Skip to main content

Analysis of the risk factors for increasing cervical sagittal vertical axis after cervical laminoplasty for cervical spondylotic myelopathy



The cervical sagittal vertical axis (cSVA) as another aspect of cervical alignment been recognized as one of the important factors affecting the pain and disability outcomes of cervical spine surgery. The purpose of the present study was to analyze the risk factors for increasing cSVA after cervical laminoplasty for cervical spondylotic myelopathy (CSM).

Materials and methods

This retrospective study included 110 consecutive patients (68 males and 42 females, average age 72.6 years) who underwent laminoplasty for CSM between January 2007 and June 2018. We recorded the operative time, blood loss, Japanese Orthopaedic Association (JOA) score and the recovery rate. Radiological measurements were performed to analyze the following parameters: pre- and 1-year postoperative McGregor’s slope (McGS), occiput to C2 Cobb angle (O–C2 angle), C2–C7 Cobb angle (C2–7 angle), T1-slope (T1S), C2–7 SVA (cSVA) and calculated the change (Δ). Patients were divided into two groups according to whether ΔcSVA was positive or negative. We also used Spearman's correlation coefficient and multiple regression analysis.


ΔC2–7 angle, ΔT1S—preoperative C2–7 angle, ΔO–C2 angle were different between the two groups significantly. Correlation analysis between the ΔcSVA and the various sagittal parameters showed some independent explanatory factors including the ΔC2–7 angle (r = − 0.25, p = 0.010), T1S—preoperative C2–7 angle (r = − 0.28, p = 0.004), postoperative O–C2 angle (r = 0.26, p = 0.007), ΔO–C2 angle (r = 0.37, p = 0.001). Multiple regression analysis revealed that ΔcSVA was associated with the T1S—preoperative C2–7 angle (β = − 0.25, p = 0.034) and ΔO–C2 angle (β = 0.32, p = 0.001).


The imbalance between T1S and preoperative C2–7 angle influences the change of cSVA after cervical laminoplasty. If cSVA increases postoperatively, the O–C2 angle increases to compensate and maintain the horizontal gaze.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3


  1. Braly BA, Lunardini D, Cornett C, Donaldson WF (2012) Operative treatment of cervical myelopathy: cervical laminoplasty. Adv Orthop 2012:508534

    Article  Google Scholar 

  2. Petraglia AL, Srinivasan V, Coriddi M, Whitbeck MG, Maxwell JT, Silberstein HJ (2010) Cervical laminoplasty as a management option for patients with cervical spondylotic myelopathy: a series of 40 patients. Neurosurgery 67:272–277

    Article  Google Scholar 

  3. Matz PG, Anderson PA, Groff MW, Heary RF, Holly LT, Kaiser MG et al (2009) Cervical laminoplasty for the treatment of cervical degenerative myelopathy. J Neurosurg Spine 11:157–169

    Article  Google Scholar 

  4. Kimura I, Shingu H, Nasu Y (1995) Long-term follow-up of cervical spondylotic myelopathy treated by canal-expansive laminoplasty. J Bone Jt Surg Br 77:956–961

    CAS  Article  Google Scholar 

  5. Suda K, Abumi K, Ito M, Shono Y, Kaneda K, Fujiya M (2003) Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy. Spine (Phila Pa 1976) 28:1258–1262

    Google Scholar 

  6. Tang JA, Scheer JK, Smith JS, Deviren V, Bess S, Hart RA et al (2015) The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery. Neurosurgery 76(Suppl 1):S14–S21

    Article  Google Scholar 

  7. Oe S, Togawa D, Nakai K, Yamada T, Arima H, Banno T et al (2015) The influence of age and sex on cervical spinal alignment among volunteers aged over 50. Spine (Phila Pa 1976) 40:1487–1494

    Article  Google Scholar 

  8. Protopsaltis TS, Scheer JK, Terran JS, Smith JS, Hamilton DK, Kim HJ et al (2015) How the neck affects the back: changes in regional cervical sagittal alignment correlate to HRQOL improvement in adult thoracolumbar deformity patients at 2-year follow-up. J Neurosurg Spine 23:153–158

    Article  Google Scholar 

  9. Sakai K, Yoshii T, Hirai T, Arai Y, Torigoe I, Tomori M et al (2016) Cervical sagittal imbalance is a predictor of kyphotic deformity after laminoplasty in cervical spondylotic myelopathy patients without preoperative kyphotic alignment. Spine (Phila Pa 1976) 41:299–305

    Article  Google Scholar 

  10. Taniyama T, Hirai T, Yamada T, Yuasa M, Enomoto M, Yoshii T et al (2013) Modified K-line in magnetic resonance imaging predicts insufficient decompression of cervical laminoplasty. Spine (Phila Pa 1976) 38:496–501

    Article  Google Scholar 

  11. Taniyama T, Hirai T, Yoshii T, Yamada T, Yasuda H, Saito M et al (2014) Modified K-line in magnetic resonance imaging predicts clinical outcome in patients with nonlordotic alignment after laminoplasty for cervical spondylotic myelopathy. Spine (Phila Pa 1976) 39:E1261–E1268

    Article  Google Scholar 

  12. Hirai T, Yoshii T, Inose H, Yuasa M, Yamada T, Ushio S et al (2019) Is modified K-line a powerful tool of surgical decision making for patients with cervical spondylotic myelopathy? Clin Spine Surg 32:351–356

    Article  Google Scholar 

  13. Takeuchi K, Yokoyama T, Aburakawa S, Saito A, Numasawa T, Iwasaki T et al (2005) Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3–C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis. Spine (Phila Pa 1976) 30:2544–2549

    Article  Google Scholar 

  14. Hirabayashi K, Miyakawa J, Satomi K, Maruyama T, Wakano K (1981) Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament. Spine (Phila Pa 1976) 6:354–364

    CAS  Article  Google Scholar 

  15. Kim B, Yoon DH, Ha Y, Yi S, Shin DA, Lee CK et al (2016) Relationship between T1 slope and loss of lordosis after laminoplasty in patients with cervical ossification of the posterior longitudinal ligament. Spine J 16:219–225

    Article  Google Scholar 

  16. Khalil N, Bizdikian AJ, Bakouny Z, Salameh M, Bou Zeid N, Yared F et al (2018) Cervical and postural strategies for maintaining horizontal gaze in asymptomatic adults. Eur Spine J 27:2700–2709

    Article  Google Scholar 

  17. Miyamoto H, Hashimoto K, Ikeda T, Akagi M (2017) Effect of correction surgery for cervical kyphosis on compensatory mechanisms in overall spinopelvic sagittal alignment. Eur Spine J 26:2380–2385

    Article  Google Scholar 

  18. Protopsaltis TS, Lafage R, Vira S, Sciubba D, Soroceanu A, Hamilton K et al (2017) Novel angular measures of cervical deformity account for upper cervical compensation and sagittal alignment. Clin Spine Surg 30:E959–E967

    Article  Google Scholar 

  19. Diebo BG, Challier V, Henry JK, Oren JH, Spiegel MA, Vira S et al (2016) Predicting cervical alignment required to maintain horizontal gaze based on global spinal alignment. Spine (Phila Pa 1976) 41:1795–1800

    Article  Google Scholar 

  20. Le Huec JC, Demezon H, Aunoble S (2015) Sagittal parameters of global cervical balance using EOS imaging: normative values from a prospective cohort of asymptomatic volunteers. Eur Spine J 24:63–71

    Article  Google Scholar 

  21. Ota M, Neo M, Aoyama T, Ishizaki T, Fujibayashi S, Takemoto M et al (2011) Impact of the O-C2 angle on the oropharyngeal space in normal patients. Spine (Phila Pa 1976) 36:E720–E726

    Article  Google Scholar 

  22. Lee SH, Kim KT, Seo EM, Suk KS, Kwack YH, Son ES (2012) The influence of thoracic inlet alignment on the craniocervical sagittal balance in asymptomatic adults. J Spinal Disord Tech 25:E41–E47

    Article  Google Scholar 

  23. Kim SW, Kim TH, Bok DH, Jang C, Yang MH, Lee S et al (2018) Analysis of cervical spine alignment in currently asymptomatic individuals: prevalence of kyphotic posture and its relationship with other spinopelvic parameters. Spine J 18:797–810

    Article  Google Scholar 

  24. Tang JA, Scheer JK, Smith JS, Deviren V, Bess S, Hart RA et al (2012) The impact of standing regional cervical sagittal alignment on outcomes in posterior cervical fusion surgery. Neurosurgery 71:662–669

    Article  Google Scholar 

  25. Ames CP, Smith JS, Eastlack R, Blaskiewicz DJ, Shaffrey CI, Schwab F et al (2015) Reliability assessment of a novel cervical spine deformity classification system. J Neurosurg Spine 23:673–683

    Article  Google Scholar 

  26. Knott PT, Mardjetko SM, Techy F (2010) The use of the T1 sagittal angle in predicting overall sagittal balance of the spine. Spine J 10:994–998

    Article  Google Scholar 

  27. Nunez-Pereira S, Hitzl W, Bullmann V, Meier O, Koller H (2015) Sagittal balance of the cervical spine: an analysis of occipitocervical and spinopelvic interdependence, with C-7 slope as a marker of cervical and spinopelvic alignment. J Neurosurg Spine 23:16–23

    Article  Google Scholar 

  28. Iorio J, Lafage V, Lafage R, Henry JK, Stein D, Lenke LG et al (2018) The effect of aging on cervical parameters in a normative north American population. Global Spine J 8:709–715

    Article  Google Scholar 

  29. Schwab F, Ungar B, Blondel B, Buchowski J, Coe J, Deinlein D et al (2012) Scoliosis research society-Schwab adult spinal deformity classification: a validation study. Spine (Phila Pa 1976) 37:1077–1082

    Article  Google Scholar 

  30. Smith JS, Shaffrey CI, Lafage V, Blondel B, Schwab F, Hostin R et al (2012) Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy. J Neurosurg Spine 17:300–307

    Article  Google Scholar 

  31. Lee DH, Ha JK, Chung JH, Hwang CJ, Lee CS, Cho JH (2016) A retrospective study to reveal the effect of surgical correction of cervical kyphosis on thoraco-lumbo-pelvic sagittal alignment. Eur Spine J 25:2286–2293

    Article  Google Scholar 

  32. Hashimoto K, Miyamoto H, Ikeda T, Akagi M (2018) Radiologic features of dropped head syndrome in the overall sagittal alignment of the spine. Eur Spine J 27:467–474

    Article  Google Scholar 

  33. Mizutani J, Verma K, Endo K, Ishii K, Abumi K, Yagi M et al (2018) Global spinal alignment in cervical kyphotic deformity: the importance of head position and thoracolumbar alignment in the compensatory mechanism. Neurosurgery 82:686–694

    Article  Google Scholar 

Download references




This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Masashi Miyazaki.

Ethics declarations

Conflict of interest

Each author certifies that he or a member of their immediate family has no commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements) that might pose a conflict of interest in connection with the submitted article.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Abe, T., Miyazaki, M., Ishihara, T. et al. Analysis of the risk factors for increasing cervical sagittal vertical axis after cervical laminoplasty for cervical spondylotic myelopathy. Arch Orthop Trauma Surg 142, 553–560 (2022).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Cervical spondylotic myelopathy
  • Cervical spine
  • Laminoplasty
  • Myelopathy
  • Quality of life
  • Sagittal alignment
  • Spinal cord compression