An implantable orthopedic device for the knee, comprising at least two parts which are not connected to each other, which are capable of being positioned opposite each other, and each of which comprise a surface engaging with that of the other part in the operative position, one part is attachable onto the tibia side, and the other part is attachable on the femur side such that, according to the invention, both of said parts are to be attached onto the sides and outer side of the knee joint, one part being mobile relative to the other along a plane that is parallel to the vertical median plane of the knee joint, and onto one of the inner or outer sides of the knee.
