Hip axis length measurement using dual-energy X-ray absorptiometry

Area of Science:

• Orthopedics
• Radiology
• Gerontology

Background:

• Hip axis length (HAL) is a potential independent predictor of hip fracture risk in the United States.
• Modern dual-energy X-ray absorptiometry (DXA) devices offer automated HAL measurements.
• Clinical utility and normative data for HAL in European populations are not well-established.

Purpose of the Study:

• To assess the clinical feasibility of automated hip axis length (HAL) measurement using DXA.
• To establish normal HAL values for French women across different age groups.
• To evaluate the reproducibility and side-to-side consistency of HAL measurements.

Main Methods:

• Feasibility and reproducibility of HAL measurements were assessed in 50-60 French women.
• Short-term reproducibility was determined via two measurements with repositioning.
• Long-term reproducibility was evaluated over six-month intervals.
• Side-to-side differences were analyzed.
• Normative data were collected from 190 women (aged 54±12 years) using single-beam DXA and 50 women (aged 80±5 years) using fan-beam DXA.

Main Results:

• Short-term reproducibility was 1.67%, and long-term reproducibility was 1.5%.
• No significant difference was observed between right and left hip axis length.
• Mean HAL was 10.4±0.6 cm (single-beam) and 11.5±0.7 cm (fan-beam).
• HAL correlated positively with height but not with age or femoral neck bone mineral density.

Conclusions:

• Automated hip axis length (HAL) measurement is feasible and reproducible in clinical practice.
• Normative HAL values for French women were established, differing based on DXA beam type (single vs. fan-beam).
• The predictive value of HAL for hip fracture risk in European populations requires further investigation.