A fixation assembly for securing parts of a sternum has a first section having a first attachment structure for securing the first section to a first sternum part. The fixation assembly includes a second section having a second attachment structure for securing the second section to a second sternum part. A mating arrangement is provided defining a mating direction and a predetermined relative position between the first and second sections in a plane perpendicular to the mating direction. At least one holding member is provided for detachably holding the first and second sections in an abutting relationship in the predetermined relative position. This may be achieved in one variant by simultaneous engagement of the first and second sections substantially along the mating direction.
