Skip to main content

Advertisement

SpringerLink
Log in

Biomechanical evaluation of fixation strength among different sizes of pedicle screws using the cortical bone trajectory: what is the ideal screw size for optimal fixation?

  • Experimental research - Spine
  • Published:
Acta Neurochirurgica Aims and scope Submit manuscript

Abstract

Background

The cortical bone trajectory (CBT) has attracted attention as a new minimally invasive technique for lumbar instrumentation by minimizing soft-tissue dissection. Biomechanical studies have demonstrated the superior fixation capacity of CBT; however, there is little consensus on the selection of screw size, and no biomechanical study has elucidated the most suitable screw size for CBT. The purpose of the present study was to evaluate the effect of screw size on fixation strength and to clarify the ideal size for optimal fixation using CBT.

Method

A total of 720 analyses on CBT screws with various diameters (4.5–6.5 mm) and lengths (25–40 mm) in simulations of 20 different lumbar vertebrae (mean age: 62.1 ± 20.0 years, 8 males and 12 females) were performed using a finite element method. First, the fixation strength of a single screw was evaluated by measuring the axial pullout strength. Next, the vertebral fixation strength of a paired-screw construct was examined by applying forces simulating flexion, extension, lateral bending, and axial rotation to the vertebra. Lastly, the equivalent stress value of the bone-screw interface was calculated.

Results

Larger-diameter screws increased the pullout strength and vertebral fixation strength and decreased the equivalent stress around the screws; however, there were no statistically significant differences between 5.5-mm and 6.5-mm screws. The screw diameter was a factor more strongly affecting the fixation strength of CBT than the screw fit within the pedicle (%fill). Longer screws significantly increased the pullout strength and vertebral fixation strength in axial rotation. The amount of screw length within the vertebral body (%length) was more important than the actual screw length, contributing to the vertebral fixation strength and distribution of stress loaded to the vertebra.

Conclusions

The fixation strength of CBT screws varied depending on screw size. The ideal screw size for CBT is a diameter larger than 5.5 mm and length longer than 35 mm, and the screw should be placed sufficiently deep into the vertebral body.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Baluch DA, Patel AA, Lullo B, Havey RM, Voronov LI, Nguyen NL, Carandang G, Ghanayem AJ, Patwardhan AG (2014) Effect of physiological loads on cortical and traditional pedicle screw fixation. Spine 39:E1297–E1302

    Article  PubMed  Google Scholar 

  2. Bianco RJ, Arnoux PJ, Wagnac E, Mac-Thiong JM, Aubin CĔ (2014) Minimizing pedicle screw pullout risks: a detailed biomechanical analysis of screw design and placement. J Spinal Disord Tech. doi:10.1097/BSD.0000000000000151

    PubMed  Google Scholar 

  3. Brantley AG, Mayfield JK, Koeneman JB, Clark KR (1994) The effects of pedicle screw fit: an in vitro study. Spine 19:1752–1758

    Article  CAS  PubMed  Google Scholar 

  4. Chen SI, Lin RM, Chang CH (2003) Biomechanical investigation of pedicle screw-vertebrae complex: a finite element approach using bonded and contact interface conditions. Med Eng Phys 25:275–282

    Article  PubMed  Google Scholar 

  5. Cheung KMC, Ruan D, Chan FL, Fang D (1994) Computed tomographic osteometry of asian lumbar pedicle. Spine 19:1495–1498

    Article  CAS  PubMed  Google Scholar 

  6. Halvorson TL, Kelly LA, Thomas KA, Whitecloud TS III, Cook SD (1994) Effects of bone mineral density on pedicle screw fixation. Spine 19:2415–2420

    Article  CAS  PubMed  Google Scholar 

  7. Hirano T, Hasegawa K, Takahashi HE, Uchiyama S, Hara T, Washio T, Sugiura T, Yokaichi M, Ikeda M (1997) Structural characteristics of the pedicle and its role in screw stability. Spine 22:2504–2510

    Article  CAS  PubMed  Google Scholar 

  8. Hsu CC, Chao CK, Wang JL, Hou SM, Tsai YT, Lin J (2005) Increase of pullout strength of spinal pedicle screws with conical core: biomechanical tests and finite element analyses. J Orthop Res 23:788–794

    Article  PubMed  Google Scholar 

  9. Imai K, Ohnishi I, Bessho M, Nakamura K (2006) Nonlinear finite element model predicts vertebral bone strength and fracture site. Spine 31:1789–1794

    Article  PubMed  Google Scholar 

  10. Karami KJ, Buckenmeyer LE, Kiapour AM, Kelkar PS, Goel VK, Demetropoulos CK, Soo TM (2014) Biomechanical evaluation of the pedicle screw insertion depth effect on screw stability under cyclic loading and subsequent pullout. J Spinal Disord Tech. doi:10.1097/BSD.0000000000000178

    Google Scholar 

  11. Keyak JH, Rossi SA, Jones KA, Skinner HB (1998) Prediction of femoral fracture load using automated finite element modeling. J Biomech 31:125–133

    Article  CAS  PubMed  Google Scholar 

  12. Krag MH, Beynnon BD, Pope MH, DeCoster TA (1989) Depth of insertion of transpedicular vertebral screws into human vertebrae: effect upon screw-vertebra interface strength. J Spinal Disord 1:287–294

    Google Scholar 

  13. Law M, Tencer AF, Anderson PA (1993) Caudo-cephalad loading of pedicle screws: biomechanisms of loosening and methods of augmentation. Spine 18:2438–2443

    Article  CAS  PubMed  Google Scholar 

  14. Lee GW, Son JH, Ahn MW, Kim HJ, Yeom JS (2015) The comparison of pedicle screw and cortical screw in posterior lumbar inter-boy fusion: a prospective randomized non-inferiority trial. Spine J. doi:10.1016/j.spinee.2015.02.038

    Google Scholar 

  15. Li B, Jiang B, Fu Z, Zhang D, Wang T (2004) Accurate determination of isthmus of lumbar pedicle: a morphometric study using reformatted computed tomographic imaging. Spine 29:2438–2444

    Article  PubMed  Google Scholar 

  16. Mahmoud A, Wakabayashi N, Takahashi H, Ohyama T (2005) Deflection fatigue of Ti-6Al-‘Nb, Co-Cr, and gold alloy cast clasps. J Prosthet Dent 93:183–188

    Article  CAS  PubMed  Google Scholar 

  17. Matsukawa K, Taguchi E, Yato Y, Imabayashi H, Hosogane N, Asazuma T, Nemoto K (2015) Evaluation of the fixation strength of pedicle screws using cortical bone trajectory: what is the ideal trajectory for optimal fixation? Spine 40:E873–E878

    Article  PubMed  Google Scholar 

  18. Matsukawa K, Yato Y, Imabayashi H, Hosogane N, Asazuma T, Nemoto K (2015) Biomechanical evaluation of fixation strength of lumbar pedicle screw using cortical bone trajectory: a finite element study. J Neurosurg Spine 23:471–478

    Article  PubMed  Google Scholar 

  19. Matsukawa K, Yato Y, Kato T, Imabayashi H, Asazuma T, Nemoto K (2014) In vivo analysis of insertional torque during pedicle screwing using cortical bone trajectory technique. Spine 39:E240–E245

    Article  PubMed  Google Scholar 

  20. Matsukawa K, Yato Y, Nemoto O, Imabayashi H, Asazuma T, Nemoto K (2013) Morphometric measurement of cortical bone trajectory for lumbar pedicle screw insertion using computed tomography. J Spinal Disord Tech 26:E248–E253

    Article  PubMed  Google Scholar 

  21. Matsuura Y, Giambini H, Ogawa Y, Fang Z, Thoreson AR, Yaszemski MJ, Lu L, An KN (2014) Specimen-specific nonlinear finite element modeling to predict vertebrae fracture loads after vertebroplasty. Spine 39:E1291–E1296

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  22. McKinley TO, McLain RF, Yerby SA, Sharkey NA, Sarigul-Klijn N, Smith TS (1999) Characteristics of pedicle screw loading: effect of surgical technique on intravertebral and intrapedicular bending moments. Spine 24:18–25

    Article  CAS  PubMed  Google Scholar 

  23. Mobbs RJ (2013) The “medio-latero-superior trajectory technique”: an alternative cortical trajectory for pedicle fixation. Orthop Surg 5:56–59

    Article  PubMed  Google Scholar 

  24. Perez-Orribo L, Kalb S, Reyes PM, Chang SW, Crawford NR (2013) Biomechanics of lumbar cortical screw-rod fixation versus pedicle screw-rod fixation with and without interbody support. Spine 38:635–641

    Article  PubMed  Google Scholar 

  25. Rodriguez A, Neal MT, Liu A, Somasundaram A, Hsu W, Branch CL Jr (2014) Novel placement of cortical bone trajectory screws in previously instrumented pedicles for adjacent-segment lumbar disease using CT image-guided navigation. Neurosurg Focus 36:E9

    Article  PubMed  Google Scholar 

  26. Santoni BG, Hynes RA, McGilvary KC, Rodriguez-Canessa G, Lyon AS, Henson MAW, Womack WJ, Puttlitz CM (2009) Cortical bone trajectory for lumbar pedicle screws. Spine J 9:366–373

    Article  CAS  PubMed  Google Scholar 

  27. Soshi S, Shiba R, Kondo H, Murota K (1991) An experimental study on transpedicular screw fixation in relation to osteoporosis of the lumbar spine. Spine 16:1335–1341

    Article  CAS  PubMed  Google Scholar 

  28. Ueno M, Sakai R, Tanaka K, Inoue G, Uchida K, Imura T, Saito W, Nakazawa T, Takahira N, Mabuchi K, Takaso M (2015) Should we use cortical bone screws for cortical bone trajectory? J Neurosurg Spine 22:416–421

    Article  PubMed  Google Scholar 

  29. Wu SS, Edwards WT, Yuan HA (1998) Stiffness between different directions of transpedicular screws and vertebra. Clin Biomech 13:S1–S8

    Article  Google Scholar 

  30. Zindrick MR, Wiltse LL, Widell EH, Thomas JC, Holland WR, Field BT, Spencer CW (1986) A biomechanical study of intrapeduncular screw fixation in the lumbosacral spine. Clin Orthop 203:99–112

    PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Orthopaedic Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan

    Keitaro Matsukawa, Hideaki Imabayashi, Naobumi Hosogane & Kazuhiro Chiba

  2. Department of Orthopaedic Surgery, National Hospital Organization, Murayama Medical Center, Musashimurayama, Tokyo, Japan

    Yoshiyuki Yato & Takashi Asazuma

  3. Department of Orthopaedic Surgery, Wajokai Eniwa Hospital, Eniwa, Hokkaido, Japan

    Yuichiro Abe

Authors
  1. Keitaro Matsukawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yoshiyuki Yato
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hideaki Imabayashi
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Naobumi Hosogane
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Yuichiro Abe
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Takashi Asazuma
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Kazuhiro Chiba
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Keitaro Matsukawa.

Ethics declarations

Conflicts of interest

None

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Matsukawa, K., Yato, Y., Imabayashi, H. et al. Biomechanical evaluation of fixation strength among different sizes of pedicle screws using the cortical bone trajectory: what is the ideal screw size for optimal fixation?. Acta Neurochir 158, 465–471 (2016). https://doi.org/10.1007/s00701-016-2705-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00701-016-2705-8

Keywords

Search

Navigation