# Correlation between Iliac Tilt and traditional sagittal parameters in adolescents

## TL;DR

The study introduces Iliac Tilt (IT) as a new, reliable parameter for assessing spinal balance in adolescents, showing strong correlations with traditional parameters and stability across developmental stages.

## Contribution

The study systematically validates Iliac Tilt (IT) as a novel and reliable parameter for assessing sagittal spinal balance in adolescents.

## Key findings

- Iliac Tilt (IT) is significantly negatively correlated with Pelvic Tilt (PT) and significantly positively correlated with Pubic-Sacral Angle (PSA).
- IT remains highly stable across different Risser stages of skeletal development, unlike PSA and T1 Slope-Pelvic Incidence (T1SPI).

## Abstract

This study aims to systematically validate the reliability and applicability of Iliac Tilt (IT) as a parameter for sagittal balance assessment, explore its relationship with traditional parameters such as Pelvic Tilt (PT) and Pubic-Sacral Angle (PSA), and analyze its performance across different stages of skeletal development.

A retrospective study was conducted with 118 healthy pediatric participants. Full-length sagittal radiographs were obtained using the advanced EOS imaging system, and relevant sagittal plane parameters were measured using standardized methods. Participants were grouped based on Risser staging, and statistical analyses, including one-way analysis of variance (ANOVA), Pearson correlation analysis, and linear regression, were performed.

Iliac Tilt (IT) was significantly negatively correlated with Pelvic Tilt (PT) (r = -0.761, p < 0.001) and significantly positively correlated with Pubic-Sacral Angle (PSA) (r = 0.814, p < 0.001). Linear regression analysis revealed that IT was a significant predictor of both PT and PSA, with R² values of 0.736 and 0.717, respectively. Additionally, across different Risser stages, IT demonstrated high stability, while PSA and T1 Slope-Pelvic Incidence (T1SPI) showed significant changes with staging.

As a novel parameter, Iliac Tilt (IT) demonstrates high reliability and broad applicability in reflecting posterior pelvic tilt and sagittal spinal balance. Compared to traditional parameters, IT offers a simpler measurement process, making it suitable for complex cases with limited imaging quality. It provides an efficient evaluation tool for clinical and research applications.

Introduction of a Novel Parameter: This study systematically validates Iliac Tilt (IT) as a new and reliable parameter for assessing sagittal spinal balance in adolescents, demonstrating its broad applicability.

Strong Correlations Identified: IT shows a significant negative correlation with Pelvic Tilt (PT) (r = -0.761) and a significant positive correlation with Pubic-Sacral Angle (PSA) (r = 0.814), highlighting its effectiveness in reflecting pelvic and spinal alignment.

Stability Across Developmental Stages: IT remains highly stable across different Risser stages of skeletal development, unlike traditional parameters such as PSA and T1 Slope-Pelvic Incidence (T1SPI), which vary significantly with skeletal maturity.

Clinical Advantages: Compared to traditional sagittal parameters, IT offers a simpler and more reliable measurement process by requiring only unilateral iliac imaging, making it suitable for complex cases with limited imaging quality or special anatomical structures.

Foundation for Future Research: The findings establish IT as a valuable tool for clinical and research applications in spinal health assessment, recommending further studies to explore its applicability in diverse age groups and pathological conditions.