Abstract: A tibial implant for knee prosthesis has a tibial socket (1) accepting a tibial plate (2) notably in polyethylene. The tibial socket (1) has a recess (1a) with a shape and section chosen to allow, from the upper face of said socket (1), the engagement, centering and holding in place, with the capability of angular orientation, of an anchoring and/or stabilizing pin with fins (3).