The invention relates to a hip joint endoprosthesis system, comprising a medical instrument for extracting an implanted prosthesis stem of a hip joint endoprosthesis from a femur bone of a patient, which medical instrument has a coupling body with a coupling recess for accommodating a coupling cone protruding from the prosthesis stem, wherein the coupling body comprises a coupling base body and a coupling insert which is accommodated in a coupling insert receptacle of the coupling base body and defines the coupling recess.