The Association of Preoperative Duration of Symptoms With Clinical Outcomes and Minimal Clinically Important Difference Following Anterior Cervical Discectomy and Fusion

Abstract

This was a retrospective cohort study. The purpose of this study is to examine whether the time duration from symptom onset to operative treatment is associated with postoperative clinical improvement after anterior cervical discectomy and fusion (ACDF). There is a paucity of literature regarding the influence of preoperative symptom duration on patient-reported outcomes (PROs) following ACDF. Patients who underwent primary, single-level ACDF were retrospectively reviewed and stratified according to preoperative symptom duration (<12 and ≥12 mo). Demographic and perioperative characteristics were compared using χ analysis and linear regression. Subgroup mean scores were compared and achievement of minimal clinically important difference (MCID) was assessed for the Neck Disability Index (NDI), Visual Analogue Scale (VAS) neck pain, VAS arm pain, and 12-Item Short-Form Physical Component Score. A total of 109 patients underwent primary, single-level ACDF: 68 had duration of symptoms (DOS) <12 months and 41 had a DOS ≥12 months. When comparing DOS subgroup preoperative PROs, there was no preoperative difference in NDI, VAS arm or neck pain, and 12-Item Short-Form Physical Component Score. In the postoperative period, there were no significant differences in the improvement of PROs throughout the 12-month timepoint. A significantly larger proportion of the <12 months DOS cohort achieved NDI MCID at the 3-month (66.1% vs. 43.8%, P=0.039) and 6-month (76.8% vs. 53.6%, P=0.030) postoperative period. Among the patient subgroups with <12 and ≥12 months DOS, there were no statistically significant differences observed in any of the measured PRO means at any timepoint. When assessing MCID, however, patients with shorter DOS (<12 mo) were observed to attain NDI MCID at the 3- and 6-month timepoints more often than patients with DOS ≥12 months. Our findings suggest that delayed surgical intervention may impair functional recovery to MCID in patients with degenerative cervical disease.