Preoperative Neck Disability Severity Limits Extent of Postoperative Improvement Following Cervical Spine Procedures

Abstract

Objective: Our study aims to evaluate the impact of severity of preoperative Neck Disability Index (NDI) on postoperative patient-reported outcome measures (PROMs). Methods: A retrospective review of primary, elective, single or multilevel anterior cervical discectomy and fusion or cervical disc arthroplasty procedures between 2013 and 2019 was performed. Visual analogue scale (VAS) neck and arm, NDI, 12-item Short Form physical and mental composite score (SF-12 PCS and MCS), Patient-Reported Outcome Measurement Information System physical function, and 9-item Patient Health Questionnaire (PHQ-9) were collected preoperatively and postoperatively. Patients were categorized by preoperative NDI: none-to-mild disability ( < 30); moderate disability ( ≥ 30 to < 50); severe disability ( ≥ 50 to < 70); complete disability ( ≥ 70). The impact of preoperative NDI on PROM scores and minimum clinically important difference (MCID) achievement rates were evaluated. Results: The cohort included 74 patients with none-to-mild disability, 95 moderate, 76 severe, and 17 with complete disability. Patients with greater preoperative disability demonstrated significantly different scores for NDI, VAS neck, SF-12 MCS, and PHQ-9 at all timepoints (p < 0.001). Patients with more severe disability demonstrated different magnitudes of improvement for NDI (all p < 0.001), VAS neck (p ≤ 0.009), VAS arm (p = 0.025), and PHQ-9 (p ≤ 0.011). The effect of preoperative severity on MCID achievement was demonstrated for NDI and for PHQ-9 (p ≤ 0.007). Conclusion:Patients with severe neck disability demonstrated differences in pain, disability, physical and mental health. MCID achievement also differed by preoperative symptoms severity. Patients with more severe neck disability may be limited to the degree of improvement in quality of life but perceive them as significant changes.

Neck Disability Index as a Prognostic Factor for Outcomes Following Cervical Disc Replacement

“…A prior study by Cha et al (2022) reported poor NDI to correlate with poor mental health both preoperatively and postoperatively in patients undergoing cervical spine surgery; however, this study did not assess the rate of improvement in mental health in patients with inferior disability scores. 22 Between groups, patients in the MD cohort reported significantly superior SF-12 MCS scores preoperatively and up to 6 months postoperatively, similar to the study performed by Cha et al (2021). The frequency of MCID achievement in SF-12 MCS was not significantly different between groups.…”

“…31 Similarly, a study, including patients who had undergone either ACDF or CDR, by Cha et al (2021) reported patients with greater preoperative NDI scores to experience significantly greater degrees of improvement in raw NDI score and greater rate of MCID achievement in NDI, VAS neck, and VAS arm when compared with patients with lower preoperative disability. 32 However, Cha et al (2021) noted that while a greater degree of improvement in NDI was observed, the severely disabled group continued to report inferior raw NDI scores along with inferior physical function, mental health, and pain scores at all postoperative periods compared with the less disabled cohorts. 32 With these prior findings in mind, we hypothesized that patients undergoing CDR with a greater preoperative disability may report inferior raw scores postoperatively when compared with less disabled patients, but may see a greater frequency of clinically meaningful improvement in disability.…”

“…32 However, Cha et al (2021) noted that while a greater degree of improvement in NDI was observed, the severely disabled group continued to report inferior raw NDI scores along with inferior physical function, mental health, and pain scores at all postoperative periods compared with the less disabled cohorts. 32 With these prior findings in mind, we hypothesized that patients undergoing CDR with a greater preoperative disability may report inferior raw scores postoperatively when compared with less disabled patients, but may see a greater frequency of clinically meaningful improvement in disability.…”

“…Prior studies of preoperative disability, measured by either NDI or ODI for cervical or lumbar procedures, respectively, have demonstrated greater potential for improvement in patients who reported greater disability before the intervention. [19][20][21]31,32 Saberi and Isfahani (2008) reported patients suffering from lumbar disk herniation with higher preoperative ODI had a greater degree of improvement following lumbar discectomy than those with lower preoperative scores. 19 Coury et al (2022) demonstrated higher ODI before surgery for complex spinal deformity to be associated with higher rates of MCID achievement after the intervention.…”

“…Cha et al (2021) previously reported greater rates of MCID achievement in patients with greater levels of preoperative disability, in contrast with this current data; however, similar findings regarding differences in raw scores were noted. 32…”