The authors report a new technique for percutaneous surgery of thoraco-lumbar discs. It allows nucleotomy or intersomatic grafting. This extra-articular posterolateral approach is performed under fluoroscopic monitoring by using a Kirschner's wire and some specific co-axial tubes. Scanographic polar coordinates are most suitable for valuable locating of thoracic discs and performing of technique. Indications and limits of the method are discussed with preliminary results obtained with the first 19 cases.