There is a shallow learning curve with TELD (transforaminal endoscopic lumbar discectomy). The aim of this study is to assess the safety and efficacy of TELD assisted by electromagnetic navigation for treating lumbar disc herniation (LDH).

Inclusion Criteria:

1. age≥18 and ≤80 years;
2. typical clinical symptoms and consistent imaging evidence of mono-radiculopathy LDH; or single level LSS combined with disc herniation
3. recalcitrant pain despite proper conservative therapy (including analgesics, NSAIDs, corticoids infusion under CT guidance and physical therapy) for at least 3 months before surgery and/or neurological deficit in the territory of the irritated nerve root
4. VAS pain ≥ 6/10
5. Absence of significant instability;

Exclusion Criteria:

1. serious underlying disease or mental illnesses
2. severe central stenosis, cauda equina syndrome, spinal instability, active infection, and serious calcified fragments
3. previous lumbar treatment with spinal surgery, ozone intervention, or radiofrequency ablation
4. unwilling or unable to participate in treatment and complete follow-up
5. Multi-level disc pathology
6. MRC paresis <4/5
7. Pregnancy
8. participation in another clinical trial

20 consecutive patients, group A undergoing TELD with electromagnetic navigation system vs. group B undergoing TELD with X-ray fluoroscopy (gold standard). Parameters: gender, age, body mass index, neurological examination, comorbidities (diabetes, AHT, depression, smoking, work status, other joint problems), recurrence of disc herniation, follow-up time, pain evaluation on the day before surgery (numerical rating scale), herniation level, type of herniation (disc protrusion, disc prolapsed, disc extrusion or sequestered disc), duration of preoperative back pain/leg pain, use of analgesics (type and duration), preoperative Roland-Morris disability questionnaire, preoperative Oswestry Disability Index.