A patient-specific instrument for durable resurfacing hip replacement device comprises a head-neck-area receiving inner portion, a top edge portion, an outer portion, one or more distal-head-neck-hole guiding pins, a femoral-shaft-hole guiding pin, and a vertical groove. The head-neck-area receiving inner portion is contoured to fit over a portion of head, neck, and upper shaft body of the femur. The one or more distal-head-neck-hole guiding pins are installed on the top edge portion, so as to work as a first reference line showing a first direction of a long nail portion of the durable resurfacing hip replacement device. The femoral-shaft-hole guiding pin is installed on the outer portion, so as to work as a second reference line showing a second direction of a lag screw portion of the durable resurfacing hip replacement device. The vertical groove is provided on the outer portion and aligned in parallel to the femoral-shaft-hole guiding pin.
