The learning curve of percutaneous endoscopic interlaminar discectomy versus unilateral biportal endoscopic...

This study aimed to quantify and compare the learning curves of percutaneous endoscopic interlaminar discectomy (PEID) and unilateral biportal endoscopic discectomy (UBED) for lumbar disc herniation (LDH), using operative time and clinical outcomes as primary metrics.

This study retrospectively reviewed 158 consecutive patients with lumbar disc herniation (LDH) who underwent endoscopic lumbar discectomy from 2022 to 2024. The patients were categorized into two groups: PEID group (n = 93) and UBED group (n = 65). The learning curve for each technique was evaluated using cumulative sum (CUSUM) analysis. Surgical failure was defined as the occurrence of either complications or a lack of symptom relief. Patient and surgical variables were then compared across the distinct phases of the learning curve.

CUSUM analysis demonstrated distinct learning curves for PEID and UBED, with identified cut-off points at 45 and 31 cases, respectively. Upon reaching the mastery phase, the mean operative time decreased significantly by approximately 17 min for PEID and 18 min for UBED. The surgical failure rate did not differ significantly between the initial and mastery phases in either group. Notably, both techniques resulted in significant postoperative improvements in clinical outcomes, as evidenced by the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores at the final follow-up compared to preoperative baselines.

Both PEID and UBED demonstrated comparable effectiveness and low complication rates in the treatment of LDH. Notably, the learning curve analysis revealed that achieving procedural proficiency required 45 cases for PEID, compared to 31 cases for UBED.