Background: After around two years of trial use and complication evaluations at a proctoring institution, OLIF51 (Oblique Lateral Interbody Fusion for L5/S1) was released to the public in April 2020 in Japan.
Objective: Using the proctoring facility's preliminary registry data analysis, confirm the safety and effectiveness of OLIF51.
Methods: After receiving consent from each institution's ethical review board, anonymized and aggregated data for 114 instances that were registered in the OLIF51 proctoring facility database were examined.
Results: Out of the 114 instances that were registered between July 2019 and November 2021 (43 males and 71 females, with an average age of 71.2±10.6 years), 53 cases were diagnosed with L5 spondylolisthesis (including lytic spondylolisthesis), 47 cases with adult spinal deformity, and 3 cases with lumbar disc degeneration. The average surgical time was 250.8 minutes (in a combined anterior-posterior surgery: position adjustments were included), and the average blood loss was 301.6 milliliters. In 33.0% of instances, intraoperative neuromonitoring was employed. The most common grafts used in interbody cages were autologous iliac bone alone (43.9%), which was supplemented with DBM (Demineralized Bone Matrix) (36.5%); the usage of allografts and synthetic bone made up 8.7% and 2.9% of the total, respectively. The intervertebral angle with a cage inserted improved from an average of 10.9° prior to surgery to roughly 17° after surgery, along with disc height. These postoperative parameters demonstrated a considerable improvement that was maintained for up to two years following surgery. Assessments of activities of daily living (ADL) and quality of life (QOL) following surgery revealed notable gains above preoperative levels. Bone fusion rates were 12.7% at one year and 44.9% after two years, as shown by bridging between the upper and lower vertebrae on X-ray CT. With an incidence rate of 4.39%, complications happened in 5 cases (4 occurrences of hemorrhage and 1 case of screw loosening). There was no noticeable bleeding, however there were vascular injuries such as hemorrhage connected to the abnormal path of the median sacral vein and venous pinhole damage from instrument contact. There were no signs of neurological deficit-related problems, such as retrograde ejaculation.
Conclusion: The application of OLIF51 in 114 instances demonstrated reasonably satisfactory postoperative outcomes with no major problems reported, based on the preliminary database at the OLIF51 proctoring facility.