C2 Slope as an Independent Predictor of Cervical Lordosis Loss Following Laminoplasty

Postoperative loss of cervical lordosis remains a common and clinically relevant complication following laminoplasty, negatively affecting neck pain, neurological recovery, and long-term sagittal balance. However, reliable and easily applicable preoperative predictors for identifying patients at high risk of cervical lordosis deterioration remain limited. This study aims to investigate whether preoperative C2 slope (C2S) independently predicts cervical lordosis deterioration following laminoplasty.

This retrospective cohort study included 179 patients who underwent cervical laminoplasty for cervical spondylotic myelopathy at our institution between April 2014 and December 2020, with a minimum follow-up of 24 months. Radiological parameters including C2-7 Cobb angle, cervical sagittal vertical axis (cSVA), C7 slope, and C2S are measured preoperatively and at final follow-up. Patients are divided into lordosis deterioration group (> 5°) and control group (≤ 5°). B Between-group comparisons are performed using independent-samples t tests and χ ² tests. Binary logistic regression analysis is conducted to identify independent predictors of postoperative cervical lordosis loss. Receiver operating characteristic (ROC) curve analysis is used to evaluate predictive performance and determine the optimal cutoff value.

The lordosis loss group (n = 55) shows significantly higher preoperative C2S (14.57° ± 3.47° vs. 9.52° ± 7.30°, p < 0.001), lower preoperative Cobb angle (13.01° ± 4.91° vs. 16.1° ± 6.50°, p < 0.001), and greater cSVA (2.58 ± 1.45 cm vs. 2.13 ± 1.42 cm, p = 0.027) compared to controls. The lordosis loss group demonstrates worse postoperative neck pain VAS scores (3.31 ± 1.63 vs. 2.40 ± 1.56, p < 0.001) and slightly lower JOA scores (15.45 ± 1.14 vs. 15.78 ± 1.12, p = 0.037). Multivariate analysis reveals preoperative C2S as the only independent predictor (OR = 1.176, p < 0.001), with 11.49 as cutoff value for C2S.

Elevated preoperative C2S independently predicts postoperative cervical lordosis deterioration. C2S measurement provides a simple, effective tool for identifying high-risk patients and optimizing surgical planning.