This paper presents a hybrid structure/trajectory constraint, that uses output camera poses of a model-based tracker, for object localization with SLAM algorithm. This constraint takes into account the structure information given by a CAD model while relying on the formalism of trajectory constraints. It has the advantages to be compact in memory and to accelerate the SLAM optimization process. The accuracy and robustness of the resulting localization as well as the memory and time gains are evaluated on synthetic and real data. Videos are available as supplementary material.