Advanced Age Is Associated With Increased Subsidence, Sagittal Imbalance, and Late-Onset Neck Pain Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the impact of patient age on complication rates, radiographic alignment, and patient-reported outcomes (PROs) following anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ACDF is one of the most common and effective spinal procedures in the United States. However, as a rising number of elderly patients undergo ACDF, age-related differences in outcomes such as subsidence, adjacent segment disease, and PROs remain poorly defined. METHODS: A retrospective review was conducted on 302 patients who underwent ACDF between 2020 and 2022 at a single academic institution. Patients were stratified into 4 age groups: younger than 50, 50-59, 60-69, and 70 years or older. Univariate regression analyses compared cervical sagittal alignment and PROs, while multivariate analyses assessed perioperative characteristics and complications. RESULTS: Compared with the younger-than-50 cohort, patients aged 50-59 exhibited a significantly higher rate of subsidence (29.6% vs. 13.7%, P=0.001). The 60-69 group showed a similar outcome (24.6%, P=0.033) and a significantly longer length of stay (1.34 vs. 0.96 d, P=0.023). Patients aged 70 years or older experienced the most pronounced changes: subsidence occurred in 42.1% (P=0.044), LOS increased to 1.74 days (P=0.001), and SVA increased by an average of 0.83 cm preoperatively, unlike younger cohorts, in whom SVA stabilized. In addition, patients aged 70 years or older reported a significant resurgence of neck pain at 1- and 2-year follow-ups. In contrast, this group also exhibited the greatest improvement in brief resilience scale scores, ultimately reporting the highest resilience at 1 year postoperatively (P=0.0162). CONCLUSIONS: Advanced age is associated with increased subsidence, sagittal imbalance, longer hospitalization, and recurrence of neck pain following ACDF. These findings are important to consider when planning ACDF, particularly in patients aged 70 years or older. Nonetheless, improvements in resilience among older patients highlight their capacity for meaningful recovery. LEVEL OF EVIDENCE: Level III.