Influence of Preoperative Disability on Outcomes Following Primary Surgical Treatment of Cervical Disc Herniation

Retrospective review.

To evaluate how preoperative disability influences patient-reported outcomes (PROs) following primary surgical intervention for cervical herniated disc.

The effect of baseline disability has been evaluated for various spinal surgeries, but not specifically for primary cervical herniated disc.

A prospectively maintained single surgeon database was retrospectively reviewed to identify patients who underwent primary cervical spine surgery for herniated nucleus pulposus. Demographics, perioperative data, and baseline/postoperative PROs were collected including Neck Disability Index (NDI), Visual Analog Scale-Arm/Neck (VAS-A/N), 12-Item Short Form Mental/Physical Component Scores (SF-12 MCS/PCS), Patient-Reported Outcome Measure Information System-Physical Function (PROMIS-PF), and 9-Item Patient-Health Questionnaire (PHQ-9). Baseline NDI <50/≥50 defined 2 cohorts. ΔPROs were determined at 6-week postoperatively/final follow-up (average 11.8±7.7 postoperative months). Overall rates of minimal clinically important difference (MCID) achievement were determined for each PRO. Perioperative characteristics/demographics/baseline PROs were compared with χ 2 tests (categorical variables)/the Student t test (continuous variables). Intercohort postoperative PROs/ΔPROs/MCID attainment rates were compared with multivariate linear regression (continuous variables)/multivariate logistic regression (categorical variables) accounting for differences in insurance type.

Of 190 patients, there were 69 in the NDI ≥50 group. Patients with NDI ≥50 were more likely to have workers' compensation, or Medicare/Medicaid insurance ( P <0.001) and report worse baseline PROs ( P ≤0.001, all). After controlling for insurance type, NDI ≥50 patients continued to report worse PROs at 6 weeks/final follow-up ( P ≤0.037, all), except PROMIS-PF at 6 weeks postoperatively. NDI ≥50 patients reported greater NDI improvements at 6 weeks ( P =0.007) and final follow-up ( P <0.001). NDI ≥50 patients experienced higher overall MCID achievement rates for PHQ-9/NDI ( P ≤0.015, both).

NDI ≥50 patients reported worse baseline mental/physical health and neck/arm pain and continued to report inferior postoperative outcomes including disability. Despite inferior absolute outcomes, NDI ≥50 patients reported greater improvements/achievement of clinically significant differences in disability through final follow-up. Further, these patients were more likely to experience clinically significant improvements in depressive burden.