The Effect of the Preoperative Severity of Neck Pain on Patient-Reported Outcome Measures and Minimum Clinically Important Difference Achievement After Anterior Cervical Discectomy and Fusion

Objective: To compare patient-reported outcome measure (PROM) scores and minimum clinically important difference (MCID) achievement rates among patients undergoing single-level anterior cervical discectomy and fusion (ACDF) in patients with varying severity of preoperative visual analog scale (VAS) neck score.

Methods: Patients with ACDF were grouped: severity of preoperative VAS neck score ≤8 or >8. Demographic/perioperative variables and PROMs (Patient-Reported Outcomes Measurement Information System Physical Function [PROMIS PF] score, 12-Item Short Form [SF-12] Mental Component Score [MCS], VAS neck/arm score, and Neck Disability Index [NDI]) were collected preoperatively/postoperatively. MCID attainment comparison by grouping was evaluated using χ² analysis.

Results: A total of 137 patients were included (103 VAS neck preoperative score ≤8; 34 VAS neck preoperative score >8). The VAS neck preoperative score ≤8 cohort did not improve: 6 weeks PROMIS-PF score, 6 weeks SF-12 Physical Component Score [PCS], 12 weeks/1 year/2 years SF-12 MCS, 2 years VAS neck score, and 1 years/2 years VAS arm score (P ≤ 0.015, all). VAS neck preoperative score >8 did not improve: 6 weeks/12 weeks/2 years PROMIS-PF score, all time points SF-12 PCS, 6 weeks/12 weeks/1 year/2 years SF-12 MCS, and 2 years VAS arm score (P ≤ 0.013, all). VAS neck preoperative score >8 had inferior PROMIS-PF scores all time points except 1 year (P ≤ 0.036, all), lower SF-12 PCS 6 weeks/6 months (P ≤ 0.043, both), inferior SF-12 MCS at preoperative to 6 months (P ≤ 006, all), higher VAS neck score from preoperative to 6 months (P ≤ 0.018), higher VAS arm score preoperative/12 weeks/6 months (P ≤ 0.020, all), and higher NDI at preoperative/12 weeks/6 months (P ≤ 0.030, all). MCID attainment rates for VAS neck preoperative score >8 were greater for NDI 2 years (P = 0.040), lower for PROMIS-PF score 2 years, and overall (P = 0.018), lower for SF-12 MCS 12 weeks (P = 0.046), lower for VAS neck score 12 weeks to 1 year and overall (P ≤ 0.032, all), and lower for VAS arm score 6 weeks/1 year (P ≤ 0.030, both).

Conclusions: Patients with single-level ACDF presenting with greater baseline neck pain showed poorer physical function/pain/disability/mental health at preoperative/intermediate postoperative time points, but had comparable long-term PROMs by 2 years. MCID attainment was lower among patients with greater preoperative neck pain; MCID among the VAS neck score >8 cohort were only significantly inferior for neck pain.