Bunion Surgery is used to treat an abnormal bone growth known as a bunion. A bunion is found on the big toe and can form due to stress on the foot or other reasons. There are different methods that can be used to treat the bunion surgically. For instance, the doctor might perform surgery to straighten the big toe, remove tissue around the joint of the toe, realign bones within the toe, or fuse bones together. The method depends on the patient's condition.