BACKGROUND

Herniated lumbar disc is a common cause of lumbosacral pain. Endoscopic interlaminar lumbar discectomy (ILD) is a well-established technique that provided comparable results to micro-discectomy. The aim of the study is to describe the learning curve of endoscopic ILD and explore measures that could improve effectiveness and decrease blood loss and operative time with accumulation of reasonable experience.

METHODS

This retrospective cohort study included 65 patients presenting with symptomatic herniated lumbar disc who underwent endoscopic ILD. Patients were divided into two groups: Group I (standard technique) and Group II (modified technique). Collected data included patients' age, gender, preoperative manifestations, visual analog score (VAS) for pain, Oswestry Disability Index (ODI), disc level, operative time, intraoperative blood loss, complications, and follow-up data at 1, 6, and 12 months postoperatively. Primary outcomes included total operative time, amount of intraoperative blood loss, and post-operative improvement in pain. Secondary outcomes included intraoperative complications, rate of conversion to open surgery, and recurrence.

RESULTS

Post-operative VAS and ODI improved significantly in both groups. Mean total surgical time and intraoperative blood loss were significantly lower in Group II compared to Group I ( < 0.001). The learning curves for operative time and intraoperative blood loss were shallow in Group I, and almost flattened in Group II. Complications were recorded in only three cases, and no symptomatic recurrences were reported.

CONCLUSION

The learning curve of endoscopic ILD was shallow with standard technique, indicating difficulties in mastering the procedure. The proposed modified technique helped reaching the required level of proficiency in the early phase of the curve, providing a significant reduction in operative time and blood loss, with comparable effectiveness and safety as the standard technique.