The Fixateur Interne (F.I.) is a new device developed by W. Dick and F. Magerl for the internal fixation of the thoracolumbar spine. This is a completely new system since it does not act as a four point bending system like long rod instrumentation but it is a two point fixation system and it is stable in flexion by itself. Segmental stabilization is attained in the best way by it. The device consists of two pairs of Schanz screws, short connecting threaded rods and hinges. Instrumentation is quite simple: from a posterior approach long Schanz screws are driven into the bodies in transpedicular way above and below the injured level. Reduction is made by manual action, rod-connection, reclination and distraction, stabilization by nut fixation. Its main advantages are excellent reposition-possibilities, good fixation, all kinds of decompression-procedures are possible beside it, simple technique, immobilization of only two segments, good for all kinds of injuries between Th 8 and S 1, postoperative external fixation is not necessary and early rehabilitation is possible. According to our early experiences and the data of literature it is worth while to turn to F. I. if proper supply can be assured.