European Spine Journal

, Volume 28, Issue 2, pp 362–369 | Cite as

Novel unilateral C1 double screw and ipsilateral C2 pedicle screw placement combined with contralateral laminar screw–rod fixation for atlantoaxial instability

  • Lei Shi
  • Kai Shen
  • Rui Deng
  • Zheng-Jian Yan
  • Kai-Lu Liang
  • Liang Chen
  • Zhen-Yong Ke
  • Zhong-Liang DengEmail author
Original Article



To investigate the anatomical and biomechanical feasibility of the unilateral C1 double screw [pedicle screw (PS) + lateral mass screw (LMS)] and ipsilateral C2 PS combined with contralateral C2 laminar screw (LS)-rod fixation for atlantoaxial instability by comparison with traditional posterior fixation methods.


Fifteen sets of complete dry bony specimens of atlas were used for morphometric analysis. The working length, width and thickness of the C1 PSs and LMSs were manually measured. Ten fresh-frozen cervical spines (C0–C7) were used to complete the range of motion (ROM) testing in their intact condition, under destabilization and after stabilization by the following procedures: unilateral C1–C2 PS rod fixation (Group A), bilateral C1–C2 PS rod fixation (Group B), and unilateral C1 double screw and ipsilateral C2 PS combined with contralateral C2 LS rod fixation (Group C).


The working thickness of the C1 PS was ≤ 3.5 mm in only one (1/15 = 6.7%) specimen. The other parameters were > 3.5 mm in all specimens. In the ROM test, all fixation groups showed significantly reduced flexibility in all directions compared with both the intact and destabilization groups. Further, Groups B and C showed better stability in all directions than Group A. However, no significant differences were observed between Groups B and C.


The C1 unilateral lateral mass could mostly contain two screws(PS + LMS) with diameters ≤ 3.5 mm. The novel technique of unilateral C1 double screw and ipsilateral C2 PS combined with contralateral C2 LS rod fixation provided better stability than unilateral PS rod fixation and similar as bilateral PS rod fixation. Therefore, it is a feasible salvage method that provides a new insight into atlantoaxial instability.

Graphical abstract

These slides can be retrieved under Electronic Supplementary Material.


Atlantoaxial instability Morphometric analysis Biomechanics C1 double screw Unilateral fixation 



The study was supported by the national nature science foundation of China (No. 81301573), natural science foundation of Chongqing (No. cstc2013jcyjA10090), the special foundation for social safeguard and scientific innovation of Chongqing (No. cstc2016shms-ztzx10001-6), Science and technology foundation of Yuzhong district in Chongqing (No. 20160131), Chongqing research and innovation project of graduate students(No.YB17112).

Compliance with ethical standards

Conflict of interest

All authors have declared that they have no conflicts of interest.

Supplementary material

586_2018_5853_MOESM1_ESM.pptx (1.1 mb)
Supplementary material 1 (PPTX 1090 kb)


  1. 1.
    Goel A, Laheri V (1994) Plate and screw fixation for atlanto-axial subluxation. Acta Neurochir 129(1–2):47–53CrossRefGoogle Scholar
  2. 2.
    Harms J, Melcher RP (2001) Posterior C1–C2 fusion with polyaxial screw and rod fixation. Spine (Phila Pa 1976) 23(22):2467–2471CrossRefGoogle Scholar
  3. 3.
    Resnick DK, Benzel EC (2002) C1–C2 pedicle screw fixation with rigid cantilever beam construct: case report and technical note. Neurosurgery 50(2):426–428Google Scholar
  4. 4.
    Fensky F, Kueny RA, Sellenschloh K et al (2014) Biomechanical advantage of C1 pedicle screws over C1 lateral mass screws: a cadaveric study. Eur Spine J 23(4):724–731CrossRefGoogle Scholar
  5. 5.
    Eck JC, Walker MP, Currier BL, Chen Q, Yaszemski MJ, An KN (2007) Biomechanical comparison of unicortical versus bicortical C1 lateral mass screw fixation. J Spin Disord Tech 20(7):505–508CrossRefGoogle Scholar
  6. 6.
    Ma XY, Yin QS, Wu ZH et al (2009) C1 pedicle screws versus C1 lateral mass screws: comparisons of pullout strengths and biomechanical stabilities. Spine (Phila Pa 1976) 34(4):371–377CrossRefGoogle Scholar
  7. 7.
    Richter M, Schmidt R, Claes L, Puhl W, Wilke HJ (2002) Posterior atlantoaxial fixation: biomechanical in vitro comparison of six different techniques. Spine (Phila Pa 1976) 27(16):1724–1732CrossRefGoogle Scholar
  8. 8.
    Paik SC, Chun HJ, Bak KH, Ryu J, Choi KS (2015) Unilateral C1 Lateral Mass and C2 Pedicle Screw Fixation for Atlantoaxial Instability in Rheumatoid Arthritis Patients: Comparison with the Bilateral Method. J Korean Neurosurg Soc 57(6):460–464CrossRefGoogle Scholar
  9. 9.
    Bhatia N, Rama A, Sievers B et al (2017) Biomechanical evaluation of unilateral versus bilateral C1 lateral mass-C2 intralaminar fixation. Global Spine J 7(3):239–245CrossRefGoogle Scholar
  10. 10.
    Tan M, Wang H, Wang Y et al (2003) Morphometric evaluation of screw fixation in atlas via posterior arch and lateral mass. Spine (Phila Pa 1976) 28(9):888–895Google Scholar
  11. 11.
    Shen K, Deng Z, Yang J, Liu C, Zhang R (2017) Biomechanical study of novel unilateral C1 posterior arch screws and C2 laminar screws combined with an ipsilateral crossed C1–C2 pedicle screw-rod fixation for atlantoaxial instability. Arch Orthop Trauma Surg 137(10):1349–1355CrossRefGoogle Scholar
  12. 12.
    Calisaneller T, Yilmaz C, Ozdemir O, Caner H (2008) Posterior atlantal lateral mass fixation technique with polyaxial screw and rod fixation system. Turkish Neurosurg 18(2):142–148Google Scholar
  13. 13.
    Chen JF, Wu CT, Lee SC, Lee ST (2005) Posterior atlantoaxial transpedicular screw and plate fixation. J Neurosurg Spine 2(3):386–392CrossRefGoogle Scholar
  14. 14.
    Yoon KW, Ko JH, Cho CS, Lee SK, Kim YJ, Kim YJ (2013) Endovascular treatment of vertebral artery injury during cervical posterior fusion (C1 lateral mass screw). A case report. Interv Neuroradiol 19(3):370–376CrossRefGoogle Scholar
  15. 15.
    Lall R, Patel NJ, Resnick DK (2010) A review of complications associated with craniocervical fusion surgery. Neurosurgery 67(5):1396–1403CrossRefGoogle Scholar
  16. 16.
    Wright NM (2004) Posterior C2 fixation using bilateral, crossing C2 laminar screws: case series and technical note. J Spinal Disord Tech 17(2):158–162CrossRefGoogle Scholar
  17. 17.
    Du S, Ni B, Lu X et al (2017) Application of unilateral C2 translaminar screw in the treatment for atlantoaxial instability as an alternative or salvage of pedicle screw fixation. World Neurosurg 97:86–92CrossRefGoogle Scholar
  18. 18.
    Christensen DM, Eastlack RK, Lynch JJ, Yaszemski MJ, Currier BL (2007) C1 anatomy and dimensions relative to lateral mass screw placement. Spine (Phila Pa 1976) 32(8):844–848CrossRefGoogle Scholar
  19. 19.
    Seal C, Zarro C, Gelb D, Ludwig S (2009) C1 lateral mass anatomy: Proper placement of lateral mass screws. J Spinal Disord Tech 22(7):516–523CrossRefGoogle Scholar
  20. 20.
    Gupta T (2008) Cadaveric morphometric anatomy of C-1 vertebra in relation to lateral mass screw placement. Surg Radiol Anat 30(7):589–593CrossRefGoogle Scholar
  21. 21.
    Simsek S, Yigitkanli K, Seçkin H et al (2009) Ideal screw entry point and projection angles for posterior lateral mass fixation of the atlas: an anatomical study. Eur Spine J 18(9):1321–1325CrossRefGoogle Scholar
  22. 22.
    Ma XY, Yin QS, Wu ZH, Xia H, Liu JF, Zhong SZ (2007) Anatomic considerations for the pedicle screw placement in the first cervical vertebra. Spine (Phila Pa 1976) 30(13):1519–1523CrossRefGoogle Scholar
  23. 23.
    Lee MJ, Cassinelli E, Riew KD (2006) The feasibility of inserting atlas lateral mass screws via the posterior arch. Spine 31(24):2798–2801CrossRefGoogle Scholar
  24. 24.
    Zhang XL, Huang DG, Wang XD et al (2017) The feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus: a retrospective analysis of eleven patients. Eur Spine J 26(4):1058–1063CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Lei Shi
    • 1
    • 2
  • Kai Shen
    • 1
    • 3
  • Rui Deng
    • 1
  • Zheng-Jian Yan
    • 1
    • 2
  • Kai-Lu Liang
    • 1
    • 2
  • Liang Chen
    • 1
    • 2
  • Zhen-Yong Ke
    • 1
    • 2
  • Zhong-Liang Deng
    • 1
    • 2
    Email author
  1. 1.Department of OrthopedicsThe Second Affiliated Hospital of Chongqing Medical UniversityChongqingPeople’s Republic of China
  2. 2.Geriatric Clinical Research Center of ChongqingChongqingPeople’s Republic of China
  3. 3.Department of OrthopedicsChongqing General HospitalChongqingPeople’s Republic of China

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