Morton's neuroma

Morton's neuroma is a painful condition in which the tissue surrounding one of the small nerves between the toes becomes thickened, usually in the space between the third and fourth toes. Squeezing of that irritated nerve produces burning pain under the front of the foot and numbness or tingling that reaches into the toes.

• Burning, stabbing, or shooting pain under the front of the foot, sometimes running out into the toes
• A feeling of standing on a pebble or a fold in your sock
• Numbness, tingling, or cramping in the toes
• Pain that worsens in tight or high-heeled shoes, or with pressure on the ball of the foot
• Usually no visible lump

The exact cause is not known. The most widely accepted explanation is that the nerve is repeatedly squeezed and irritated between the bones of the forefoot, and the tissue around it thickens in response.

Factors linked to Morton's neuroma include:

• Tight, narrow, or high-heeled shoes
• Activities that put repeated pressure on the ball of the foot
• Foot shapes and conditions such as flat feet, high arches, bunions, and hammertoes

It is more common in women and most often appears in adults between about 30 and 60.

The diagnosis is usually made from your symptoms and an examination. The clinician presses between the bones of the forefoot and may squeeze the foot from side to side to bring on the pain.

X-rays help rule out other causes, such as a stress fracture or arthritis. Ultrasound or MRI can confirm a neuroma when the diagnosis is unclear. Sometimes a numbing injection is placed in the area: if the pain goes away, it supports the diagnosis.

Non-surgical treatment is tried first:

• Wider shoes with a roomy toe box and a low heel
• A metatarsal pad or orthotic that spreads the bones and takes pressure off the nerve
• Padding or taping of the forefoot
• Cutting back on activities that bring on the pain
• Anti-inflammatory medication for short-term relief when appropriate
• A steroid injection into the area

If pain continues for several months despite these measures, or keeps returning, surgery may be considered. The surgeon either releases the tight ligament pressing on the nerve or removes the affected section of nerve (neurectomy). Removing the nerve leaves permanent numbness in the skin between the two toes it supplied.

Surgery is usually done as an outpatient procedure. Afterward, most people walk in a stiff-soled surgical shoe, avoid high-impact activity and soaking the foot until the incision has healed, and return gradually to regular shoes over the following weeks.

• Choose shoes with a wide toe box and a low heel, especially for long periods on your feet
• Use cushioned shoes or inserts for high-impact activities
• Limit time in narrow or high-heeled shoes