Does Baseline Severity of Arm Pain Influence Outcomes Following Single-Level Anterior Cervical Discectomy and Fusion?

ABSTRACT

STUDY DESIGN: Retrospective cohort. PURPOSE: To assess preoperative arm pain severity influence on postoperative patient-reported outcomes measures (PROMs) and minimal clinically important difference (MCID) achievement following single-level anterior cervical discectomy and fusion (ACDF). OVERVIEW OF LITERATURE There is evidence that preoperative symptom severity can affect postoperative outcomes. Few have evaluated this association between preoperative arm pain severity and postoperative PROMs and MCID achievement following ACDF. METHODS: Individuals undergoing single-level ACDF were identified. Patients were grouped by preoperative Visual Analog Scale (VAS) arm ≤8 vs. >8. PROMs collected preoperatively and postoperatively included VAS-arm/VAS-neck/Neck Disability Index (NDI)/12-item Short Form (SF-12) Physical Composite Score (PCS)/SF-12 mental composite score (MCS)/Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF). Demographics, PROMs, and MCID rates were compared between cohorts. RESULTS: A total of 128 patients were included. The VAS arm ≤8 cohort significantly improved for all PROMs excepting VAS arm at 1-year/2-years, SF-12 MCS at 12-weeks/1-year/2-years, and SF-12 PCS/PROMIS-PF at 6-weeks, only (p ≤0.021, all). The VAS arm >8 cohort significantly improved for VAS neck at all timepoints, VAS arm from 6-weeks to 1-year, NDI from 6-weeks to 6-months, and SF-12 MCS/PROMIS-PF at 6-months (p ≤0.038, all). Postoperatively, the VAS arm >8 cohort had higher VAS-neck (6 weeks/6 months), VAS-arm (12 weeks/6 months), NDI (6 weeks/6 months), lower SF-12 MCS (6 weeks/6 months), SF-12 PCS (6 months), and PROMISPF (12 weeks/6 months) (p ≤0.038, all). MCID achievement rates were higher among the VAS arm >8 cohort for the VAS-arm at 6-weeks/12-weeks/1-year/overall and NDI at 2 years (p ≤0.038, all). CONCLUSIONS: Significance in PROM score differences between VAS arm ≤8 vs. >8 generally dissipated at the 1-year and 2-year timepoint, although higher preoperative arm pain patients suffered from worse pain, disability, and mental/physical function scores. Furthermore, clinically meaningful rates of improvement were similar throughout the vast majority of timepoints for all PROMs studied.