RT Book, Section A1 Jameson, J. Larry A1 Fauci, Anthony S. A1 Kasper, Dennis L. A1 Hauser, Stephen L. A1 Longo, Dan L. A1 Loscalzo, Joseph SR Print(0) ID 1167068822 T1 Osteoporosis and Osteomalacia T2 Harrison's Manual of Medicine, 20e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781260455342 LK accessmedicine.mhmedical.com/content.aspx?aid=1167068822 RD 2024/03/29 AB Osteoporosis is defined as a reduction in the strength of bone that leads to increased risk of fractures. It is defined operationally as a bone density that falls 2.5 SD below the mean for a young normal individual (a T-score of <–2.5). Those with a T-score of <1.0 (osteopenia) have low bone density and are at increased risk for osteoporosis. The most common sites for osteoporosis-related fractures are the vertebrae, hip, and distal radius.