Comparison of Clinical Effectiveness of Full Endoscopic Lumbar Discectomy (FELD) and Microdiscectomy (MD) in Patients With Lumbar Disc Herniation

The goal of this clinical trial is to compare the clinical effectiveness of Full Endoscopic Lumbar Discectomy (FELD) and Microdiscectomy (MD) in patients aged 18-85 with single-level lumbar disc herniation who have not undergone prior lumbar surgery. This study also aims to perform a radiological analysis of MRI scans before and after treatment to optimize patient selection and surgical strategies. The main questions it aims to answer are: * Does FELD provide superior early postoperative pain relief (measured by VAS) compared to MD? * Does FELD offer better functional recovery (measured by COMI and ODI scores) postoperatively compared to MD? * Can radiological analysis of pre- and post-operative MRI images help optimize patient qualification and guide surgical strategies? Researchers will compare patients undergoing FELD to those undergoing MD to see if endoscopic techniques result in faster recovery and lower early postoperative pain while maintaining similar long-term outcomes. The study will also analyze how MRI findings correlate with clinical outcomes to refine operative decision-making. Participants will: * Undergo either FELD or MD surgery * Complete VAS, COMI, and ODI questionnaires at pre-specified follow-up intervals (1, 3, 6, and 12 months post-surgery) * Have MRI scans 24 hours before surgery, 24 hours after surgery, and at each follow-up to assess disc recurrence, residual pathology, and to optimize surgical strategies.