The introduction of endoscopic spine surgery has led to a paradigm shift in the treatment of spinal disorders. In particular, biportal endoscopic surgery has gained traction for its wider visual field and improved the maneuverability of instruments, familiar anatomy, and costeffectiveness. In this study, we describe our en bloc removal of the ligamentum flavum using a “butterfly” technique. This approach had several advantages: (1) The flavum serves as a protective barrier for the dura during drilling. (2) There is less epidural bleeding, which provides (3) better visualization. (4) In an inadvertent durotomy, this usually occurs later in the procedure, which is more manageable than the early stages of decompression. Biportal decompression for spinal stenosis can be performed using an en bloc ligamentum flavum removal technique that is safe, reproducible, and efficient. A systematic approach will help early adopters overcome the steep learning curve.

Single-position lateral interbody fusion surgery has gained traction over the years because of reduced surgical time and improved operating theater workflow. With the introduction of robotics in spine surgery, surgeons can place pedicle screws with a high degree of accuracy and efficiency; moreover, the robot allows us to localize the disk space and perform endplate preparation accurately with minimal radiation. In this study, we discuss the potential synergistic benefits of integrating robotic-assisted spine surgery and singleposition prone lateral surgery. We share our technique and provide the operative nuances of using the Mazor X Stealth Edition system (Medtronic, Minneapolis, MN, USA). We highlighted the potential synergistic benefits of integrating both the prone lateral and robotic-assisted surgical techniques, including the challenges encountered. This approach is not meant to replace other techniques or be used in all patients. Instead, it adds to our arsenal for managing spine fusion.

STUDY DESIGN: A retrospective study of radiographic parameters of patients who underwent lumbar spinal pedicle screw insertion.PURPOSE: The optimal length of pedicle screws is often determined by the lateral radiograph during minimally invasive surgery (MIS). Compared with open techniques, measuring the precise length of screws or assessing the cortical breach is challenging. This study aims to ascertain the optimal pedicle screw lengths on intraoperative lateral radiographs for L1–L5.OVERVIEW OF LITERATURE: Research has revealed that optimal pedicle screw length is essential to optimize fixation, especially in osteoporotic patients; however, it must be balanced against unintentional breach of the anterior cortex, risking injury to adjacent neurovascular structures as demonstrated by case reports.METHODS: We reviewed intra- and postoperative computed tomography scans of 225 patients who underwent lumbar pedicle screw insertion to ascertain which of the inserted screws were ‘optimal screws.’ The corresponding lengths of these screws were analyzed on postoperative lateral radiographs to ascertain the ideal position that a screw should attain (expressed as a percentage of the entire vertebral body length).RESULTS: We reviewed 880 screws of which 771 were optimal screws. We noted a decreasing trend in average optimal percentages of insertion into the vertebral body for pedicle screws going from L1 (average=87.60%) to L5 (average=78.87%). The subgroup analysis revealed that there was an increasing percentage of screws directed in a straight trajectory from L1 to L5, compared to a medially directed trajectory.CONCLUSIONS: During MIS pedicle screw fixation, this study recommends that pedicle screws should not exceed 85% of the vertebral body length on the lateral view for L1, 80% for L2–L4, and 75% for L5; this will minimize the risk of anterior cortical breach yet maximize pedicle screw purchase for fixation stability.
Humans ; Lumbar Vertebrae ; Minimally Invasive Surgical Procedures ; Pedicle Screws ; Radiography ; Retrospective Studies

Methods: Retrospectively, patients who underwent TLIF and LLIF for various degenerative conditions were shortlisted. Each of their fused levels with the cage in situ was analyzed independently, and the preoperative, postoperative, and follow-up disc height measurements were compared between the groups. In addition, the total disc height loss since surgery was calculated at final follow-up and was compared between the groups. Results: Forty-six patients (age, 64.1±8.9 years) with 70 cage levels, 35 in each group, were selected. Age, sex, construct length, preoperative disc height, cage height, and immediate postoperative disc height were similar between the groups. By 3 months, disc height of the TLIF group was significantly less and continued to decrease over time, unlike in the LLIF group. By 1 year, the TLIF group demonstrated greater disc height loss (2.30±1.3 mm) than the LLIF group (0.89±1.1 mm). However, none of the patients in either group had any symptomatic complications throughout follow-up. Conclusions Although our study highlights the biomechanical advantage of LLIF over TLIF in maintaining disc height, none of the patients in our cohort had symptomatic complications or implant-related failures. Hence, TLIF, as it incorporates posterior decompression, remains a safe and reliable technique despite the potential for greater disc height loss.