This tibial implant (2) comprises a tibial base (3) intended to be fastened to a resected proximal end of a tibia of a patient, the tibial base (3) comprising a medial bearing portion (7) and a lateral bearing portion (8) and a tibial insert (4) shaped to be mounted on the tibial base (3), the tibial insert (4) comprising a medial insert portion (17) including a concave medial bearing surface (18) intended to cooperate with a medial condyle of a femoral component or of a femur, and a lateral insert portion (19) including a concave lateral bearing surface (21) intended to cooperate with a lateral condyle of the femoral component or of the femur. The lateral insert portion (19) has, at its postero-lateral edge (24), an insert notch (26) for the passage of the tendon of the popliteus, and/or the lateral bearing portion (8) has, at its postero-lateral edge (12), a base notch (13) for the passage of the tendon of the popliteus.
