Special learning curves and clinical outcomes of full-endoscopic lumbar interbody fusion

Compared to other procedures; there is limited data regarding the learning curve of percutaneous endoscopic lumbar interbody fusion (PE-LIF). Thus, cannot provide a reference for others to understand the difficulties at each surgical step or to improve their skills. This retrospective review included consecutive patients with single-segment lumbar spondylolisthesis or lumbar spinal stenosis who underwent PE-LIF with percutaneous pedicle screw fixation from January 2022-November 2023. The surgical procedure was divided into different steps, and the learning curves of each step were plotted and analyzed. Additionally, initial clinical results were also reported to provide direct experience of the safety, accuracy, and efficiency of PE-LIF. This study included 40 patients, among which 2 patients were lost to follow-up and excluded. As the number of cases increased, the overall operative time and the time taken for each step decreased, but the learning curve differed for each step. All patients had significant postoperative improvements in the visual analog scale score in low-back pain and leg pain, as well as Oswestry Disability Index score, which continued to improve during follow-up. At 1-year follow-up, the modified Macnab outcomes were excellent in 25 patients, good in 12 patients, and fair in 1 patient. Complications occurred in 7.9% of this cohort, including cage retropulsion (n = 1), cage subsidence (n = 1), and dural matter tear (n = 1), whereas no intraoperative neurovascular injury occurred. It is technically feasible and safe to implant an interbody fusion cage device directly through an endoscopic working cannula. The use of endplate handling equipment used in open surgery may speed up the process of endoscopic endplate preparation.