Distinct Cortical Microstructure in Postmenopausal Women with Distal Radius and Proximal Humerus Fractures

Area of Science:

• Orthopedics and Bone Health
• Osteoporosis Research
• Skeletal Microstructure Analysis

Background:

• Distal radius fractures (DRF) and proximal humerus fractures (PHF) are prevalent in postmenopausal women with osteoporosis.
• The relationship between bone microstructural deficits and fracture type at peripheral sites remains under-investigated.

Purpose of the Study:

• To investigate whether bone microstructural deficits differ between postmenopausal women with DRF and PHF.
• To compare bone geometry and microarchitecture at peripheral skeletal sites between these fracture groups.

Main Methods:

• Retrospective study including treatment-naïve postmenopausal women with DRF or PHF.
• Propensity score matching used to create comparable groups (n=30 per group).
• Assessment included biochemical testing, DXA, and high-resolution peripheral quantitative CT (HR-pQCT) for bone microstructural evaluation.

Main Results:

• Both groups exhibited reduced bone mineral density (BMD) and microarchitectural parameters compared to reference values.
• The PHF group showed significantly reduced bone geometry at the distal radius (total, trabecular, cortical area) compared to the DRF group.
• Reduced cortical thickness was observed in the PHF group at both the distal radius and tibia, independent of areal BMD.

Conclusions:

• Proximal humerus fractures are associated with distinct bone microstructural deficits, specifically reduced cortical thickness and unfavorable bone geometry.
• These findings suggest that bone quality, beyond areal BMD, plays a crucial role in fracture risk stratification in postmenopausal women.