An implantable device is described, comprising an implant (12), wherein the implant comprises at least one opening (22), at least one anchoring element (14) for fixing the implant to at least one bone, wherein the respective anchoring element comprises a shank (20) and a head (18) and wherein at least a part of the shank can be guided through the respective opening while the head can be seated in the respective opening, and a locking mechanism with a fixation element (16) and a radially deformable annular element (26) that can be pressed against the head of the anchoring element by actuation of the fixation element, in order to fix the head in the opening of the implant. The opening of the implant has a recess (28) having a support surface (24) for the head of the anchoring element.