The present invention relates to a knee joint endoprosthesis having a tibial component and a femoral component and a hinge joint for coupling the tibial component and the femoral component so as to be pivotal about a rotational axis, which hinge joint comprises a first joint element and a second joint element coupled therewith so as to be rotatable about the rotational axis, wherein a connecting device is provided having at least one first connecting element and at least one second connecting element for connecting the first joint element to the femoral component, which connecting device defines a connecting position, in which the at least one first connecting element and the at least one second connecting element are engaged in a at least one of non-positive- and positive-locking manner, and an assembly position, in which the first joint element and the femoral component are fully separated from each other.
