Skip to main content

Advertisement

SpringerLink
Log in

Intra- and inter-observer reliability of Cobb angle measurements in patients with adolescent idiopathic scoliosis

  • Case Series
  • Published:
Spine Deformity Aims and scope Submit manuscript

Abstract

Purpose

The Cobb angle method is used to determine the severity of scoliosis. Therapeutic decisions for adolescent idiopathic scoliosis (AIS) are guided by the Cobb angle. Therefore, high reliability is crucial. The objective of this study was to determine the intra- and inter-observer reliability of the digital Cobb angle measurements and the definition of end vertebrae in patients with AIS. Moreover, the influence of the observer’s medical specialty and experience on Cobb angle measurement was evaluated.

Methods

Intra- and inter-observer reliability of the digital Cobb angle and end vertebrae is assessed in postero-anterior radiographs of 39 patients with AIS. Measurements were performed blinded and twice by six observers, with a two to 3 week interval. Intra- and inter-observer reliability was analysed by means of intraclass correlation coefficients (ICC).

Results

Both intra- and inter-observer reliability analyses resulted in ICC’s higher than 0.864 for the Cobb angle and definition of end vertebrae. In addition, for the observer’s experience and medical specialty group the inter-observer ICC’s were higher than 0.984. The average inter-observer variability for the Cobb angle were 3°, and 1.1–1.6 levels for the cranial and caudal end vertebrae selection. The variability in measured Cobb angle was 1° for the experience group and 2° for the medical specialty group. Cronbach’s alpha varied from 0.990 to 0.996. Bland–Altman plots showed moderate variation with a few outliers.

Conclusions

The digital Cobb angle measurement as well as the definition of end vertebrae show excellent reliability. According to our results, medical specialty and experience do not affect Cobb angle measurements and definition of end vertebrae.

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

Similar content being viewed by others

References

  1. Konieczny MR, Senyurt H, Krauspe R (2013) Epidemiology of adolescent idiopathic scoliosis. J Child Orthop 7(1):3–9

    Article  Google Scholar 

  2. Canavese F, Turcot K, De Rosa V et al (2011) Cervical spine sagittal alignment variations following posterior spinal fusion and instrumentation for adolescent idiopathic scoliosis. Eur Spine J 20(7):1141–1148

    Article  Google Scholar 

  3. Théroux J, Le-May S, Hebert JJ et al (2017) Back pain prevalence is associated with curve-type and severity in adolescents with idiopathic scoliosis. Spine (Phila Pa 1976) 42(15):914–919

    Article  Google Scholar 

  4. Horne JP, Flannery R, Usman S (2014) Adolescent idiopathic scoliosis: diagnosis and management. Am Fam Phys 89(3):193–198

    Google Scholar 

  5. Griffet J, Leroux MA, Badeaux J et al (2000) Relationship between gibbosity and Cobb angle during treatment of idiopathic scoliosis with the SpineCor brace. Eur Spine J 9(6):516–522

    Article  CAS  Google Scholar 

  6. Goldberg CJ, Dowling FE, Fogarty EE (1993) Adolescent idiopathic scoliosis: is rising growth rate the triggering factor in progression? Eur Spine J 2(1):29–36

    Article  CAS  Google Scholar 

  7. Biondi J, Weiner DS, Bethem D et al (1985) Correlation of Risser sign and bone age determination in adolescent idiopathic scoliosis. J Paediatr Orthop 5(6):697–701

    Article  CAS  Google Scholar 

  8. Cobb JR (1948) Outlines for the study of scoliosis. Instr Course Lect 5:261–272

    Google Scholar 

  9. Langensiepen S, Semler O, Sobottke R et al (2013) Measuring procedures to determine the Cobb angle in idiopathic scoliosis: a systematic review. Eur Spine J 22(11):2360–2371

    Article  CAS  Google Scholar 

  10. Gstoettner M, Sekyra K, Walochnik N et al (2007) Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools. Eur Spine J 16(10):1587–1592

    Article  Google Scholar 

  11. Lonstein JE, Carlson JM (1984) The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am 66(7):1061–1071

    Article  CAS  Google Scholar 

  12. Lechner R, Putzer D, Dammerer D et al (2017) Comparison of two- and three-dimensional measurement of the Cobb angle in scoliosis. Int Orthop 41(5):957–962

    Article  Google Scholar 

  13. Aubin CE, Bellefleur C, Joncas J et al (2011) Reliability and accuracy analysis of a new semiautomatic radiographic measurement software in adult scoliosis. Spine (Phila Pa 1976) 36(12):780–790

    Article  Google Scholar 

  14. Zhang J, Lou E, Shi X et al (2010) A computer-aided Cobb angle measurement method and its reliability. J Spinal Disord Tech 23(6):383–387

    Article  Google Scholar 

  15. McAlinden C, Khadka J, Pesudovs K (2015) Precision (repeatability and reproducibility) studies and sample-size calculation. J Cataract Refract Surg 41(12):2598–2604

    Article  Google Scholar 

  16. Field A (2009) Discovering statistics using SPSS, 3rd edn. Sage Publications Ltd, London

    Google Scholar 

  17. Koo TK, Li MY (2016) A Giudeline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med 15:155–163

    Article  Google Scholar 

  18. Bland JM, Altman DG (1997) Statistic notes Cronbach’s alpha. BMJ 314:572

    Article  CAS  Google Scholar 

  19. Jones M, Dobson A, O’Brian S (2011) A graphical method for assessing agreement with the mean between multiple observers using continuous measures. Int J Epidemiol 40:1308–1313

    Article  Google Scholar 

  20. Carman DL, Browne RH, Birch JG (1990) Measurement of scoliosis and kyphosis radiographs. Intraobserver and interobserver variation. J Bone Joint Surg Am 72(3):328–333

    Article  CAS  Google Scholar 

  21. Morrissy RT, Goldsmith GS, Hall EC et al (1990) Measurement of the Cobb angle on radiographs of patients who have scoliosis. Evaluation of intrinsic error. J Bone Joint Surg Am 72(3):320–327

    Article  CAS  Google Scholar 

  22. Wu W, Liang J, Du Y et al (2014) Reliability and reproducibility analysis of the Cobb angle and assessing sagittal plane by computer-assisted and manual measurement tools. BMC Musculoskelet Disord 15:33

    Article  Google Scholar 

  23. Villemure I, Aubin CE, Grimard G et al (1976) Progression of vertebral and spinal three-dimensional deformities in adolescent idiopathic scoliosis: a longitudinal study. Spine 26(20):2244–2250

    Article  Google Scholar 

Download references

Acknowledgements

We would like to thank Helene Gendera, Dave van Iersel and Sander Sassen for their contribution to this study.

Funding

No funds, grants, or other support was received.

Author information

Authors and Affiliations

  1. Orthopaedic Department, VieCuri Medical Centre, Venlo, The Netherlands

    F. G. Prestigiacomo, M. H. H. M. Hulsbosch, V. E. J. Bruls & J. J. Nieuwenhuis

Authors
  1. F. G. Prestigiacomo
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. H. H. M. Hulsbosch
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. V. E. J. Bruls
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. J. J. Nieuwenhuis
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

All authors contributed to the study conception and design. Material preparation and data collection were performed by FGP and JJN. Analysis was performed by all authors. The first draft of the manuscript was written by FGP, and all authors were commented on the previous versions of the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to F. G. Prestigiacomo.

Ethics declarations

Conflicts of interest

The authors have no conflicts of interest to declare which are relevant to the content of this article.

Ethical approval

Ethical approval was waived by the local Ethics Committee of University A in view of the retrospective nature of the study, and all the procedures being performed were part of the routine care.

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

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Prestigiacomo, F.G., Hulsbosch, M.H.H.M., Bruls, V.E.J. et al. Intra- and inter-observer reliability of Cobb angle measurements in patients with adolescent idiopathic scoliosis. Spine Deform 10, 79–86 (2022). https://doi.org/10.1007/s43390-021-00398-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s43390-021-00398-0

Keywords

Search

Navigation