[Feasibility of enlarging the ventral space by using a drill under spinal endoscopy in the treatment of severe free lumbar disc herniation].

Objective: To evaluate the clinical efficacy of spinal endoscopy in the treatment of severe free lumbar disc herniation and explore the feasibility and application of microscopic drills to expand ventral space.

Methods: Thirty patients with severe free lumbar intervertebral disc herniation treated by spinal endoscopic technique from April 2019 to March 2021 were collected, including 19 males and 11 females;aged from 19 to 76 years with an average of (44.03±16.92) years old. All patients had a single segmental lesion with prolapse of the nucleus pulposus. Among them, there were 3 cases on L, 3 cases on L, 15 cases on L, and 9 cases on LS. During operation, posterior bone of vertebral body and pedicle notch were removed by a drill under the endoscope to enlarge the ventral space. And the free nucleus pulposus was exposed and completely removed. The intraoperative blood loss, operation time, hospital stay and postoperative neurological complications were recorded, and Japanese Orthopaedic Association (JOA) score, Oswestry Disability Index (ODI) and visual analogue scale (VAS) were compared before operation, 2 days, 3 months and 1 year after operation, and Macnab standard was used to evaluate clinical efficacy.

Results: All operations were successful and the free nucleus pulposus was completely removed. Pain in the lower back and legs was significantly relieved on the day after operation. Two patients experienced transient pain and numbness in lower limbs after operation, and no serious nerve injury complications occurred. ODI and VAS at each time point after surgery were significantly lower than those before surgery (<0.01), and JOA score was significantly higher than before surgery (<0.01). The excellent and good rates of Macnab were 66.67% (20/30), 83.33% (25/30) and 90.00% (27/30) on 2 days, 3 months and 1 year after operation, respectively.

Conclusion: For severe free lumbar intervertebral disc herniation, using of a drill under endoscope to expand the ventral space can smoothly remove the free nucleus pulposus and avoid nerve damage.