Accuracy of CT for Measuring Femoral Neck Anteversion in Children With Developmental Dislocation of the Hip Verified Using 3D Printing Technology [post]

Zhencun Cai, Chengzhe Piao, Tianyu Zhang, Lianyong Li, Liangbi Xiang
2021 unpublished
Background: Accurate femoral neck anteversion angle (FNA) measurement is of great significance in the diagnosis and treatment of developmental dysplasia of the hip (DDH) in children. The FNA measurement still remains a controversy. We aimed to verify the accuracy of our CT method by 3D printing technology , and to evaluate its clinical value. Methods: Sixty-eight children with unilateral DDH were enrolled, and their FNA was measured using 2D-CT and 3D-CT, respectively, by three observers. This
more » ... ee observers. This procedure was repeated 3 months later. The above measurement outcomes were then compared with the results in the 3D-printed femur (3D-PF) model. The FNA in the 3D-PF model was measured by three observers collectively through electronic angle instrument. Results: The primary measurement of FNA at the affected hips by 2D-CT was 44.0±6.1, 49.5±8.9 and 52.8±7.9 degrees, respectively. On the 3D-CT, it was 47.6±5.4, 49.3±6.8 and 48.6±6.2 degrees. Three months later, the FNA on 2D-CT was 49.3±10.5, 42.8±7.4 and 45.1±9.3 degrees, and it was 48.0±6.5, 48.9±7.2 and 49.0±5.7 degrees on 3D-CT, respectively. The FNA in the 3D-PF model at the affected and unaffected hips was 48.5±6.6 and 36.9±13.1 degrees. There were significant differences between 2D-CT and 3D-PF measurements, but no significant difference was found between 3D-CT and 3D-PF measurements. The results by 2D-CT showed significant differences among groups and between the groups. However, the results by 3D-CT had no significant differences among groups or between the groups. Conclusion: The results of our study showed that 3D-CT is a more precise, and reproducible method for FNA measurement in DDH. The FNA at the affected hips is 11.6 degree larger than the unaffected in DDH children aged 3-8 years.
doi:10.21203/rs.3.rs-358038/v1 fatcat:pbxfg7npffhcvn3wsm5yrgnomq