The intramedullary fixation device for use in fixing the relative position between a tubular bone and an adjoining bone has, according to the present invention, an intramedullary nail that is inserted into the medullary canal of the tubular bone whose position is to be fixed, an elongated blade for insertion into the adjoining bone whose position is to be fixed relative to that of the tubular bone, a coupling element for fixing and locking the relative position of the nail and blade after their insertion, and a means for locating and positioning within the bones to-be-treated the nail and blade. Furthermore, the blade has a cross-sectional shape that is configured in consideration of the geometry of the bone into which the blade is to-be-placed and so as to enhance the ability of the blade to stabilize the bone, and these elements are configured so that they do not have to be decouple during the process of inserting the nail and blade.
