Vektor CoCr is the shaping with rounded contours guarantees a closed cement layer on the surface of the entire prosthesis stem and leads to a patricidal filling of the intertrochanter region. Vektor CoCr is a physiologically and biomechanically becoming prosthesis system for cemented stem anchorage. The implant is offered in five size graduations and two dysplasia versions with a largely straight proximal stem and it can be applied left and right. The arched lateral contour maintain on the proximal stem makes certain the rotational stability. The load is interesting structures of the Shenton's arch. Femural neck corticalis and the calcar femoris are conserved. Same is the case for the hard spongiosa near the corticalis, which is filled in with cement and stiffened. Thus, that there is a distal shift of force transmission and the stress protection atrophy of the proximal femur is reduced.