European Spine Journal

, Volume 22, Issue 12, pp 2731–2739 | Cite as

Relation between radiological assessment and biomechanical stability of lumbar interbody fusion in a large animal model

  • R. J. KroezeEmail author
  • A. J. van der Veen
  • B. J. van Royen
  • R. A. Bank
  • M. N. Helder
  • T. H. Smit
Original Article



To relate the progress of vertebral segmental stability after interbody fusion surgery with radiological assessment of spinal fusion.


Twenty goats received double-level interbody fusion and were followed for a period of 3, 6 and 12 months. After killing, interbody fusion was assessed radiographically by two independent observers. Subsequently, the lumbar spines were subjected to four-point bending and rotational deformation, assessed with an optoelectronic 3D movement registration system. In addition, four caprine lumbar spines were analysed in both the native situation and after the insertion of a cage device, as to mimic the direct post-surgical situation. The range of motion (ROM) in flexion/extension, lateral bending and axial rotation was analysed ex vivo using a multi-segment testing system.


Significant reduction in ROM in the operated segments was already achieved with moderate bone ingrowth in flexion/extension (71 % reduction in ROM) and with only limited bone ingrowth in lateral bending (71 % reduction in ROM) compared to the post-surgical situation. The presence of a sentinel sign always resulted in a stable vertebral segment in both flexion/extension and lateral bending. For axial rotation, the ROM was already limited in both native and cage inserted situations, resulting in non-significant differences for all radiographic scores.


In vivo vertebral segment stability, defined as a significant reduction in ROM, is achieved in an early stage of spinal fusion, well before a radiological bony fusion between the vertebrae can be observed. Therefore, plain radiography underestimates vertebral segment stability.


Lumbar spinal fusion Animal model Motion-segment stability Mechanical testing Radiography 



This study was supported by the Dutch Program for Tissue Engineering (DPTE; #BGT 6734). The authors thank Klaas Walter Meijer, Paul Sinnige, Jerry Middelberg and Ger Vink from the animal facilities and Pieter Paul Vergroesen from the orthopaedic surgery department for their assistance during animal surgery and autopsy and Suzanne van Engelen from the Faculty of Human Movement Sciences for her assistance with mechanical testing of the spines.

Conflict of interest


Supplementary material

Supplementary material 1 (MPG 29936 kb)


  1. 1.
    Benzel EC (2009) Interbody device footprint and endplate engagement characteristics: biomechanical implications. Spine J 9:607–608PubMedCrossRefGoogle Scholar
  2. 2.
    Bozkus H, Chamberlain RH, Perez Garza LE, Crawford NR, Dickman CA (2004) Biomechanical comparison of anterolateral plate, lateral plate, and pedicle screws-rods for enhancing anterolateral lumbar interbody cage stabilization. Spine (Phila Pa 1976) 29:635–641Google Scholar
  3. 3.
    Busscher I, van Dieen JH, Kingma I et al (2009) Biomechanical characteristics of different regions of the human spine: an in vitro study on multilevel spinal segments. Spine (Phila Pa 1976) 34:2858–2864Google Scholar
  4. 4.
    Cunningham BW, Polly DW Jr (2002) The use of interbody cage devices for spinal deformity: a biomechanical perspective. Clin Orthop Relat Res 394:73–83PubMedCrossRefGoogle Scholar
  5. 5.
    Dawson-Saunders B, Trapp RG (1994) Basic and clinical biostatistics, 2nd edn. Prentice-Hall International Inc, Englewood CliffsGoogle Scholar
  6. 6.
    Erulkar JS, Grauer JN, Patel TC, Panjabi MM (2001) Flexibility analysis of posterolateral fusions in a New Zealand white rabbit model. Spine (Phila Pa 1976) 26:1125–1130Google Scholar
  7. 7.
    Goel VK, Panjabi MM, Patwardhan AG, Dooris AP, Serhan H (2006) Test protocols for evaluation of spinal implants. J Bone Jt Surg Am 88(Suppl 2):103–109CrossRefGoogle Scholar
  8. 8.
    Goel VK, Pope MH (1995) Biomechanics of fusion and stabilization. Spine (Phila Pa 1976) 20:85S–99SGoogle Scholar
  9. 9.
    Hoogendoorn RJ, Helder MN, Wuisman PI et al (2008) Adjacent segment degeneration: observations in a goat spinal fusion study. Spine (Phila Pa 1976) 33:1337–1343Google Scholar
  10. 10.
    Jurgens WJ, Van Dijk A, Zandieh-Doulabi B et al (2009) Freshly isolated stromal cells from the infrapatellar fat pad are suitable for a one-step surgical procedure to regenerate cartilage tissue. Cytotherapy 11:1–13CrossRefGoogle Scholar
  11. 11.
    Korinth MC, Moersch S, Ragoss C, Schopphoff E (2003) Biomechanicsl evaluation of a stand-alone interbody fusion cage based on porous TiO2/glass-ceramic on the human cervical spine. Biomed Tech (Berl) 48:349–355CrossRefGoogle Scholar
  12. 12.
    Krijnen MR, Mensch D, van Dieen JH, Wuisman PI, Smit TH (2006) Primary spinal segment stability with a stand-alone cage: in vitro evaluation of a successful goat model. Acta Orthop 77:454–461PubMedCrossRefGoogle Scholar
  13. 13.
    Krijnen MR, Mullender MG, Smit TH, Everts V, Wuisman PI (2006) Radiographic, histologic, and chemical evaluation of bioresorbable 70/30 poly-l-lactide-CO-D, l-lactide interbody fusion cages in a goat model. Spine 31:1559–1567PubMedCrossRefGoogle Scholar
  14. 14.
    Kroeze RJ, Helder MN, Roos WH et al (2010) The effect of ethylene oxide, glow discharge and electron beam on the surface characteristics of poly(l-lactide-co-caprolactone) and the corresponding cellular response of adipose stem cells. Acta Biomater 6:2060–2065PubMedCrossRefGoogle Scholar
  15. 15.
    Larsen JM, Rimoldi RL, Capen DA et al (1996) Assessment of pseudarthrosis in pedicle screw fusion: a prospective study comparing plain radiographs, flexion/extension radiographs, CT scanning, and bone scintigraphy with operative findings. J Spinal Disord 9:117–120PubMedCrossRefGoogle Scholar
  16. 16.
    Mcafee PC (1999) Interbody fusion cages in reconstructive operations on the spine. J Bone Jt Surg Am 81:859–880Google Scholar
  17. 17.
    Mcafee PC, Boden SD, Brantigan JW et al (2001) Symposium: a critical discrepancy—a criteria of successful arthrodesis following interbody spinal fusions. Spine (Phila Pa 1976) 26:320–334Google Scholar
  18. 18.
    Niemeyer TK, Koriller M, Claes L et al (2006) In vitro study of biomechanical behavior of anterior and transforaminal lumbar interbody instrumentation techniques. Neurosurgery 59:1271–1276PubMedCrossRefGoogle Scholar
  19. 19.
    Oxland TR, Lund T (2000) Biomechanics of stand-alone cages and cages in combination with posterior fixation: a literature review. Eur Spine J 9(Suppl 1):S95–S101PubMedCrossRefGoogle Scholar
  20. 20.
    Sengupta DK, Mehdian SM, Mulholland RC, Webb JK, Ohnmeiss DD (2002) Biomechanical evaluation of immediate stability with rectangular versus cylindrical interbody cages in stabilization of the lumbar spine. BMC Musculoskelet Disord 3:23PubMedCrossRefGoogle Scholar
  21. 21.
    Smit TH (2002) The use of a quadruped as an in vivo model for the study of the spine—biomechanical considerations. Eur Spine J 11:137–144PubMedCrossRefGoogle Scholar
  22. 22.
    Van Dijk M, Smit TH, Arnoe MF, Burger EH, Wuisman PI (2003) The use of poly-l-lactic acid in lumbar interbody cages: design and biomechanical evaluation in vitro. Eur Spine J 12:34–40PubMedGoogle Scholar
  23. 23.
    Van Dijk M, Smit TH, Burger EH, Wuisman PI (2002) Bioabsorbable poly-l-lactic acid cages for lumbar interbody fusion: three-year follow-up radiographic, histologic, and histomorphometric analysis in goats. Spine 27:2706–2714PubMedCrossRefGoogle Scholar
  24. 24.
    Van Dijk M, Smit TH, Sugihara S, Burger EH, Wuisman PI (2002) The effect of cage stiffness on the rate of lumbar interbody fusion: an in vivo model using poly(l-lactic acid) and titanium cages. Spine 27:682–688PubMedCrossRefGoogle Scholar
  25. 25.
    Vergroesen PP, Kroeze RJ, Helder MN, Smit TH (2011) The use of poly(l-lactide-co-caprolactone) as a scaffold for adipose stem cells in bone tissue engineering: application in a spinal fusion model. Macromol Biosci 11:722–730PubMedCrossRefGoogle Scholar
  26. 26.
    Wang ST, Goel VK, Kubo S et al (2003) Comparison of stabilities between obliquely and conventionally inserted Bagby and Kuslich cages as posterior lumbar interbody fusion in a cadaver model. J Chin Med Assoc 66:676–681PubMedGoogle Scholar
  27. 27.
    Zdeblick TA, Phillips FM (2003) Interbody cage devices. Spine (Phila Pa 1976) 28:S2–S7Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • R. J. Kroeze
    • 1
    • 2
    • 5
    Email author
  • A. J. van der Veen
    • 3
    • 5
  • B. J. van Royen
    • 1
    • 5
  • R. A. Bank
    • 4
    • 5
  • M. N. Helder
    • 1
    • 5
  • T. H. Smit
    • 1
    • 5
  1. 1.Department of Orthopaedic SurgeryVU University Medical CenterAmsterdamThe Netherlands
  2. 2.Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA)Universiteit van Amsterdam and Vrije UniversiteitAmsterdamThe Netherlands
  3. 3.Department of Physics and Medical TechnologyVU University Medical CenterAmsterdamThe Netherlands
  4. 4.Department of Medical BiologyUniversity Medical Center GroningenGroningenThe Netherlands
  5. 5.MOVE/Skeletal Tissue Engineering Group Amsterdam (STEGA)AmsterdamThe Netherlands

Personalised recommendations