The common causes of paravalvular bone protrusion are congenital flat foot, paravalvular bone nodule and so on. 1. Congenital flat foot: it is due to congenital deformity of the foot, abnormal development of the foot bones, caused by the arch of the foot becomes low, or even show a flat state, when the foot walks on the ground, resulting in a mild foot outward roll, or even the protruding of the paravalvular bone. 2. Paravalvular bone nodule: if the patient has long-term walking, extrusion, wear and tear and other conditions lead to local edema, the formation of aseptic inflammation, leading to the paravalvular bone hyperplasia and hypertrophy, protrusion. In addition, trauma to the ankle joint, causing strain to the tendon of the foot paravalvular bone, leading to local edema and protrusion of the paravalvular bone. When the patient found that the paravalvular bone protrudes, should go to the hospital in time to consult the examination, under the guidance of professional doctors, according to the cause of targeted treatment.