Percutaneous endoscopic transpedicle approach for herniated nucleus pulposus in the lumbar hidden zone

Although endoscopic procedures for lumbar disc diseases have improved greatly, treating migrated disc herniation is still a challenging task. Because of anatomic limitations, a rigid endoscope cannot effectively reach the herniated nucleus pulposus (HNP) in the hidden zone. The purpose of this study was to describe the transpedicle approach for HNP in the hidden zone using the percutaneous endoscopic lumbar discectomy system and to demonstrate the clinical results. Materials and Surgical Technique: Under fluoroscopy, the percutaneous endoscopic lumbar discectomy cannula is placed on the superior articular process, and a trephine with a diameter of 7.3 mm is used to make a bone hole. Through the bone hole, an HNP in the hidden zone can be detected with a rongeur for percutaneous endoscopic lumbar discectomy, the HNP can be removed, and then the decompressed nerve root is verified. We have treated two cases of hidden-zone HNP using the transpedicle approach. In all cases, the HNP was successfully removed, as confirmed by postoperative MRI. Clinical outcomes were acceptable.

The percutaneous endoscopic transpedicle approach is an effective technique for managing HNP in the lumbar hidden zone.