IntroductionIn full-endoscopic spine surgery via trans-foraminal approach (FESS-TF), the outside-in method facilitates treatment for various cases; however, the technique is difficult to perform. To facilitate this procedure, we developed a duckbill release technique. In this paper, we aimed to introduce the details of this technique and investigate its effectiveness. Materials and MethodsFifty patients who underwent FESS-TF for intervertebral disc herniation were divided into two groups: the conventional technique and the duckbill release technique groups. The time from the initiation of surgery to exposure of the bone outside the superior articular process was measured in both groups. The visual analog scale (VAS) score for leg pain and the Japanese Orthopaedic Association (JOA) score before and after surgery were compared in terms of clinical outcomes. ResultsNo significant differences were observed between the two groups in terms of patient background. The approach time was 252 ± 86 s in the conventional group, while it was 105 ± 26 s in the duckbill release group, which was significantly shorter (p < 0.001). In terms of clinical outcomes, the two groups did not significantly differ in all endpoints of the VAS score for leg pain or the JOA score. ConclusionsThe duckbill release technique for the outside-in method in FESS-TF could be efficient because it is a simple and time-saving approach.