Comparison Between Three- and Four-Level Anterior Cervical Discectomy and Fusion: Patient-Reported and Radiographic Outcomes.

Objective: We compared the long-term clinical and radiographic outcomes after 3- and 4-level anterior cervical discectomy and fusion (ACDF) in a retrospective cohort study.

Methods: Patients who had undergone primary 3- or 4-level ACDF were retrospectively identified. The demographic data and patient-reported outcome measures (PROMs) were collected through a review of the medical records. PROM surveys were administered preoperatively for baseline measurements and at 1 year postoperatively. The surveys included the Neck Disability Index, 12-item short-form physical component summary, 12-item short-form mental component summary, and visual analog scale (VAS) scores for neck and arm pain. The cervical sagittal alignment parameters included C2-C7 lordosis, segmental lordosis, the sagittal vertical axis (SVA), and the T1 slope. Multivariate regression models were used to compare the changes in the PROMs and radiographic measurements over time between 3- and 4-level ACDF. Correlation coefficients were calculated to compare the delta scores for the PROMs and radiographic measurements.

Results: The VAS scores for neck and arm pain had significantly improved from baseline in both cohorts. Only the 3-level group showed significant improvements perioperatively in the Neck Disability Index and 12-item short-form physical component summary. No significant differences were found in the improvement in clinical outcomes between the 2 groups. The pooled results demonstrated a significant negative correlation between the perioperative changes in segmental lordosis and VAS scores for arm pain. A significant negative correlation was also found between the perioperative changes in the SVA and 12-item short-form mental component summary and VAS scores for neck pain. C2-C7 lordosis significantly increased postoperatively only in the 3-level ACDF group.

Conclusions: Patients undergoing both 3- and 4-level ACDF experienced significant clinical improvement without significant differences between the 2 groups. The radiographic measures of segmental lordosis and SVA also correlated with the changes in clinical outcomes.