# Comparisons of reference curves for femoral neck geometric parameters between Changsha-Chinese women and women of three ethnic groups in the United States

## TL;DR

This study compares femoral neck geometry in Chinese women and three US ethnic groups, finding differences that may explain variations in hip fracture rates.

## Contribution

The study provides new comparative data on femoral neck geometric parameters across different ethnic groups, highlighting potential explanations for fracture rate disparities.

## Key findings

- Changsha-Chinese women had lower outer diameter, cross-sectional area, and cortical thickness compared to US ethnic groups.
- Changsha-Chinese women showed a higher buckling ratio than US ethnic groups, suggesting increased fracture risk.
- Reference curves for geometric parameters varied significantly by ethnicity and age.

## Abstract

Factors underlying ethnic differences in the incidence of femoral fractures are not fully understood. Reference curves of femoral neck geometric parameters (FNGPS) between Changsha-Chinese women and three United States (US) ethnic groups of women varied by ethnicity, age, and measurement parameters. Further investigations might better explain fracture-rate differences.

Osteoporotic fractures are associated with race, and the risk of femoral neck fractures is associated with FNGPs. We compared age-related FNGPs of Changsha-Chinese women with those of three ethnic groups of women in the US.

Data on 4236 Changsha-Chinese women and non-Hispanic Whites (NHWs), non-Hispanic Blacks (NHBs) and Mexican women (aged 20–91 years) from a laboratory database and research literature, were analyzed to measure their FNGPs: outer diameter (OD), cross-sectional area (CSA), averaged cortical thickness (ACT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), and cross-sectional moment of inertia (CSMI).

The overall means of the OD, ED, SM, and CSMI of the Changsha-Chinese women were significantly lower than those of the NHWs. Their CSA, ACT, SM, and CSMI were significantly lower than that of the NHBs and the age-related reference curves of their CSA, ACT, SM, and CSMI were significantly lower than those of the NHWs, NHBs, and Mexican women. Their OD and ED reference curves were significantly lower than those of the NHWs and NHBs; their OD, CSA, and ACT reference curves were lower than those of the NHWs; and their CSA, ACT, and SM were significantly lower than those of the NHBs. However, their buckling ratio (BR) reference curve was significantly higher than that of the NHWs, NHBs, and Mexican women in the US.

Ethnic differences in the FNGPs of Changsha-Chinese women and US ethnic groups may explain differences in hip-fracture rates among different ethnic groups.

The online version contains supplementary material available at 10.1007/s11657-025-01571-y.