Gender differences in vertebral sizes in adults: biomechanical implications

Radiology. 1994 Mar;190(3):678-82. doi: 10.1148/radiology.190.3.8115610.


Purpose: To determine if vertebral bone densities or vertebral body sizes contribute to gender differences in vertebral bone mass in adults.

Materials and methods: Cancellous and cortical bone densities and dimensions of three lumbar vertebrae in 25 women and 18 men were measured with quantitative computed tomography (CT) and statistically analyzed.

Results: Neither cancellous nor cortical vertebral bone densities differed in healthy adults. Vertebral bodies in women had lower cross-sectional areas (8.22 cm2 +/- 1.09 [standard deviation] versus 10.98 cm2 +/- 1.25, P < .001) and volumes (22.42 cm3 +/- 2.40 versus 30.86 cm3 +/- 2.6, P < .001). These differences also were evident in men and women matched for age, weight, vertebral bone density, and vertebral body height. Overall cross-sectional areas of vertebral bodies are 25% smaller in women than men. Vertebral bone densities do not differ between sexes. Estimates of mechanical stress within vertebral bodies are 30%-40% higher in women than men for equivalent applied loads.

Conclusion: Smaller vertebral bodies in women confer biomechanical disadvantages that may contribute to more vertebral fractures in elderly women.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Body Constitution
  • Bone Density / physiology*
  • Female
  • Humans
  • Lumbar Vertebrae / anatomy & histology*
  • Lumbar Vertebrae / diagnostic imaging
  • Male
  • Osteoporosis / epidemiology
  • Osteoporosis, Postmenopausal / epidemiology
  • Risk Factors
  • Sex Characteristics*
  • Spinal Fractures / epidemiology
  • Stress, Mechanical
  • Tomography, X-Ray Computed / methods