Femoral neck-shaft angle and bone age in 4- to 24-year-olds
The aim of the study was to assess the correlation between femoral neck-shaft angles (NSAs) and skeletal maturity in EOS reconstructions from a large population of children.

Full-body three-dimensional (3D) reconstructions were generated from 1005 children and young adults using the EOS three-dimensional/3D scanner, with images taken during routine clinical practice. The true NSAs were measured and assessed for correlation with individual's chronological age and bone age, based on cervical vertebral morphology. Statistical analysis was performed using Spearman correlation, independent t-test and multiple linear regression. NSAs of older and younger individuals within each bone age group and chronological age were further assessed by t-test.

--NSA values fell from mean 131.89°±6.07° at 4 years old to 128.85°± 4.46° at the age of 16, with only minor decreases thereafter.

--Significantly higher NSAs (3.16° and 4.45°, respectively) were found in those with a bone age advanced or delayed by more two or more stages compared to their peers of the same chronological age.

--Similarly, within most bone age stages, individuals of advanced or delayed chronological age exhibited elevated values (mean difference ranged from 2.9° to 8.9°).

Bone-age assessment was incorporated in the proximal femoral assessment and the identification in children with varied predicted NSAs of the "rapid maturing" and "slow-maturing" sub-categories could be achieved. The earlier oscillation of quicker maturing people can make the NSA stuck in an immature valgus shape.

Source: https://journals.lww.com/jpo-b/Abstract/2021/07000/Femoral_neck_shaft_angle_and_bone_age_in_4__to.5.aspx