The invention relates to an osteosynthesis implant (1) for adapting the shape and the working volume of a ribcage with a view to the implantation of an artificial heart in said ribcage, characterized in that it comprises the following elements: —a main part (10) which has a shape and dimensions that can be adapted to the shape and the dimensions of the rib cage, —attaching elements (20) for attaching the main part to the ribcage, wherein said attaching elements (20) are rigidly attached to the main part (10), and—a protection (30) for the artificial heart, attached to the main part (10).
