Skip to main content

Advertisement

Log in

Usefulness of the preoperative thoracic inlet angle in comparison to the T1 slope for predicting cervical kyphosis after laminoplasty

  • Original Article
  • Published:
European Spine Journal Aims and scope Submit manuscript

Abstract

Purpose

Thoracic inlet angle (TIA) is a sagittal radiographic parameter with a constant value regardless of posture and is significantly correlated with the sagittal balance of the cervical spine. However, the practical use of TIA has not been studied. This study aimed to investigate the usefulness of the preoperative TIA for predicting the development of kyphotic deformity after cervical laminoplasty in comparison to the preoperative T1 slope (T1S).

Methods

A total of 98 patients who underwent cervical laminoplasty without preoperative kyphotic alignment were included (mean age, 73.7 years; 41.8% female). Radiography was evaluated before surgery and at the 2-year follow-up examination. The cervical sagittal parameters were measured on standing radiographs, and the TIA was measured on T2-weighted MRI in a supine position. Cervical alignment with a C2–C7 angle of ≥ 0° was defined as lordosis, and that with an angle of < 0° was defined as kyphosis.

Results

Postoperative kyphosis occurred in 11 patients (11.2%). Preoperatively, the kyphosis group showed significantly lower values in the T1S (23.5° vs. 30.3°, p = 0.034) and TIA (76.1° vs. 81.8°, p = 0.042). We performed ROC curve analysis to clarify the impact of the preoperative TIA and T1S on kyphotic deformity after laminoplasty. The optimal cutoff angles for TIA and T1S were 68° and 19°, respectively, with similar diagnostic accuracy.

Conclusion

This study demonstrated the clinical utility of the preoperative TIA for predicting the risk of postoperative kyphotic deformity after cervical laminoplasty. These findings suggest the importance of the preoperative assessment of thoracic inlet alignment in cervical spine surgery.

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

Access this article

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

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Lee SH, Kim KT, Seo EM et al (2012) The influence of thoracic inlet alignment on the craniocervical sagittal balance in asymptomatic adults. J Spinal Disord Tech 25(2):E41–E47. https://doi.org/10.1097/BSD.0b013e3182396301

    Article  PubMed  Google Scholar 

  2. Xing R, Zhou G, Chen Q et al (2017) MRI to measure cervical sagittal parameters: a comparison with plain radiographs. Arch Orthop Trauma Surg 137(4):451–455. https://doi.org/10.1007/s00402-017-2639-5

    Article  PubMed  Google Scholar 

  3. Cheng J, Liu P, Sun D et al (2019) Correlation of cervical and thoracic inlet sagittal parameters by MRI and radiography in patients with cervical spondylosis. Medicine 98(7):e14393. https://doi.org/10.1097/MD.0000000000014393

    Article  PubMed  PubMed Central  Google Scholar 

  4. Lee SH, Son ES, Seo EM et al (2015) Factors determining cervical spine sagittal balance in asymptomatic adults: correlation with spinopelvic balance and thoracic inlet alignment. Spine J 15(4):705–712. https://doi.org/10.1016/j.spinee.2013.06.059

    Article  PubMed  Google Scholar 

  5. Suk KS, Kim KT, Lee JH et al (2007) Sagittal alignment of the cervical spine after the laminoplasty. Spine 32(23):E656–E660. https://doi.org/10.1097/BRS.0b013e318158c573

    Article  PubMed  Google Scholar 

  6. Suda K, Abumi K, Ito M et al (2003) Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy. Spine 28(12):1258–1262. https://doi.org/10.1097/01.BRS.0000065487.82469.D9

    Article  PubMed  Google Scholar 

  7. Scheer JK, Tang JA, Smith JS et al (2013) Cervical spine alignment, sagittal deformity, and clinical implications: a review. J Neurosurg Spine 19(2):141–159. https://doi.org/10.3171/2013.4.SPINE12838

    Article  PubMed  Google Scholar 

  8. Roguski M, Benzel EC, Curran JN et al (2014) Postoperative cervical sagittal imbalance negatively affects outcomes after surgery for cervical spondylotic myelopathy. Spine 39(25):2070–2077. https://doi.org/10.1097/BRS.0000000000000641

    Article  PubMed  PubMed Central  Google Scholar 

  9. Tamai K, Buser Z, Paholpak P et al (2018) Can C7 slope substitute the t1 slope? An analysis using cervical radiographs and kinematic MRIs. Spine 43(7):520–525. https://doi.org/10.1097/BRS.0000000000002371

    Article  PubMed  Google Scholar 

  10. Machino M, Ando K, Kobayashi K et al (2020) Postoperative kyphosis in cervical spondylotic myelopathy: cut-off preoperative angle for predicting the postlaminoplasty kyphosis. Spine 45(10):641–648. https://doi.org/10.1097/BRS.0000000000003345

    Article  PubMed  Google Scholar 

  11. Choi I, Roh SW, Rhim SC, Jeon SR (2018) The time course of cervical alignment after cervical expansive laminoplasty: determining optimal cut-off preoperative angle for predicting postoperative kyphosis. Medicine 97(47):e13335. https://doi.org/10.1097/MD.0000000000013335

    Article  PubMed  PubMed Central  Google Scholar 

  12. Duetzmann S, Cole T, Ratliff JK (2015) Cervical laminoplasty developments and trends, 2003–2013: a systematic review. J Neurosurg Spine 23(1):24–34. https://doi.org/10.3171/2014.11.SPINE14427

    Article  PubMed  Google Scholar 

  13. Takasawa E, Sorimachi Y, Iizuka Y et al (2019) Risk factors for rapidly progressive neurological deterioration in cervical spondylotic myelopathy. Spine 44(12):E723–E730. https://doi.org/10.1097/BRS.0000000000002969

    Article  PubMed  Google Scholar 

  14. Kanda Y (2013) Investigation of the freely available easy-to-use software “EZR” for medical statistics. Bone Marrow Transpl 48(3):452–458. https://doi.org/10.1038/bmt.2012.244

    Article  CAS  Google Scholar 

  15. Ames CP, Blondel B, Scheer JK et al (2013) Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy. Spine 38(22 Suppl 1):S149–S160. https://doi.org/10.1097/BRS.0b013e3182a7f449

    Article  PubMed  Google Scholar 

  16. Iyer S, Nemani VM, Nguyen J et al (2016) Impact of cervical sagittal alignment parameters on neck disability. Spine 41(5):371–377. https://doi.org/10.1097/BRS.0000000000001221

    Article  PubMed  Google Scholar 

  17. Takasawa E, Iizuka Y, Ishiwata S et al (2023) Impact of the preoperative nutritional status on postoperative kyphosis in geriatric patients undergoing cervical laminoplasty. Eur Spine J 32(1):374–381. https://doi.org/10.1007/s00586-022-07481-8

    Article  PubMed  Google Scholar 

  18. Sakai K, Yoshii T, Hirai T et al (2016) Cervical sagittal imbalance is a predictor of kyphotic deformity after laminoplasty in cervical spondylotic myelopathy patients without preoperative kyphotic alignment. Spine 41(4):299–305. https://doi.org/10.1097/BRS.0000000000001206

    Article  PubMed  Google Scholar 

  19. 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(11):994–998. https://doi.org/10.1016/j.spinee.2010.08.031

    Article  PubMed  Google Scholar 

  20. Kim TH, Lee SY, Kim YC et al (2013) T1 slope as a predictor of kyphotic alignment change after laminoplasty in patients with cervical myelopathy. Spine 38(16):E992–E997. https://doi.org/10.1097/BRS.0b013e3182972e1b

    Article  PubMed  Google Scholar 

  21. Hyun SJ, Kim KJ, Jahng TA et al (2016) Relationship between t1 slope and cervical alignment following multilevel posterior cervical fusion surgery: impact of T1 slope minus cervical lordosis. Spine 41(7):E396–E402. https://doi.org/10.1097/BRS.0000000000001264

    Article  PubMed  Google Scholar 

  22. Park BJ, Gold CJ, Woodroffe RW et al (2021) What is the most accurate substitute for an invisible T1 slope in cervical radiographs? A comparative study of a novel method with previously reported substitutes. J Neurosurg Spine. https://doi.org/10.3171/2021.8.SPINE21901

    Article  PubMed  PubMed Central  Google Scholar 

  23. Lee SH, Hyun SJ, Jain A (2020) Cervical sagittal alignment: literature review and future directions. Neurospine 17(3):478–496. https://doi.org/10.14245/ns.2040392.196

    Article  PubMed  PubMed Central  Google Scholar 

  24. Yang K, Li XY, Wang Y et al (2022) Relationship between TIA minus C0–7 angle and C2–7 SVA: analysis of 113 symptomatic patients. BMC Musculoskelet Disord 23(1):338. https://doi.org/10.1186/s12891-022-05301-0

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Ling FP, Chevillotte T, Leglise A et al (2018) Which parameters are relevant in sagittal balance analysis of the cervical spine? A Lit Rev Eur Spine J 27(Suppl 1):8–15. https://doi.org/10.1007/s00586-018-5462-y

    Article  Google Scholar 

Download references

Acknowledgement

Not applicable.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Eiji Takasawa.

Ethics declarations

Conflict of interest

None of the authors has any potential conflict of interest.

Additional information

Publisher's Note

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

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Takakura, K., Takasawa, E., Mieda, T. et al. Usefulness of the preoperative thoracic inlet angle in comparison to the T1 slope for predicting cervical kyphosis after laminoplasty. Eur Spine J 33, 1179–1186 (2024). https://doi.org/10.1007/s00586-023-08095-4

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00586-023-08095-4

Keywords

Navigation