Age-related changes in bone mineral density of the scaphoid and distal radius: A quantitative computed tomography study.

Background: Scaphoid fractures predominantly occur in young males, while distal radius fractures occur in elderly females, despite similar injury mechanisms. We hypothesized that age-related bone mineral density (BMD) changes differ between these bones, explaining their distinct fracture patterns. This study compared age-related BMD changes between the scaphoid and distal radius using quantitative computed tomography (qCT).

Methods: We analyzed 167 cases (110 males, 57 females; mean age 45.2 ± 18.1 years) who underwent qCT including forearm and carpal bones. Exclusion criteria included fractures, arthritis, and implants. BMD was measured separately for cortical and cancellous bone in both the scaphoid and distal radius using phantom-corrected Hounsfield values. Correlations between age and BMD were evaluated using Pearson correlation coefficients.

Results: The distal radius showed significant negative correlation with age in overall BMD (r = -0.44) and cancellous BMD (r = -0.40), while the scaphoid showed no significant correlation. Females demonstrated significantly stronger negative correlations than males in both bones. Age-related BMD decline occurred predominantly in cancellous bone. The radius/scaphoid BMD ratio decreased with age (r = -0.51), indicating relatively greater BMD decline in the radius.

Conclusion: The distal radius exhibits stronger age-related BMD decline than the scaphoid, particularly in cancellous bone. This differential aging pattern may explain why scaphoid fractures predominate in young individuals while distal radius fractures are more common in the elderly.