The invention relates to the preparation of an intervertebral space with a trial implant (9), the insertion of an implant (5, 6, 7), the inserters (13, 16), and the method for feeding and inserting the implant (5, 6, 7) by means of an oblique anterior approach. In the novel improved method, the associated instruments (13, 16) for inserting an implant (5, 6, 7) into an intervertebral space, in particular for the lumbar spine at an oblique anterior angle of 45° was developed, the left side of the body being preferred for insertion of the implant (5, 6, 7). Either the implant (5, 6, 7) can be inserted all in one, or first the upper part (5) and lower parts (7) and then the inlay (6) may be inserted. By insertion by means of the left oblique anterior approach at 45°, optimum utilization of the area of the intervertebral space is ensured (footprint), and better retention of the implant is guaranteed by the exact chiselling at an angle of 90° normal to the respective intervertebral surface.
