Abstract: This is a new bone spacer with semispherical projecting parts and/or teeth suitable for fitting and engaging in cavities specifically prepared on the surface of the vertebrae so as to prevent the displacement of said spacer, and containing at least one channel placing the side facing towards the operator during its insertion in communication with the two opposite, superior and inferior surfaces facing the vertebrae. Plates are also provided for coupling superiorly and inferiorly to the spacer, complete with ribs and/or teeth.

Abstract: The multilumen catheter (2) is provided at one end with a needle system (9, 9′) formed by two or more single-lumen needles which are provided with respective discharge openings (110, 111) and which, via their longitudinal lumina (10, 11), are connected to corresponding lumina (3, 4) of the catheter for separate release of a tracer fluid for external image diagnostics systems and therapeutic fluids, for example DNA plasmids. The needles may be both straight or both helical or one of these needles may be straight and the other needle may be helical.