Chapter 45 Osteoporosis in AdultsPhoto Album

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.1: (A) Normal trabecular bone. Note the highly interconnected vertical and horizontal bars, fairly homogeneous size and shape of holes, and platelike appearance of many of the trabecular units. (B) Osteoporotic bone. Note substantial reduction in the amount of bone substance per unit volume compared to normal bone (A). Note the narrow rodlike appearance of vertical trabeculae compared to the normal platelike structures. Note the wide variation in the size of holes throughout the trabecular structure. In many regions, trabecular struts are hanging in space without connection to neighboring structures. Courtesy Dr. David Dempster. Copyright David Dempster. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.2: Age-specific incidence rates for hip, vertebral, and distal forearm fractures in men and women. Data derived from the population of Rochester, Minnesota. From C. Cooper, L.J. Melton, III, Epidemiology of osteoporosis, Trends Endocrinol. Metab. 3 (1992) 224229. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.3: Low-power view of osteoblasts lining the bone surface. From C.A. Lee, T.A. Einhorn, The bone organ system, form and function, in: R. Marcus, D. Feldman, J. Kelsey, Osteoporosis, Academic Press, San Diego, CA, 2001, 320 [7], with permission. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.4: Osteocytes occupying individual lacunae with extensive canalicular interconnections. From C.A. Lee, T.A. Einhorn, The bone organ system, form and function, in: R. Marcus, D. Feldman, J. Kelsey, Osteoporosis, Academic Press, San Diego, CA, 2001, 320 [7], with permission. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.5: Low-power view of osteoclasts occupying resorption lacunae. From C.A. Lee, T.A. Einhorn, The bone organ system, form and function, in: R. Marcus, D. Feldman, J. Kelsey, Osteoporosis, Academic Press, San Diego, CA, 2001, 320 [7], with permission. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.6: The bone remodelling cycle. This drawing represents a region of trabecular bone. All remodelling events occur on the bone surface. (a) 90% of bone surface is generally covered by thin layer of dormant lining cells. (b) Coalescence of osteoclast precursors at a site on the bone surface with creation of multinucleated osteoclasts. (c) Osteoclasts remove a divot of bone, reaching 60 μm in depth by 68 weeks. (d) Soluble factors released by osteoclastic resorption recruit a new wave of cell proliferation (Preosteoblasts) into the base of the resorption cavity. (e) Preosteoblasts acquire the osteoblast phenotype. (f) Osteoblasts secrete new bone matrix, which begins to acquire mineral after a thickness of approximately 20 μm is achieved. (g) New mineralized bone almost fully replaces resorbed bone by approximately 6 months. Small deficits are left, reflecting remodelling inefficiency and accounting for the process of age-related bone loss. Copyright Robert Marcus. Copyright © 2016 Elsevier Inc. All rights reserved.

Copyright © 2016 Elsevier Inc. All rights reserved. FIGURE 45.7: The curvilinear nature of skeletal response to mechanical loading. Copyright Robert Marcus. Copyright © 2016 Elsevier Inc. All rights reserved.