Methods: This retrospective study enrolled patients with severe lumbar canal stenosis who underwent biportal endoscopic “Z” technique decompression between 2021 and 2023. Patients with any clinical or radiological signs of spondylolisthesis were excluded. The resection of the ligamentum flavum was classified into piecemeal resection, one-piece “butterfly” resection, and the novel variant “two-wings” or two-piece resection. Several demographic and clinical statistical variables were collected, with a specific focus on surgical time, postoperative complications, and clinical outcomes. Results: Ninety lumbar decompression surgeries were performed on 70 patients. The patients were divided into the butterfly group (en bloc) with 27 levels, “two-wings” group with 35 levels, and “piecemeal” group with 28 levels. No significant differences in demographics or clinical variables were found among the three groups. However, piecemeal resection was associated with a higher incidence of dural tears and a longer surgical time (p<0.05). In contrast, en bloc resection, particularly in the two-wing group, demonstrated the best surgical times without an increase in complication rates. Conclusions The results revealed that removing the ligamentum flavum en bloc (either in two pieces or one) may reduce the surgical time and incidence of dural tears. Randomized and prospective studies are warranted to establish definitive conclusions.

Methods: This retrospective study enrolled patients with severe lumbar canal stenosis who underwent biportal endoscopic “Z” technique decompression between 2021 and 2023. Patients with any clinical or radiological signs of spondylolisthesis were excluded. The resection of the ligamentum flavum was classified into piecemeal resection, one-piece “butterfly” resection, and the novel variant “two-wings” or two-piece resection. Several demographic and clinical statistical variables were collected, with a specific focus on surgical time, postoperative complications, and clinical outcomes. Results: Ninety lumbar decompression surgeries were performed on 70 patients. The patients were divided into the butterfly group (en bloc) with 27 levels, “two-wings” group with 35 levels, and “piecemeal” group with 28 levels. No significant differences in demographics or clinical variables were found among the three groups. However, piecemeal resection was associated with a higher incidence of dural tears and a longer surgical time (p<0.05). In contrast, en bloc resection, particularly in the two-wing group, demonstrated the best surgical times without an increase in complication rates. Conclusions The results revealed that removing the ligamentum flavum en bloc (either in two pieces or one) may reduce the surgical time and incidence of dural tears. Randomized and prospective studies are warranted to establish definitive conclusions.

Methods: This retrospective study enrolled patients with severe lumbar canal stenosis who underwent biportal endoscopic “Z” technique decompression between 2021 and 2023. Patients with any clinical or radiological signs of spondylolisthesis were excluded. The resection of the ligamentum flavum was classified into piecemeal resection, one-piece “butterfly” resection, and the novel variant “two-wings” or two-piece resection. Several demographic and clinical statistical variables were collected, with a specific focus on surgical time, postoperative complications, and clinical outcomes. Results: Ninety lumbar decompression surgeries were performed on 70 patients. The patients were divided into the butterfly group (en bloc) with 27 levels, “two-wings” group with 35 levels, and “piecemeal” group with 28 levels. No significant differences in demographics or clinical variables were found among the three groups. However, piecemeal resection was associated with a higher incidence of dural tears and a longer surgical time (p<0.05). In contrast, en bloc resection, particularly in the two-wing group, demonstrated the best surgical times without an increase in complication rates. Conclusions The results revealed that removing the ligamentum flavum en bloc (either in two pieces or one) may reduce the surgical time and incidence of dural tears. Randomized and prospective studies are warranted to establish definitive conclusions.

This report presents a case of a patient with a large synovial cyst treated using a biportal endoscopic ipsilateral approach. Synovial cysts are dilatations of synovial sheaths arising from the zygapophyseal joint capsule. Surgical resection of the cyst and decompression of the neural structures remain the preferred treatment. The size of a cyst is directly proportional to the strength of its attachment to the capsule and dura; thus, larger cysts exhibit a broader area of adhesion between the cyst wall and the dura. The contralateral endoscopic approach has gained popularity for small cysts due to its ability to preserve the facet joint and facilitate cyst dissection. However, larger cysts, which adhere more firmly to the dura, pose greater technical challenges for dissection via the contralateral route. We describe a case of a large synovial cyst successfully treated with a biportal endoscopic ipsilateral approach. A 62-year-old man presented with left leg radicular pain (L5 root) and severe neurogenic intermittent claudication. Preoperative magnetic resonance imaging revealed a large left L4–5 synovial cyst causing severe central canal stenosis. Complete resection was achieved using the ipsilateral unilateral biportal endoscopic technique. Postoperative magnetic resonance imaging confirmed adequate decompression without complications. The patient’s symptoms resolved immediately after surgery, and no spinal instability was observed 1 year postoperatively. The endoscopic biportal ipsilateral approach represents a viable and effective option for the treatment of synovial cysts, particularly those of large size.