A neuroma is an enlarged, benign growth of nerve and scar tissue, most commonly between the third and fourth toes. Repetitive trauma (chronic irritation) is the most common mechanism of injury. This causes the ends of the nerves to get trapped and pinched between the metatarsal heads during the push-off phase of walking. If one's foot pronates excessively during the push-off phase, this may produce metatarsal 'shear' whereby the bones pinch and rub the nerve to the point where it develops a neuroma. Also, hammer or claw toes can cause a stretching of the interdigital nerves which causes it rub on the ligaments, thereby creating a Neuroma. Acute onset, such as stepping on a sharp object or falling on the ball of the foot, is also possible.
Presents as neuralgia pain or numbness on the bottom of the foot, but out towards the toes. It starts on the ball of the foot and radiates out toward the 3rd and 4th toes (the big toe is the 1st toe) Pain can be burning or sharp and agonizing. Exacerbated by walking on hard surfaces or wearing high heels or tight shoes and relieved by rest, removal of shoes, sitting down an massaging the foot. Pain can usually be recreated by squeezing the forefoot together. This puts pressure on the nerve and increases symptoms.
Treatment can be either conservative or surgical. Daily cold whirlpool and ultrasound can help decrease inflammation and pain. It is important to have the mechanics of the feet addressed and any lack of movement in the joints of the foot should be addressed and corrected. A metatarsal pad, placed on the heel-side of metatarsal heads, can often alleviate the pain. Orthotics can also be helpful. Surgical treatment is carried out when conservative measures fail and involves resection of the enlarged section of the nerve.
Angelo Podiatry Associates, P.A.
3162 Appaloosa Cir San Angelo, TX 76901