Influence of Predominant Neck versus Arm Pain on Clinical Outcomes in Cervical Disc Replacement

Objective: We aim to compare the postoperative clinical outcomes, through patient-reported outcome measures (PROMs) and minimum clinically important difference (MCID), in patients undergoing cervical disc replacement (CDR) with preoperative predominant neck pain (pNP) or arm pain (pAP).

Methods: Patients undergoing primary CDR were separated into pNP or pAP cohorts. Demographic, perioperative characteristics, PROMs at preoperative and postoperative time points, and MCID were compared using inferential statistics. Assessed PROMs included Patient-Reported Outcome Measurement Information System-Physical Function (PROMIS-PF), 12-Item Short Form Physical/Mental Component Score (SF-12 PCS/MCS), visual analog scale (VAS) neck, VAS arm, and Neck Disability Index.

Results: There were a total of 84 patients, with 54 patients in the pNP cohort. The pNP cohort showed significant postoperative improvement in all PROMs, except for 6-week and 1-year SF-12 PCS, 1-year SF-12 MCS, and 6-month VAS arm score (P ≤ 0.023, all). The pAP cohort showed significant postoperative improvement in all PROMs, apart from 6-month to 1-year SF-12 PCS, and all SF-12 MCS (P ≤ 0.041, all). Greater MCID achievement rates were found in the pNP cohort for SF-12 MCS (P = 0.030). The pAP cohort had higher MCID achievement rates in VAS arm score and Neck Disability Index (P ≤ 0.046, all).

Conclusions: Independent of predominant pain location, patients reported improved physical function, pain, and disability outcomes. Patients with pNP had higher MCID achievement rates in mental function. Patients with pAP had higher rates of MCID achievement in arm pain and disability outcomes. Considering the predominant location of preoperative pain may be helpful in managing expectations for patients undergoing CDR.