A method of positioning an arcuate tool against inner annular walls of the disc that particularly facilitates reaching posterior and postero-lateral portions of the inner annulus of the disc by arthroscopy. An elongated, arcuate and shape memory tool such as a catheter is positioned against the inner annular wall of the disc, and particularly on the posterior and postero-lateral portions of the inner annulus of the disc, which are portions of the disc to be treated. The deformable and arcuate tool retains its predetermined arcuate shape when no pressure or force is applied to the tool.