Fig. 2

a Posteoanterior X-ray picture, b sagittal, and c axial MR images showed L5/S1 disc herniation with high iliac crest in a 44-year-old man. The tip of the puncture needle was in the posterior one third of intervertebral space on d lateral C-arm view and beyond the medial border of pedicle on e posteoanterior C-arm view. During the procedure of PTES, a 7.5-mm working cannula was advanced over the guiding rod to the vicinity of the sequestrated fragment on f lateral and g posteoanterior C-arm view after the enlargement of the foramen. i Endoscopic picture showed that the nerve root was exposed for complete decompression after removal of h sequestrated disc fragments, which was confirmed on j sagittal and k axial MR images 1 week after operation. After 2 years follow-up, l sagittal and m axial MR images showed no recurrent herniation