Disposable modular spacer device (1) of the articulation of a knee comprising a tibial element (2 2 2 ) constrainable to an end of the tibial bone in proximity of the articulation of the knee and comprising a lower surface (7) and an upper surface (16 16 16 ) provided with a radius of curvature R2 and a femoral element (4 4 4 ) comprising an inner surface (14) constrainable to an end of the femoral bone at the articulation of the knee and an outer convex surface (15 15 15 ) provided with a radius of curvature R1 and in contact with the upper surface (16 16 16 ) of the tibial element (2 2 2 ) the tibial element (2 2 2') and the femoral element (4 4 4 ) having various dimensions or sizes the tibial element (2 2 2 ) being configured so as to be coupled with any size of the femoral element (4 4 4 ) to adapt the dimensions of the modular spacer device (1) with the dimensions of the bone ends to which it should be connected.
