Modular joint

The present invention concerns a modular joint. In a particular embodiment thereof, it concerns a prosthetic knee joint or component(s) therefor. Basic implantable joint is adapted such that addable component(s) thereto can be added to the basic joint without removal of the joint from the site to which it can be initially implanted to provide a modular joint. Other modular features to a basic implantable joint are provided as well. The modular joint can be, for example, that of the knee and include a basic, implantable femoral component, with the addable component(s) able to be added inter-condylarly, which, for example, can include an insertable rotation device with a swingable, depending male type part; intramedullary spike and/or posterior stabilizing stop.