Abstract: The device disclosed in the present invention for functional restoration of an extremity comprises an artificial hip joint, an artificial knee joint and artificial femoral diaphysis. The artificial femoral diaphysis is made up of a cylindrical column having a through longitudinal bore, and a rod, both said column and said rod being interlinked telescopically. The cylindrical column is inseparably linked to the artificial knee joint, while the rod is inseparably linked to the artificial hip joint at one of its ends and with the other end is fitted into the bore of the column, said other rod end carrying a threaded sleeve which engages a motion screw rotatably mounted in the column for the rod to travel with respect to the column.