Summary
The incidence of vertebral fragility fractures has increased 2–4-fold during the past 30 years and the rate of increase is the same for both men and women. To arrest or reverse this increase, thorough understanding of normal, age-related changes in bone structure and strength is crucial. The human vertebral body is constructed to provide maximum strength with minimum bone mass. The strength is the sum of bone size, cortical thickness, trabecular architecture, and bone mass. With age, all these factors change due to the remodeling process, but the decline in bone strength is much more pronounced than the decline in mass. In individuals with very low bone mass, this discrepancy between mass and strength is even more marked. Structural studies have all shown a disruption of the trabecular network with age—mainly caused by perforation of horizontal supporting struts. These changes begin in the vertebral center. Later, a decline in cortical thickness is disclosed. The biomechanical consequence of this is a 4–6-fold decrease in vertebral strength during normal aging. As the structural changes cannot be reversed, it is difficult to increase bone strength by therapeutic regimens. Focus should therefore be placed on prevention. Three avenues are suggested: (1) to use the vast amount of existing biological data in a computer model to increase the understanding of the relationship among bone structure, mass, and strength, and to help identify the intervention regimens offering the best prospects of success; (2) to investigate characteristics of loadbearing trabecular bone that does not fracture; and (3) to focus more on life-style factors.
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References
Obrant K (1989) Editorial: Increasing age-adjusted risk of fragility fractures: a sign of increasing osteoporosis in successive generations? Calcif Tissue Int 44:157–167
Bengnér U, Johnell O, Redlund-Johnell I (1988) Changes in incidence and prevalence of vertebral fractures during 30 years. Calcif Tissue Int 42:293–296
Atkinson PJ (1967) Variation in trabecular structure of vertebrae with age. Calcif Tissue Res 1:24–32
Schmorl G, Junghanns H (1971) Development, growth, anatomy and function of the spine. Besemann EF (ed) The human spine in health and disease II. pp. 6–9. Grune & Stratton, New York, London
Gray H (1980) In: Williams PL, Warwich R (eds) Gray's anatomy, 36th ed. Churchill Livingstone, London, pp 756–757
Mosekilde Li, Mosekilde Le (1990) Sex differences in agerelated changes in vertebral size, density and biomechanical competence in normal individuals. Bone 11:67–73
Hansson T, Roos B (1981) The relation between bone mineral content, experimental compression fractures, and disc degeneration in lumbar vertebrae. Spine 6(2):147–153
Pesch HJ, Scharf HP, Lauer G, Seibold H (1980) Der Altersabhängige Verbundbau der Lendenwirbelkörper. Virchows Arch A Pathol Anat Histol 386:21–41
Vesterby A, Mosekilde Li, Gundersen JHG, Melsen F, Mosekilde Le, Holme K, Sørensen S (1991) Biologically meaningful determinants of the in vitro strength of lumbar vertebrae. Bone 12:219–224
Bell GH, Dunbar O, Beck JS, Gibb A (1967) Variations in strength of vertebrae with age and their relation to osteoporosis. Calcif Tissue Res 1:75–86
Weaver JK, Chalmers J (1966) Cancellous bone: its strength and changes with aging and an evaluation of some methods for measuring its mineral content. I. Age changes in cancellous bone. J. Bone Joint Surg 48-A(2):289–298
Mosekilde Li, Mosekilde Le, Danielsen CC (1987) Biomechanical competence of vertebral trabecular bone in relation to ash density and age in normal individuals. Bone 8:79–85
Davies KM, Recker RR, Heaney RP (1989) Normal vertebral dimensions and normal variation in serial measurements of vertebrae. J Bone Miner Res (4) 3:341–349
Kleerekoper M, Parfitt AM, Ellis BI (1984) Measurement of vertebral fracture rates in osteoporosis. In: Christiansen C, Osteoporosis I. Aalborg Stiftsbogtrykkeri, Denmark, pp 103–109
Melton LJ III, Kan SH, Frye MA, Wahner HW, O'Fallon M, Riggs BL (1989) Epidemiology of vertebral fractures in women. Am J Epidemiol 129(5):1000–1011
Hedlund LR, Gallagher JC (1988) Vertebral morphometry in diagnosis of spinal fractures. Bone Miner 5:59–67
Sauer P, Leidig G, Minne HW, Duckeck G, Schwartz W, Siromachkostov L, Ziegler R (1991) Spine Deformity Index (SDI) versus other objective procedures of vertebral fracture identification in patients with osteoporosis: a comparative study. J Bone Miner Res (6) 3:227–238
Kleerekoper M, Villaneuva AR, Stanciu J, Rao DS, Parfitt AM (1985) The role of three-dimensional trabecular microstructure in the pathogenesis of vertebral compression fractures. Calcif Tissue Int 37:594–597
Mosekilde Li, Mosekilde Le (1986) Normal vertebral body size and compressive strength: relations to age and to vertebral and iliac trabecular bone compressive: strength. Bone 7:207–212
Bergot C, Laval-Jeantet A-M, Pretêux F, Meunier A (1988) Measurement of anisotropic vertebral trabecular bone loss during aging by quantitative image analysis. Calcif Tissue Int 43: 143–149
Mosekilde Li (1988) Age-related changes in vertebral trabecular bone architecture-assessed by a new method. Bone 9:247–250
Mosekilde Li (1989) Sex differences in age-related loss of vertebral trabecular bone mass and structure-biomechanical consequences. Bone 10:425–432
Vesterby A, Gundersen JHG, Melsen F (1989) Star volume of marrow space and trabeculae of the first lumbar vertebra: sampling efficiency and biological variation. Bone 10:7–13
Whitehouse WJ, Dyson ED, Jackson CK (1971) The scanning electron microscope in studies of trabecular bone from a human vertebral body. J Anat (108) 3:481–496
Mosekilde Li (1990) Consequences of the remodelling process for vertebral trabecular bone structure: a scanning electron microscopy study (uncoupling of unloaded structures). Bone Miner 10:13–35
Parfitt AM (1984) Age-related structural changes in trabecular and cortical bone: cellular mechanisms and biomechanical consequences. Calcif Tissue Int 36:S123-S128
Feldkamp LE, Goldstein SA, Parfitt AM, Jesion G, Kleerekoper M (1989) The direct examination of three-dimensional bone architecture in vitro by computed tomography. J Bone Miner Res (4) 1:3–11
Rockoff SD, Sweet E, Bleustein J (1969) The relative contribution of trabecular and cortical bone to the strength of human lumbar vertebrae. Calcif Tissue Res 3:163–175
Hansson T, Roos B, Nachemson A (1980) The bone mineral content and ultimate compressive strength of lumbar vertebrae. Spine (5) 1:46–55
Keller TS, Hansson TH, Abram AC, Spengler DM, Panjabi MM (1989) Regional variations in the compressive properties of lumber vertebral trabeculae: effects of disc degeneration. Spine (14) 9:1012–1019
Galante J, Rostoker W, Ray RD (1970) Physical properties of trabecular bone. Calcif Tissue Res 5:236–246
Jensen KS, Mosekilde Li, Mosekilde Le (1990) A model of vertebral trabecular bone architecture and its mechanical properties. Bone 11:417–423
Kurowski P, Kubo A (1986) The relationship of degeneration of the invertebral disc to mechanical loading conditions on lumbar vertebrae. Spine (11) 7:726–732
Reeve J (1986) A stochastic analysis of iliac trabecular bone dynamics. Clin Orthop Rel Res 213:264–278
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Mosekilde, L. Vertebral structure and strengthIn vivo andIn vitro . Calcif Tissue Int 53 (Suppl 1), S121–S126 (1993). https://doi.org/10.1007/BF01673420
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DOI: https://doi.org/10.1007/BF01673420