Trial neck piece for a joint endoprosthesis

An instrument set for implanting a prosthesis, comprising:

• a reamer configured to remove bone substance, having a head part, and
• a trial neck piece having a fastening region, which can be coupled to the head part of the reamer, and a prosthesis neck region designed to receive a joint ball of the prosthesis, wherein
• a drive head of the reamer is a polygon,
• and wherein the trial neck piece is configured to be plugged with form-fit engagement onto the drive head, and a latching device comprising a plurality of latching stages such that the trial neck piece is attached at different heights on the reamer.

A trial neck piece for a joint endoprosthesis, the trial neck piece comprising:

• a fastening region configured to plug temporarily onto a head part of a shaft body in at least one defined position, a neck region, designed to receive a joint element of a joint endoprosthesis,
• wherein the trial neck piece is configured to be plugged with form-fit engagement onto the head part and locked,
• wherein a latching device is provided which comprises a plurality of latching stages, for different height stages of the trial neck piece on the head part of the shaft body, and
• wherein the fastening region comprises a turn-around and said fastening region has a lower end, and a shoulder which is configured to limit insertion depth.

A trial neck piece for a joint endoprosthesis, the trial neck piece comprising:

• a fastening region configured to plug temporarily onto a head part of a shaft body in at least one defined position, a neck region, designed to receive a joint element of a joint endoprosthesis;
• and
• a pressure spring, which is configured to act on the shaft body, in an inserted configuration, and is configured to press the trial neck piece into a latched position,
• wherein the trial neck piece is configured to be plugged with form-fit engagement onto the head part and locked, and
• wherein a latching device is provided which comprises a plurality of latching stages, for different height stages of the trial neck piece on the head part of the shaft body.