Perioperative safety and short-term clinical outcomes of spinal fusion in patients aged 85 years and older: a 5-year single-center retrospective study

Objective: To evaluate the perioperative safety and short-term clinical outcomes of spinal fusion in patients aged 85 years and older, comparing traumatic and degenerative indications.Methods: We retrospectively reviewed 28 consecutive patients aged ≥ 85 years who underwent spinal fusion (transforaminal, posterior, or anterior lumbar interbody fusion) at a single high-volume center between January 2020 and December 2024, out of 432 patients aged ≥ 85 years undergoing spinal surgery.Complications were classified as major or minor and outcomes as satisfactory or unsatisfactory, assessed at discharge or the first outpatient visit.Categorical associations used the Fisher exact test.Results: The mean age was 87.3 years.Degenerative disease was present in 16 patients (57.1%) and traumatic injury in 12 (42.9%).Satisfactory outcomes were achieved in 21 of 28 patients (75.0%).Overall complications occurred in 12 patients (42.9%): major in 3 (10.7%)and minor in 9 (32.1%).No significant association was found between major complications and anesthesia type (P = 0.24) or comorbidities (all P ≥ 0.90).The traumatic group had a lower complication rate than the degenerative group (25.0% vs. 56.3%,P = 0.14).The mean hospital stay was 15.8 days.Conclusion: Spinal fusion in carefully selected patients aged ≥ 85 years was associated with a 10.7% major complication rate and a 75.0%satisfactory outcome rate.Outcomes were perioperative and short-term; long-term outcomes were not evaluated.With only 3 major complication events, the study was underpowered to confirm or exclude associations with comorbidities; these findings are preliminary.