Replacing the nucleus pulposus of the intervertebral disk: prediction of suitable properties of a replacement material using finite element analysis

  • J. R. Meakin


An axisymmetric finite element model of a human lumbar disk was developed to investigate the properties required of an implant to replace the nucleus pulposus. In the intact disk, the nucleus was modeled as a fluid, and the annulus as an elastic solid. The Young's modulus of the annulus was determined empirically by matching model predictions to experimental results. The model was checked for sensitivity to the input parameter values and found to give reasonable behavior. The model predicted that removal of the nucleus would change the response of the annulus to compression. This prediction was consistent with experimental results, thus validating the model. Implants to fill the cavity produced by nucleus removal were modeled as elastic solids. The Poisson's ratio was fixed at 0.49, and the Young's modulus was varied from 0.5 to 100 MPa. Two sizes of implant were considered: full size (filling the cavity) and small size (smaller than the cavity). The model predicted that a full size implant would reverse the changes to annulus behavior, but a smaller implant would not. By comparing the stress distribution in the annulus, the ideal Young's modulus was predicted to be approximately 3 MPa. These predictions have implications for current nucleus implant designs. © 2001 Kluwer Academic Publishers


Finite Element Analysis Finite Element Model Stress Distribution Intervertebral Disk Nucleus Pulposus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    D. W. L. HUKINS, in “The Biology of the Intervertebral Disc”, volume 1, edited by P. Ghosh (CRC Press, Boca Raton, 1988) p. 1.Google Scholar
  2. 2.
    N. BOGDUK, in “Clinical Anatomy of the Lumbar Spine”, 3rd edition (Churchill Livingstone, Melbourne, 1997) p. 13.Google Scholar
  3. 3.
    R. W. PORTER, in “Management of Back Pain”, 2nd edition (Churchill Livingstone, Edinburgh, 1993) p. 180.Google Scholar
  4. 4.
    P. KAMBIN and H. GELLMAN, Clin. Orthop. 174 (1983) 127.Google Scholar
  5. 5.
    P. KAMBIN and L. ZHOU, Clin. Orthop. 337 (1997) 49.Google Scholar
  6. 6.
    D. S. J. CHOY, P. W. ASCHER, H. S. RANU, S. SADDEKNI, D. ALKAITIS, W. LIEBER, J. HUGHES, S. DIWAN and P. ALTMAN, Spine 17 (1992) 949.Google Scholar
  7. 7.
    D. WARDLAW, in “Lumbar Spine Disorders: Current Concepts”, edited by R. M. Aspden and R. W. Porter (World Scientific, Singapore, 1995) p. 167.Google Scholar
  8. 8.
    E. SEROUSSI, M. H. KRAG, D. L. MULLER and M. H. POPE, J. Orthop. Res. 7 (1989) 122.Google Scholar
  9. 9.
    J. R. MEAKIN, Ph.D. thesis (University of Aberdeen, UK, 1999).Google Scholar
  10. 10.
    J. R. MEAKIN and D. W. L. HUKINS, J. Bone Joint Surg. 826 Suppl I (2000) 38.Google Scholar
  11. 11.
    V. K. GOEL, B.T. MONROE, L. G. GILBERTSON and P. BRINCKMANN, Spine 20 (1995) 689.Google Scholar
  12. 12.
    M. B. COVENTRY, R. K. GHORMLEY and J. W. KERNOHAN, J. Bone Joint Surg. 27 (1945) 233.Google Scholar
  13. 13.
    Idem., ibid. 27 (1945) 460.Google Scholar
  14. 14.
    C. D. RAY, in “Clinical EfÆcacy and Outcome in the Diagnosis and Treatment of Low Back Pain”, edited by J. W. Weinstein (Raven Press, New York, 1992) p. 205.Google Scholar
  15. 15.
    T. BELYTSCHKO, R. F. KULAK and A. B. SCHULTZ, J. Biomech. 7 (1974) 277.Google Scholar
  16. 16.
    J. R. MEAKIN, R. M. ASPDEN and D. W. L. HUKINS, Comments Theor. Biol. 5 (1998) 49.Google Scholar
  17. 17.
    B. M. NIGG, in “Biomechanics of the Musculo-skeletal System”, edited by B. M. Nigg and W. Herzog (John Wiley and Sons, Chichester, 1994) p. 367.Google Scholar
  18. 18.
    D. W. L. HUKINS. Proc. R. Soc. Lond. B 249 (1992) 281.Google Scholar
  19. 19.
    ANSYS “Modelling and Meshing Guide”, 2nd edition (ANSYS Inc., Houston, PA, USA, 1997) p. 2.11.Google Scholar
  20. 20.
    ANSYS “Elements Reference” 9th edition, (ANSYS Inc., Houston, PA, USA, 1997).Google Scholar
  21. 21.
    J. S. POONI, BSc Thesis (University of Manchester, UK, 1983).Google Scholar
  22. 22.
    P. BRINCKMANN and H. GROOTENBOER, Spine 16 (1991) 641.Google Scholar
  23. 23.
    M. SHEA, T. Y. TAKEUCHI, R. H. WITTENBERG, A. A. WHITE I I I and W. C. HAYES, J. Spinal Disord. 7 (1994) 317.Google Scholar
  24. 24.
    H. YANG and V. L. KI SH, J. Biomech. 21 (1988) 865.Google Scholar
  25. 25.
    J. M. GERE and S. P. TIMOSHENKO, “Mechanics of Materials”, 2nd SI edition (Wadsworth International, Sydney, 1985) p. 21.Google Scholar
  26. 26.
    E. GOWER and V. PEDRINI, J. Bone Joint Surg. 51A (1969) 1154.Google Scholar
  27. 27.
    G. LYONS, S. M. EISENSTEIN and M. B. E. SWEET, Biochim. Biophys. Acta 673 (1981) 443.Google Scholar
  28. 28.
    E. R. ACAROGLU, J. C. IATRIDIS, L. A. SETTON, R. J. FOSTER, V. C. MOW and M. WEIDENBAUM, Spine 20 (1995) 2690.Google Scholar
  29. 29.
    C. WU and R. F. YAO, J. Biomech. 9 (1976) 1.Google Scholar
  30. 30.
    F. MARCHAND and A. M. AHMED, Trans. Orthop. Res. Soc. 14 (1989) 355.Google Scholar
  31. 31.
    B. A. BEST, F. GUILAK, L. A. SETTON, W. ZHU, F. SAEDNEJAD, A. RATCLIFFE, M. WEIDENBAUM and V. C. MOW, Spine 19 (1994) 212.Google Scholar
  32. 32.
    L. SKAGGS, M. WEIDENBAUM, J. C. IATRIDI S, A. RATCLIFFE and V. C. MOW, bid. 19 (1994) 1310.Google Scholar
  33. 33.
    S. EBARA, J. C. IATRIDIS, L. A. SETTON, R. J. FOSTER, V. C. MOW and M. WEIDENBAUM, ibid. 21 (1996) 452.Google Scholar
  34. 34.
    S. UMEHARA, S. TADANO, K. ABUMI, K. KATAGIRI, K. KANEDA and T. UKAI, ibid. 21 (1996) 811.Google Scholar
  35. 35.
    M. A. ADAMS and T. P. GREEN, Eur. Spine J. 2 (1993) 203.Google Scholar
  36. 36.
    A. D. HOLMES, D. W. L. HUKINS and A. J. FREEMONT, Spine 18 (1993) 128.Google Scholar
  37. 37.
    W. J. VIRGIN, J. Bone Joint Surg. 33B (1951) 607.Google Scholar
  38. 38.
    T. BROWN, R. J. HANSEN and A. J. YORRA, ibid. 39A (1957)1135.Google Scholar
  39. 39.
    K. L. MARKOLF, J. Bone Joint Surg. 54A (1972) 511.Google Scholar
  40. 40.
    K. H. WENGER and J. D. SCHLEGEL, Clin. Biomech. 12 (1997) 438.Google Scholar
  41. 41.
    K. L. MARKOLF and J. M. MORRIS, J. Bone Joint Surg. 54A (1974) 511.Google Scholar
  42. 42.
    J. VINCENT “Structural Biomaterials”, revised edition (Princeton University Press, Princeton, 1990) p. 101.Google Scholar
  43. 43.
    J. B. PARK and R. S. LAKES “Biomaterials: An Introduction”, 2nd edition (Plenum Press, New York, 1992) p. 221.Google Scholar
  44. 44.
    D. BRICKLEY-PARSONS and M. J. GLIMCHER, Spine 9 (1984) 148.Google Scholar
  45. 45.
    J. D. KUNTZ, “Intervertebral Disc Prosthesis” (US patent number 434 9922, 1982).Google Scholar
  46. 46.
    C. D. RAY, E. A. DICKHUDT, P. J. LEDOUX and B. A. FRUTIGER, “Prosthetic Spinal Disc Nucleus” (US patent number 567 4295, 1997).Google Scholar
  47. 47.
    Q.-B. BAO and P. A. HIGHAM, “Hydrogel Intervertebral Disc Nucleus with Diminished Lateral Bulging” (US patent number 553 4028, 1996).Google Scholar
  48. 48.
    Q.-B. BAO, P. A. HIGHAM, C. S. BAGGA and H. A. YUAN, “Method and apparatus for injecting an elastic spinal implant” (US patent number 580 0549, 1998).Google Scholar

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • J. R. Meakin
    • 1
  1. 1.Department of Biomedical Physics and BioengineeringUniversity of AberdeenAberdeenUK

Personalised recommendations