[The surgical repositioning of spondylolisthesis using the internal fixator and a new simple repositioning instrument].

A simple aid for reposition of spondylolisthesis with the Fixateur interne is presented. The modification consists of a metric thread, which is cut in the end of the SCHANZ screw, a fitting butterfly nut and a distance tube. This instrument allows a well-dosed and controlled extension and reposition of the dislocated vertebra in all planes. No other instruments or implants, which may hinder the operation, are necessary. After the reposition the bone graft may be inserted from ventral or from dorsal. The dorsal intercorporal spondylodesis saves time, means a lower trauma for the patient and has the possibility for interfragmental compression.