Transforaminal Endoscopic Discectomy for Hard or Calcified Lumbar Disc Herniation: A New Surgical Technique and Clinical Outcomes

Hard or calcified discs are often adherent to surrounding nerve tissue. The whole herniated disc is difficult to remove by pulling part of the hernia mass, which makes obtaining good results through endoscopic treatment difficult. The purpose of this study was to describe the details of the transforaminal endoscopic lumbar discectomy technique for a hard or calcified disc and report the clinical results. From October 2016 to June 2019, 43 consecutive cases diagnosed as hard or calcified lumbar disc herniation at our institution and treated with transforaminal endoscopic discectomy were evaluated. Endoscopic decompression was performed in patients with hard or calcified lumbar disc herniation. The preoperative visual analog scale score for leg pain (mean ± standard deviation) was 7.09 ± 1.74. The score improved to 2.55 ± 1.35 at 1 week postoperatively, 1.88 ± 1.29 at 4 weeks postoperatively, and 1.58 ± 1.0 at 26 weeks postoperatively (P < 0.01 for all). The preoperative Oswestry Disability Index (mean ± standard deviation) was 55.4 ± 23.04, which improved to 30.89 ± 13.64 at 1 week postoperatively, 23.08 ± 11.64 at 4 weeks postoperatively, and 16.42 ± 9.76 at 26 weeks postoperatively (P < 0.01 for all). Two patients developed a dural laceration. Both patients were discharged after several hours of observation. None of the patients had postoperative infection, epidural hematoma, or delayed neurological deterioration. Transforaminal endoscopic discectomy could be an effective treatment method for a selected group of patients with hard or calcified lumbar disc herniation.