Osteoporosis and Bone Health


Fourth Edition advance copy

Disclaimer: This chapter will be included in the forthcoming The Burden of Musculoskeletal Diseases in the United States, Fourth Edition. The United States Bone and Joint Initiative is making it available here prior to its final print publication. This chapter has not been finalized for publication; therefore, it may contain errors of fact, interpretation, or information. The United States Bone and Joint Initiative editors and staff are not responsible for the use of any potentially misleading or inaccurate information or data. Click here for the suggested citation.


Lead Author(s): 

Nicole C. Wright, PhD, MPH
Marc C. Hochberg, MD, MPH, MACP, MACR

Supporting Author(s): 

Sylvia I. Watkins-Castillo, PhD

Osteoporosis is a chronic musculoskeletal condition characterized by reductions in bone mass and quality accompanied by microarchitectural changes that lead to reduced bone strength. Reductions in bone mass, quality and strength increase the risk for fragility fractures. The primary diagnostic test for osteoporosis is measurement of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA). DXA testing provides an estimate of areal BMD in g/cm2,1 and the estimate is converted into a T-score by comparing it to the distribution of BMD levels of young adults. Using thresholds developed by the World Health Organization, osteoporosis is defined as a T-score ≤ -2.5. T-scores between -2.5 and -1.0 identify individuals with low bone mass (osteopenia) and T-scores ≥ -1.0 represent normal bone mass.2 It should be noted that older persons who sustain a hip fracture and/or a vertebral (spine) fracture are considered to have osteoporosis even in the absence of undergoing BMD measurement.

  • 1. Bone mineral content, measured by dual-energy x-ray absorptiometry (DEXA), divided by the bone area in square centimeters.
  • 2. World Health Organization: WHO Scientific Group on the assessment of osteoporosis at primary healthcare level. Summary Meeting Report, Brussels, Belgium, 5-7 May 2004: page 12. http://www.who.int/chp/topics/Osteoporosis.pdf   Accessed July 2, 2018.


  • Fourth Edition

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