Abstract: An implantation system includes a prosthesis shaft, such as a femoral shaft of a hip joint endoprosthesis, for insertion into a cavity of a bone. The prosthesis shaft has a proximal end and a distal end and defines a prosthesis shaft longitudinal axis. A shaft coupling element is formed at the proximal end for coupling to a first handling instrument for inserting the prosthesis shaft into the cavity and/or for extracting it therefrom. The implantation system includes an adapter apparatus with a first adapter device and a second adapter device. The first adapter device is configured to releasably couple to the shaft coupling element in force-locking and/or positive-locking manner in a coupling position. The second adapter device is configured to releasably couple to a second handling instrument. The second adapter device is also arranged or formed on the adapter apparatus laterally offset relative to the first adapter device.