Bone protrusion on the dorsum of the foot may be the form of normal bone structure, or it may be caused by tendon sheath cysts, arch deformities and other factors. 1. Normal bone structure: some people are born with high foot arches, and the tarsometatarsal joints are naturally more elevated. If there are no uncomfortable symptoms, there is no need to deal with it, and it can be improved gradually by choosing shoes that fit the feet. 2. Tendon sheath cysts: Tendon sheath cysts can be created on the back of the foot due to ill-fitting shoes or long-term localized friction. Tendon sheath cysts are generally hard and feel like bones, while the actual cysts may be filled with fluid rather than bone. 3. Arch deformity: If the foot appendage has been injured, and osteophytes appear during the healing period of the fracture, the dorsum of the foot will have a bony protrusion, or due to congenital developmental abnormality caused by high arched feet, which will also cause abnormal arch height. Bone protrusion on the dorsum of the foot may also have other causes, such as primary malignant changes in bone tissue caused by osteosarcoma, osteochondroma, etc., such as the exclusion of physiological factors, it is recommended that the patient go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then under the guidance of the doctor to give targeted treatment or therapy.