Painful calluses on the ball of the foot are caused by an abnormal alignment of the metatarsal bones. There are five metatarsal bones in each foot, each consisting of the long bones behind each toe. The metatarsal bone behind the big toe is called the first metatarsal, and so on.
The most common metatarsal surgery is preformed on the first metatarsal for the correction of bunions.
Surgery on the second through fifth metatarsal bones is performed infrequently, and is usually done to treat painful calluses on the bottom of the foot or non-healing ulcers on the ball of the foot. Patients with rheumatoid arthritis may also need metatarsal surgery.