MTP Synovitis (Capsulitis)
This condition is a sharp or aching pain in the ball of the foot that is most often centered beneath the base of the second toe. This pain is an indication that the bone at the base of the toe, called the proximal phalanx, is beginning to separate from the long bone of the foot, called the metatarsal.
MTP Synovitis is caused by increased stress on the metatarsophalangeal joint at the base of the toe, which causes inflammation and degeneration of the ligaments and tissues that hold the joint together. Increased stress is typically caused by activities that generate an excessive load on the ball of the foot, such as climbing ladders, squatting, or using an elliptical trainer or stairclimbing machine. Harmful stress can also be caused by high-heeled shoes, rheumatoid arthritis, or by physical problems such as a bunion, an abnormally high arch or abnormally long second toe.
Symptoms typically include pain in the ball of the foot, most commonly beneath the second toe. Pain increases when standing (especially when standing on the toes), when barefoot, when walking on a hard surface, and during activity. Symptoms may also include a second toe that is beginning to shift out of alignment to the left or to the right, or a second toe that lifts off the ground during standing. In advanced cases, the toe may have shifted completely out of position and crossed over the top of the big toe. This is called 'crossover toe.'
Treatment options commonly include taping, splinting, and icing of the problem joint. In some cases, a walking boot or a cast and crutches may be needed. If those methods are not successful, surgery may be needed.