Fig. 3From: Full-endoscopic foraminoplasty for highly down-migrated lumbar disc herniationSurgical procedures of highly downward-migrated disc removal. a Placement of the endoscopic trephine; b The ventral superior articular process was partially resected using the endoscopic trephine; c The working cannula was directed downward to create an angle of a cranial-to-caudal approach; d The endoscopic forceps were scrupulously used to remove high grade down-migrated massBack to article page