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Final Program


Final Program

915 - Association Between Putative Neck Strength, C2 Slope, Sagittal Vertical Alignment and Patient Reported Outcomes in Multi- Level Posterior Cervical Fusion- A Multi Center Analysis

Friday, February 28, 2025
5:00 PM - 6:30 PM MST
Objectives: Investigate the relationship between pre-operative extension capacity and clinical and radiographic outcomes in patients undergoing a three or more level posterior cervical fusion with a C7 caudal level. 

Design: Multi-center retrospective study. Pre-operative extension capacity was measured as the change in the C2 slope (neutral vs. extension cervical x-ray films). We also collected C2 slope, cervical Sagittal Vertical Axis (cSVA), Oswestry Disability Index (ODI) and Pain Visual Analog Scale (VAS) . Receiver operating characteristic (ROC) curve analysis was performed, and the Youden index was calculated to determine the matching C2 slope cutoff value according to the established radiographic parameter.

Results: 324 patients were included in this study, with a mean age 62.6 ± 12 years, 57% female, and mean BMI of 28.7. Of these patients, 57% were non-smokers, 32.1% former-smokers and 10.9% current-smokers. The Δ C2 slope was negatively correlated with SVA (r=-0.58) and VAS and ODI. These relationships were observed throughout all pre-and postop intervals. C2 slope had a cutoff point of 15.1° according to a SVA of 40mm (AUC 0.671, sensitivity 0.58, specificity 0.85). The Δ C2 slope improved over follow up (preop vs 24m postop: 7.5° vs. 11.1°, p< 0.05), as well as the other parameters. SVA improved, 44.2 mm vs.31.1 mm, pain VAS decreased 5.01 vs 3.2, and ODI decreased 46.1 vs 27.3, p< 0.05 (preop vs 24m post, p< 0.05).

Conclusions:

Neck strength, in terms of the ΔC2 slope, was positively correlated with SVA and negatively with VAS and ODI scores in patients who underwent a three or more level posterior cervical fusion. The results of this study support the hypothesis that greater extension capacity is associated with better clinical, and patient reported outcomes postoperatively. Additionally, pre- and postop C2 slope is a useful clinical prognostic factor in multilevel posterior cervical fusion.