Biomechanics of the aging spine

  • Stephen J. Ferguson
  • Thomas Steffen
Conference paper


The human spine is composed of highly specific tissues and structures, which together provide the extensive range of motion and considerable load carrying capacity required for the physical activities of daily life. Alterations to the form and composition of the individual structures of the spine with increasing age can increase the risk of injury and can have a profound influence on the quality of life. Cancellous bone forms the structural framework of the vertebral body. Individual trabeculae are oriented along the paths of principal forces and play a crucial role in the transfer of the predominantly compressive forces along the spine. Age-related changes to the cancellous core of the vertebra includes a loss of bone mineral density, as well as morphological changes including trabecular thinning, increased intratrabecular spacing, and loss of connectivity between trabeculae. Material and morphological changes may lead to an increased risk of vertebral fracture. The vertebral endplate serves the dual role of containing the adjacent disc and evenly distributing applied loads to the underlying cancellous bone and the cortex of the vertebra. With aging, thinning of the endplate, and loss of bone mineral density increases the risk of endplate fracture. Ossification of the endplate may have consequences for the nutritional supply and hydration of the intervertebral disc. The healthy intervertebral disc provides mobility to the spine and transfers load via hydrostatic pressurization of the hydrated nucleus pulposus. Changes to the tissue properties of the disc, including dehydration and reorganization of the nucleus and stiffening of the annulus fibrosus, markedly alter the mechanics of load transfer in the spine. There is no direct correlation between degenerative changes to the disc and to the adjacent vertebral bodies. Furthermore, advancing age is not the sole factor in the degeneration of the spine. Further study is crucial for understanding the unique biomechanical function of the aging spine.


Aging spine Biomechanics Osteoporosis Vertebral endplate Disc degeneration 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Acaroglu ER, Iatridis JC, Setton LA, Foster RJ, Mow VC, Weidenbaum M (1995) Degeneration and aging affect the tensile behavior of human lumbar anulus fibrosus. Spine 20:2690–2701PubMedGoogle Scholar
  2. 2.
    Adams MA, McNally DS, Dolan P (1996) ‘stress’ distributions inside intervertebral discs. The effects of age and degeneration. J Bone Joint Surg Br 78:965–972CrossRefPubMedGoogle Scholar
  3. 3.
    Ayotte DC, Ito K, Perren SM, Tepic S (2000) Direction-dependent constriction flow in a poroelastic solid: the intervertebral disc valve. J Biomech Eng 122:587–593CrossRefPubMedGoogle Scholar
  4. 4.
    Brinckmann P, Biggemann M, Hilweg D (1989) Prediction of the compressive strength of human lumbar vertebrae. Spine 14:606–610PubMedGoogle Scholar
  5. 5.
    Cummings SR, Black D (1995) Bone mass measurements and risk of fracture in Caucasian women: a review of findings from prospective studies. Am J Med 98:24S–28SCrossRefPubMedGoogle Scholar
  6. 6.
    Dai L (1998) The relationship between vertebral body deformity and disc degeneration in lumbar spine of the senile. Eur Spine J 7:40–44CrossRefPubMedGoogle Scholar
  7. 7.
    Ebara S, Iatridis JC, Setton LA, Foster RJ, Mow VC, Weidenbaum M (1996) Tensile properties of nondegenerate human lumbar anulus fibrosus. Spine 21:452–461CrossRefPubMedGoogle Scholar
  8. 8.
    Ferguson SJ, Ito K, Nolte LP (2003) Fluid flow and convective transport of solutes within the intervertebral disc. J Biomech (in press)Google Scholar
  9. 9.
    Grant JP, Oxland TR, Dvorak MF (2001) Mapping the structural properties of the lumbosacral vertebral endplates. Spine 26:889–896CrossRefPubMedGoogle Scholar
  10. 10.
    Grant JP, Oxland TR, Dvorak MF, Fisher CG (2002) The effects of bone density and disc degeneration on the structural property distributions in the lower lumbar vertebral endplates. J Orthop Res 20:1115–1120CrossRefPubMedGoogle Scholar
  11. 11.
    Hansson TH, Keller TS, Spengler DM (1987) Mechanical behavior of the human lumbar spine. II. Fatigue strength during dynamic compressive loading. J Orthop Res 5:479–487CrossRefPubMedGoogle Scholar
  12. 12.
    Hansson T, Keller T, Jonson R (1988) Fatigue fracture morphology in human lumbar motion segments. J Spinal Disord 1:33–38PubMedGoogle Scholar
  13. 13.
    Harada A, Okuizumi H, Miyagi N, Genda E (1998) Correlation between bone mineral density and intervertebral disc degeneration. Spine 23:857–861CrossRefPubMedGoogle Scholar
  14. 14.
    Iatridis JC, Setton LA, Weidenbaum M Mow VC (1997) Alterations in the mechanical behavior of the human lumbar nucleus pulposus with degeneration and aging. J Orthop Res 15:318–322CrossRefPubMedGoogle Scholar
  15. 15.
    Iatridis JC, Setton LA, Foster RJ, Rawlins BA, Weidenbaum M, Mow VC (1998) Degeneration affects the anisotropic and nonlinear behaviors of human anulus fibrosus in compression. J Biomech 31:535–544CrossRefPubMedGoogle Scholar
  16. 16.
    Jensen ME, Evans AJ, Mathis JM, Kallmes DF, Cloft HJ, Dion JE (1997) Percutaneous polymethylmethacrylate vertebroplasty in the treatment of osteoporotic vertebral body compression fractures: technical aspects. AJNR Am J Neuroradiol 18:1897–1904PubMedGoogle Scholar
  17. 17.
    Keller TS (1994) Predicting the compressive mechanical behavior of bone. J Biomech 27:1159–1168CrossRefPubMedGoogle Scholar
  18. 18.
    Keller TS, Hansson TH, Abram AC, Spengler DM, Panjabi MM (1989) Regional variations in the compressive properties of lumbar vertebral trabeculae. Effects of disc degeneration. Spine 14:1012–1019PubMedGoogle Scholar
  19. 19.
    Keller TS, Moeljanto E, Main JA, Spengler DM (1992) Distribution and orientation of bone in the human lumbar vertebral centrum. J Spinal Disord 5:60–74PubMedGoogle Scholar
  20. 20.
    Keller TS, Ziv I, Moeljanto E, Spengler DM (1993) Interdependence of lumbar disc and subdiscal bone properties: a report of the normal and degenerated spine. J Spinal Disord 6:106–113PubMedGoogle Scholar
  21. 21.
    Leidig-Bruckner G, Limberg B, Felsenberg D, Bruckner T, Holder S, Kather A, Miksch J, Wuster C, Ziegler R, Scheidt-Nave C (2000) Sex difference in the validity of vertebral deformities as an index of prevalent vertebral osteoporotic fractures: a population survey of older men and women. Osteoporos Int 11:102–119PubMedGoogle Scholar
  22. 22.
    Mazess RB (1982) On aging bone loss. Clin Orthop 239–252Google Scholar
  23. 23.
    McBroom RJ, Hayes WC, Edwards WT, Goldberg RP, White AA III (1985) Prediction of vertebral body compressive fracture using quantitative computed tomography. J Bone Joint Surg Am 67:1206–1214PubMedGoogle Scholar
  24. 24.
    National Institutes of Health (2003) Osteoporosis prevention, diagnosis and therapy. NIH consensus statement 17:1–36Google Scholar
  25. 25.
    Neumann P, Ekstrom LA, Keller TS, Perry L, Hansson TH (1994) Aging, vertebral density, and disc degeneration alter the tensile stress-strain characteristics of the human anterior longitudinal ligament. J Orthop Res 12:103–112CrossRefPubMedGoogle Scholar
  26. 26.
    Oner FC, van der Rijt RR, Ramos LM, Dhert WJ, Verbout AJ (1998) Changes in the disc space after fractures of the thoracolumbar spine. J Bone Joint Surg Br 80:833–839CrossRefPubMedGoogle Scholar
  27. 27.
    Oxland TR, Grant JP, Dvorak MF, Fisher CG (2003) Effects of endplate removal on the structural properties of the lower lumbar vertebral bodies. Spine 28:771–777CrossRefPubMedGoogle Scholar
  28. 28.
    Polikeit A (2002) Finite element analyses of the lumbar spine: clinical applications. Ph. D. Thesis, University of BerneGoogle Scholar
  29. 29.
    Recke P von der, Hansen MA, Overgaard K, Christiansen C (1996) The impact of degenerative conditions in the spine on bone mineral density and fracture risk prediction. Osteoporos Int 6:43–49CrossRefPubMedGoogle Scholar
  30. 30.
    Resch A, Schneider B, Bernecker P, Battmann A, Wergedal J, Willvonseder R, Resch H (1995) Risk of vertebral fractures in men: relationship to mineral density of the vertebral body. AJR Am J Roentgenol 164:1447–1450PubMedGoogle Scholar
  31. 31.
    Roberts S, Urban JP, Evans H, Eisenstein SM (1996) Transport properties of the human cartilage endplate in relation to its composition and calcification. Spine 21:415–420CrossRefPubMedGoogle Scholar
  32. 32.
    Roberts S, McCall IW, Menage J, Haddaway MJ, Eisenstein SM (1997) Does the thickness of the vertebral subchondral bone reflect the composition of the intervertebral disc? Eur Spine J 6:385–389CrossRefPubMedGoogle Scholar
  33. 33.
    Shirado O, Kaneda K, Tadano S, Ishikawa H, McAfee PC, Warden KE (1992) Influence of disc degeneration on mechanism of thoracolumbar burst fractures. Spine 17:286–292PubMedGoogle Scholar
  34. 34.
    Silva MJ, Wang C, Keaveny TM, Hayes WC (1994) Direct and computed tomography thickness measurements of the human, lumbar vertebral shell and endplate. Bone 15:409–414CrossRefPubMedGoogle Scholar
  35. 35.
    Silva MJ, Keaveny TM, Hayes WC (1997) Load sharing between the shell and centrum in the lumbar vertebral body. Spine 22:140–150CrossRefPubMedGoogle Scholar
  36. 36.
    Twomey LT, Taylor JR (1987) Age changes in lumbar vertebrae and intervertebral discs. Clin Orthop 97–104Google Scholar
  37. 37.
    Urban JP, McMullin JF (1988) Swelling pressure of the lumbar intervertebral discs: influence of age, spinal level, composition, and degeneration. Spine 13:179–187PubMedGoogle Scholar
  38. 38.
    Vernon-Roberts B (1988) Disc pathology and disease states. In: Ghosh P (ed) The biology of the intervertebral disc. CRC, Boca Raton, pp 73–120Google Scholar
  39. 39.
    Wagner AL, Murtagh FR, Arrington JA, Stallworth D (2000) Relationship of Schmorl’s nodes to vertebral body endplate fractures and acute endplate disk extrusions. AJNR Am J Neuroradiol 21:276–281Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Stephen J. Ferguson
    • 1
  • Thomas Steffen
    • 2
  1. 1.M.E. Müller Research Center for Orthopaedic Surgery, Institute for Surgical Technology and BiomechanicsUniversity of BerneBerneSwitzerland
  2. 2.Orthopaedic Research LaboratoryMcGill UniversityMontrealCanada

Personalised recommendations