Fig. 1From: Application of a targeted and quantificational foraminoplasty device in percutaneous transforaminal endoscopic discectomy for L5–S1 disc herniation: preliminary clinical outcomesComposition of the ZESSYS device: a 4 graded dual-cannula size. b The thinner cannula containing the Kirschner wire for fixation and the other larger cannula that was used with a trephine for foraminoplastyBack to article page