an interlocking intramedullary rod assembly for treating a fracture of a bone , said interlocking intramedullary rod assembly comprising : an intramedullary rod comprising a distal section and a proximal section ; a distal interlocking screw ; and a proximal interlocking screw ; wherein said distal section of said intramedullary rod comprises a static distal seat for receiving said distal interlocking screw , and said proximal section of said intramedullary rod comprises a dynamic proximal seat for receiving said proximal interlocking screw ; and further wherein said static distal seat is configured to secure said distal interlocking screw to said intramedullary rod such that said distal interlocking screw cannot move relative to said intramedullary rod , and said dynamic proximal seat is configured to secure said proximal interlocking screw to said interlocking rod such that a first end of said proximal interlocking screw cannot move relative to said intramedullary rod and the second end of said proximal interlocking screw can move relative to said intramedullary rod .