Journal of Failure Analysis and Prevention

, Volume 13, Issue 6, pp 678–683 | Cite as

Cervical Stent Failure Analysis

Case History---Peer-Reviewed
  • 183 Downloads

Abstract

Harrington rods failed after a short period in service. Metallurgical analysis showed (1) notches were present on the rods, (2) small cracks present in the bent regions of the rod, and (3) the fractures occurred at clamped locations. All of these conditions can shorten the fatigue life by eliminating the crack initiation stage of fatigue and allowing corrosion fatigue to occur.

Keywords

Annealing Biomaterials Failure analysis Titanium 

References

  1. 1.
  2. 2.
    L.A. Shepard et al., Characterization of a failed spinal implant (Harrington rod), in ASM Conference Proceedings, Metals Park (1988), pp. 411–418Google Scholar
  3. 3.
    ASTM F136-02a, Standard specification for wrought titanium–6 aluminum–4 vanadium ELI (extra low interstitial) alloy for surgical implant applications (UNS R56401), 2002Google Scholar
  4. 4.
    R. Boyer, E.W. Collings, G. Welsch (eds.), Materials Properties Handbook: Titanium Alloys (ASM International, Materials Park, 1994), pp. 483–636Google Scholar
  5. 5.
    H.J. Snyder et al., Fatigue fracture of 316L SS screws employed for surgical implanting, in Handbook of Case Histories in Failure Analysis, vol. 1, ed. by K.A. Esakul (ASM International, Materials Park, 1992)Google Scholar
  6. 6.
    M. Prikryl et al., Role of corrosion in Harrington and Luque rods failure. Biomaterials 10, 109–117 (1989)CrossRefGoogle Scholar
  7. 7.
    M. Hahn et al., The influence of material and design features on the mechanical properties of transpedicular spinal fixation implants. J. Biomed. Mater. Res. 63, 354–362 (2002)CrossRefGoogle Scholar
  8. 8.
    H. Stürz et al., Damage analysis of the Harrington Rod fracture after scoliosis operation. Arch. Orthop. Trauma Surg. 95, 113–122 (1979)CrossRefGoogle Scholar
  9. 9.
    J.S. Kirkpatrick et al., Corrosion on spinal implants. J. Spinal Disord. Tech. 18, 247–251 (2005)Google Scholar
  10. 10.
    A.C. Fraker, Forms of corrosion in implant materials, in Metals Handbook, vol 13, 9th edn. (ASM International, Materials Park, 1987), pp. 1324–1335Google Scholar
  11. 11.
    L. Aulisa et al., Corrosion of the Harrington’s instrumentation and biological behavior of the rod–human spine system. Biomaterials 3, 246–249 (1982)CrossRefGoogle Scholar
  12. 12.
    J.B. Brunski et al., Stresses in a Harrington distraction rod: their origin and relationship to fatigue fractures in vivo. J. Biomech. Eng. 105, 101–107 (1983)CrossRefGoogle Scholar
  13. 13.
    C. Sittig et al., Surface characterization of implant materials c.p. Ti, Ti–6Al–4V and Ti–6Al–4V with different pretreatments. J. Mater. Sci. Mater. Med. 10(1), 35–46 (1999)CrossRefGoogle Scholar
  14. 14.
    S. Hur, The 360° cold bending of Ti–6Al–4V large diameter seamless tube. JOM 51(6), 28–30 (1999)CrossRefGoogle Scholar
  15. 15.
    R.W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials (Wiley, New York, 1976)Google Scholar

Copyright information

© ASM International 2013

Authors and Affiliations

  1. 1.Talbott Associates, Inc.PortlandUSA

Personalised recommendations