The invention relates to a method for constructing a patient-specific surgical guide comprising at least one contact element comprising a contact surface intended to match an anatomical structure to be treated in view of implantation of an implant and at least one guiding element for guiding a surgical instrument to treat said anatomical structure, said method comprising:receiving a non-segmented 3D medical image of the anatomical structure of the patientdetermining, in said non-segmented 3D medical image, anatomical references of the patientbased on said anatomical references, positioning an implant model in the non-segmented 3D medical imageadjusting at least one of: a type, a size, a position and an orientation of the implant model with respect to the anatomical structure in the non-segmented 3D medical imagerecording planning data including said adjusted type, size, position and orientation of the implant modelusing a patient-specific surgical guide adapted to carry out implantation of the implant, said patient-specific surgical guide being constructed using the planning data.