Dr. Morton was the first to describe a nerve condition between the 3rd and 4th toes. This deformity involves the squeezing of the common digital nerve. The reason this condition is greatest between the 3rd and 4th toes is due to its position as the most distant branch of the medial plantar nerve. The nerve travels under the intermetatarsal ligament (a ligament which holds the ball of the foot together). When toes move in an upward direction, the nerve is stretched under this ligament.
In cases of a flat foot or excessive motion creating a low arch, this distant nerve becomes stretched. The tissue which surrounds the nerve becomes inflamed. This inflammation then turns into fibrous tissue which squeezes the nerve. This type of trauma is repeated over and over again. With every step, the nerve is squeezed and injured. This is combined with a number of other factors including loss of fat pad, high heeled shoes, bone spurs, bony abnormalities, toe deformities, and compression between the 2 metatarsals.
The symptoms include pain, burning, tingling, numbness, and cramping. The longer the neuroma is present with the abnormal factors in place, the worse the condition becomes. Treatment consists of anti-inflammatory medication, cortisone injections, physical therapy, orthotics, alcohol injections, and removal. X/rays can assist in its diagnosis. Although, X/rays are not a definitive method to confirm the diagnosis. MRI is another tool used in its diagnosis with a greater ability to confirm the diagnosis. Never the less, most diagnoses are made through the initial office evaluation.
