that does not stop. Your health care provider will examine your feet and will apply pressure on the spaces between the bones of the toes to determine the location of the foot pain. The doctor may order X-rays to rule out other conditions associated with foot pain, such as a stress fracture or arthritis. X-rays alone will not show whether or not a neuroma is present, so an ultrasound scan or magnetic resonance imaging (MRI) test may be done to confirm the diagnosis. A diagnostic procedure called an electromyography is sometimes used to rule out nerve conditions that may cause symptoms like those of associated with Morton?s neuroma.
Non Surgical Treatment
Treaments may include wearing wider shoes to reduce the squeezing force on the foot. Adding a specially made padding to shoes to offload the pressure on the ball of the foot (called a metatarsal dome) Addressing the foot and lower limb biomechanics. This involves looking at foot stability and if needed prescribing an orthotic device to correct your foot position. Anesthetic & Cortisone injections. This is done when the above treatments are insufficient. The trauma is sometimes so great that conservative treatment cannot control the inflammation or cause of the pain. A series of injections are performed to control the inflammation or to temporarily settle the nerve. An ultrasound and cortisone injection can be prescribed by your podiatrist.
If symptoms do not respond to any of the above measures then surgery may be suggested. This involves a short 30 minute operation to either remove tissue to take pressure off the nerve or to remove the nerve causing the pain. The surgery can be done as a day case but it will be two or three weeks before you can be fully active on your feet. There may be some lingering numbness afterwards if the nerve is removed. But surgery is successful in around 80% of cases. There is a small risk of complications such as infection and thickening of the skin on the soles of the feet.