A device for intrabody extension with screws working in traction. A first extendedsection (1) receives a second telescopic section (2). Each of these sectionsincludes connection means (61), (62) from the organism to a first end point (11),(21), and is linked to a pin (3) containing at least one threading to a second endpoint (12) and (22). Rotation of the pin (3) controlled by means (4) causes relativemovement of the two sections (1) and (2). Thus, the pin (3) is mounted between twoend points (12) and (22) which get closer when the device extends, and the lengthof the loaded pin (7) decreases when the device extends and the length of the loadedpin (7) works only in traction. The device according to the invention is specificallydesigned for making screws for bone extension and growth prostheses.
