The present invention provides a two-part telescopic intramedullary orthopedic device comprising a first section inserted into the medullary cavity of one of the fractured or severed bone ends, and secured thereto, and a second section inserted into the medullary cavity of the other fractured or severed bone end and secured thereto, wherein the first section is telescoped within the internal space of the second section, and wherein one of the sections comprises a ferromagnetic material and the other section is either constructed entirely of a non-magnetic material or comprises a ferromagnetic material, wherein the ferromagnetic section(s) are actuable by an external axially directed magnetic field, such that one section may be caused to move axially (either bidirectional or essentially unidirectional) in relation to the other section. In addition, the invention encompasses a method for changing bone length as well as a method for enhancing bone fracture healing.