A patient-customized surgical instrument used to form a surgical site in a tibia for implantation of an implant into the tibia, and a surgical module using the same. A body part is coupled to the tibia to surround a portion of the tibia. A cutting-member insertion window is formed through a side of the body part to receive a cutting member that is inserted to form a cutting plane of the tibia. A position setting hole is formed through the upper side of the body part to receive and guide a post recess forming member that is used to form a post recess in the tibia. A post of the tibia element is received in the post recess. A surgical site can be accurately and easily formed in a damaged tibia.
