Age-Related Differences in Clinical and Surgical Outcomes Following Oblique Lateral Interbody Fusion: A Retrospective Cohort Study.

Introduction: We compared patient outcomes following oblique lateral interbody fusion (OLIF) for degenerative lumbar spine conditions among different age groups. Materials and Methods: This retrospective cohort study included patients between January 2018 and July 2020. Patients were stratified into three groups based on age at the time of surgery (<65 years, 65 to <75 years, and ≥ 75 years). Preoperative and postoperative patient-reported outcome measures were assessed, including visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol-5 Dimension (EQ-5D). Postoperative orthopedic events, including screw loosening, cage subsidence, and revision surgery, were recorded. All patients' survival status were followed until March 2023. Cox-proportional hazard models were conducted to examine the associations of age groups with postoperative orthopedic events and all-cause mortality. Results: A total of 170 patients were analyzed (n=77, 68, and 25 for age <65 years, 65 to <75 years, and ≥ 75 years, respectively). VAS, ODI, and EQ-5D significantly improved after OLIF in all groups (all p<0.001). There were no significant differences in rates of postoperative screw loosening (p=0.702), cage subsidence (p=0.095), and revision surgery (p=0.265) across the three age groups. After a median follow up of 4.06 years, the three groups had no significant difference in orthopedic event-free survival (log-rank p=0.302). The findings were consistent after multivariate adjustment. Conclusion: OLIF is a safe and effective surgical option for elderly patients with degenerative lumbar spine conditions.