Interdigital neuroma (Morton?s Neuroma) of the foot includes common, paroxysmal, neuralgia affecting the web spaces of the toes. It involves entrapment neuropathy (nerve compression) of the common digital nerve below and between the metatarsal heads, typically between the third and the fourth metatarsal heads. The pain is most commonly felt between the third and fourth toes but can also occur in the area between the second and third toes.
Although the exact cause for this condition is unclear, a number of factors can contribute to the formation of a neuroma. Biomechanical deformities, such as a high-arched foot or a flat foot, can lead to the formation of a neuroma. These foot types bring on instability around the toe joints, leading to the development of the condition. Trauma can cause damage to the nerve, resulting in inflammation or swelling of the nerve. Improper footwear that causes the toes to be squeezed together is problematic. Avoid high-heeled shoes higher than two inches. Shoes at this height can increase pressure on the forefoot area. Repeated stress, common to many occupations, can create or aggravate a neuroma.
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.
The doctor will ask about your symptoms and medical history. A physical exam will be done. Initial diagnosis of Morton's neuroma is based on your description of the type and location of pain and discomfort in the foot. The diagnosis will be confirmed by a physical exam of the foot, including checking for mechanical abnormalities in the foot, squeezing the side of the foot, which will usually cause pain when Morton's neuroma is present. Examination of your shoes to check for excess wear in parts of the shoe, check to see whether the shoes are too tight. Imaging tests evaluate the foot and surrounding structures. This may be done with X-ray, MRI scan, Ultrasound. Injections of local anesthetic can also be used for diagnosis.
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.
Operative treatment of Morton?s neuroma should be entertained only after failure of nonoperative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritate/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although in rare instances, an incision on the sole (plantar) aspect of the foot maybe used. An incision on the sole of the foot works very well, unless an excessive scar forms in which case it can be problematic. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament and freeing the nerve of local scar tissue. This may also be beneficial.