Clinical and Radiographic Outcomes Following Lateral Lumbar Interbody Fusion in Patients Greater Than 75 Years Old

Introduction: With the globally aging population and increasing demand for fusion surgery, there is a growing need to identify optimal surgical techniques for elderly patients with degenerative spine disease. Therefore, we evaluate perioperative complications, clinical outcomes, and long-term sagittal alignment in patients over the age of 75 following lateral lumbar interbody fusion (LLIF) for degenerative lumbar disease.

Methods: This a single-center, retrospective case series of consecutive patients over 75 years who underwent single or multi-level LLIF from 2017-2022. Complications were stratified into major vs. minor based on criteria defined by the ACS-NSQIP. Postoperative transient neuropraxia or permanent neurologic deficit were documented. PROs included the ODI, VAS back, and VAS leg pain. Radiographic parameters included the SVA, SL (stratified by level), LL, PI-LL mismatch, sacral slope, and pelvic tilt. Cage subsidence was defined as migration >2-mm. Clinical and radiographic outcomes were assessed using paired t-tests and multivariable regression.

Results: Fifty-two LLIF patients ≥ 75 years old (mean 78.6; range 75-87) treating 87 levels were included, with a mean (SD) follow-up of 12.2 (6.3) months. All PROs significantly improved at latest follow-up, including the ODI (-14.5±17.5 points), VAS back (-2.2±3.8 points), and VAS leg pain (-3.3±3.9 points, all p< 0.001). There were no intraoperative complications. Postoperatively, there were three major and three minor complications. One patient experienced persistent thigh paresthesias that did not resolve by 90 days postoperatively. No femoral nerve injuries occurred. Patients experienced significant improvements in SVA (-1±2.7mm), SL (+5.9±4.1°), LL (5.3±9.8°), and PI-LL mismatch (-2.9±6.4°, all p< 0.001). Cage subsidence was observed in 8 (16%) cases.

Conclusion : This series demonstrates safe clinical outcomes and stable long-term radiographic outcomes in elderly patients undergoing LLIF for degenerative lumbar spine disease.