Patient selection method

Inclusion criteria include the following: (a) unilateral or bilateral lower extremity pain with or without low back pain; (b) nerve root symptoms such as abnormal sensations in the lower extremities, positive straight leg elevation test, and positive reinforcement test; (c) diagnosis of single-segment lumbar intervertebral disc herniation by computed tomography (CT) and magnetic resonance imaging (MRI) (Fig. ​(Fig.3c–f);3c–f); (d) failed of standard conservative treatment for 3 months; and (e) PELD operation and follow-up for more than 3 months.

The patient was a 32-year-old male (group L) and had a protrusion in the posterior left portion of the L5/S1 interverbral discs. a MRI revealed a left L5/S1 interverbral disc protrusion in the sagittal section. b In the cross-section, it revealed a protrusion in the posterior left portion of the L5/S1 interverbral discs, which compressed the left S1 nerve root. c, d Three months after the operation, in the sagittal section and the transverse section, it revealed no significant protrusion in the L5/S1 interverbral discs, and the nerve roots were not compressed

Exclusion criteria include the following: (a) vertebral instability and spinal stenosis; (b) cauda equina syndrome; (c) lumbar spine fracture, tumor, or active infection in the surgical area; and (d) other systemic diseases that do not allow the patient to tolerate surgery.