A prosthetic ankle assembly including an astragalar component with an upper articular surface that forms part of an ankle joint prosthesis and a lower surface with a shape adapted to engage an upper face of an astragalus. An astragalocalcanean rod is positioned in an astragalocalcanean channel extending from the lower face of the calcaneus to the upper surface of the astragalus. A first end of the astragalocalcanean rod is engage with the lower surface of the astragalar component and a second end of the astragalocalcanean rod is engaged with a lower region of the calcaneus. A distance between the second end of the astragalocalcanean rod is adjustable relative to the lower surface of the astragalar component to adjustably compress the calcaneus against the astragalus.