# How Can We Prevent Postoperative Kyphosis in Cervical Laminoplasty?

## TL;DR

This study identifies uppermost facet disturbance as a key risk factor for postoperative kyphosis after cervical laminoplasty, suggesting its preservation could help prevent this complication.

## Contribution

The study introduces uppermost facet disturbance as a novel independent risk factor for postoperative kyphosis in cervical laminoplasty.

## Key findings

- Loss of cervical lordosis was significantly associated with uppermost facet disturbance, C3 involvement, and lamina fractures.
- Multivariate analysis confirmed uppermost facet disturbance as the only independent predictor of postoperative kyphotic change.
- C3 involvement and lamina fractures lost significance after adjusting for facet disturbance, indicating collinearity.

## Abstract

Background and Objectives: This study aimed to evaluate changes in cervical sagittal alignment after open-door laminoplasty and identify any specific preventable risk factors associated with postoperative kyphotic deformity. Materials and Methods: We retrospectively reviewed patients who underwent open-door laminoplasty for degenerative cervical stenosis between 2018 and 2021. Radiological assessment included pre- and postoperative C2–C7 Cobb angles, cervical alignment categories (lordosis, straight, sigmoid, kyphosis), and K-line status. Early postoperative CT scans were analyzed for lamina fractures and facet joint disturbances. Clinical and demographic data, as well as surgical variables such as C3 involvement, were also recorded. Results: Among 78 patients with available pre- and postoperative MRI images (mean age 56.5 ± 11.2 years; 42.3% female), the mean cervical lordosis decreased significantly from 8.78 ± 13.75° to 6.49 ± 13.82° (p = 0.024). Loss of lordosis was strongly associated with facet disturbance at the cranial-most operated level (p = 0.036), inclusion of C3 in laminoplasty (p = 0.031), and cranial-most lamina fractures (p = 0.004) in univariate analyses. However, in the multivariate logistic regression model, only the uppermost facet disturbance was identified as the independent risk factor for postoperative kyphotic change (OR 4.62, p = 0.039). C3 involvement and lamina fracture lost significance after adjustment, likely reflecting collinearity with facet injury at the cranial level. Other demographic or technical variables were not found to be statistically significant predictors. Conclusions: Postoperative sagittal alignment after laminoplasty is influenced by surgical complications at the cranial levels. A novel predictor—uppermost facet disturbance—emerged as a significant contributor to loss of lordosis. Preservation of these structures represents a practical strategy to reduce postoperative kyphotic drift. Prospective multicenter validation of the present study’s findings is warranted.