Skip to main content
Log in

Selection of Fusion Levels in Adolescent Idiopathic Scoliosis

  • Published:
Current Reviews in Musculoskeletal Medicine Aims and scope Submit manuscript

Abstract

Purpose of Review

Posterior spinal fusion (PSF) is the preferred treatment for adolescent idiopathic scoliosis (AIS) patients with surgical range curves. Selection of the proper upper and lower instrumented vertebrae (UIV and LIV) is essential in curve correction and achieving a successful outcome, while preventing short and long-term complications.

Recent Findings

The literature lacks high-level evidence, especially on outcomes of modern surgical techniques. However, evidence seems to show that a great majority of AIS patients have excellent clinical and functional long-term outcomes after PSF.

Summary

We have reviewed the evidence and provided our level selection recommendations, which should be weighed against the body of evidence on the topic when selecting fusion levels in AIS.

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
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

  1. Lander ST, Thirukumaran C, Saleh A, et al. Long-term health-related quality of life after harrington instrumentation and fusion for adolescent idiopathic scoliosis: a minimum 40-year follow-up. J Bone Joint Surg. 2022;104(11):995–1003. Long-term outcomes post-AIS fusion show that patients with a fusion down to L3 have better functional outcomes and fewer re-operations than L4.

    Article  PubMed  Google Scholar 

  2. Lenke LG, Edwards CC, Bridwell KH. The lenke classification of adolescent idiopathic scoliosis: how it organizes curve patterns as a template to perform selective fusions of the spine. Spine (Phila Pa 1976). 2003;28(20):199–207.

    Article  Google Scholar 

  3. Garg B, Mehta N, Bansal T, Malhotra R. Eos® imaging: concept and current applications in spinal disorders. J Clin Orthopaed Trauma. 2020;11(5):786–93.

    Article  Google Scholar 

  4. Jackson TJ, Miller D, Nelson S, Cahill PJ, Flynn JM. Two for one: a change in hand positioning during low-dose spinal stereoradiography allows for concurrent, reliable sanders skeletal maturity staging. Spine deformity. 2018;6(4):391–6. EOS imaging can provide scoliosis and hand radiographs at the same time with extremely low radiation.

    Article  PubMed  Google Scholar 

  5. Joshi T, Berman DC, Baghdadi S, et al. Pre-operative prone radiographs can reliably determine spinal curve flexibility in adolescent idiopathic scoliosis (ais). Spine deformity. 2022;10(5):1063–70.

    Article  PubMed  Google Scholar 

  6. Liu RW, Teng AL, Armstrong DG, Poe-Kochert C, Son-Hing JP, Thompson GH. Comparison of supine bending, push-prone, and traction under general anesthesia radiographs in predicting curve flexibility and postoperative correction in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2010;35(4):416–22.

    Article  PubMed  Google Scholar 

  7. Potter BK, Rosner MK, Lehman RA Jr, Polly DW Jr, Schroeder TM, Kuklo TR. Reliability of end, neutral, and stable vertebrae identification in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2005;30(14):1658–63.

    Article  PubMed  Google Scholar 

  8. Lenke LG, Betz RR, Harms J, et al. Adolescent idiopathic scoliosis : a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am. 2001;83(8):1169–81.

    Article  PubMed  CAS  Google Scholar 

  9. Pasha S, Baldwin K. Surgical outcome differences between the 3d subtypes of right thoracic adolescent idiopathic scoliosis. Eur Spine J. 2019;28(12):3076–84.

    Article  PubMed  Google Scholar 

  10. Demura S, Yaszay B, Bastrom TP, Carreau J, Newton PO, Harms Study G. Is decompensation preoperatively a risk in lenke 1c curves? Spine (Phila Pa 1976). 2013;38(11).

  11. Fischer CR, Kim Y. Selective fusion for adolescent idiopathic scoliosis: a review of current operative strategy. Eur Spine J. 2011;20(7):1048–57.

    Article  PubMed  PubMed Central  Google Scholar 

  12. Gomez JA, Matsumoto H, Colacchio ND, et al. Risk factors for coronal decompensation after posterior spinal instrumentation and fusion in adolescent idiopathic scoliosis. Spine Deform. 2014;2(5):380–5.

    Article  PubMed  Google Scholar 

  13. Baghdadi S, Cahill P, Anari J, et al. Evidence behind upper instrumented vertebra selection in adolescent idiopathic scoliosis: a systematic and critical analysis review. JBJS reviews. 2021:9(9):e20. Systematic review of the literature showing that we do not have high levels of evidence on almost any of the level selection decisions.

  14. Bjerke BT, Cheung ZB, Shifflett GD, Iyer S, Derman PB, Cunningham ME. Do current recommendations for upper instrumented vertebra predict shoulder imbalance? An attempted validation of level selection for adolescent idiopathic scoliosis. HSS J. 2015;11(3):216–22.

    Article  PubMed  PubMed Central  Google Scholar 

  15. Brooks JT, Bastrom TP, Bartley CE, et al. In search of the ever-elusive postoperative shoulder balance: is the t2 uiv the key? Spine Deform. 2018;6(6):707–11.

    Article  PubMed  Google Scholar 

  16. Gotfryd AO, Caffaro MFS, Meves R, Avanzi O. Predictors for postoperative shoulder balance in lenke 1 adolescent idiopathic scoliosis: a prospective cohort study. Spine Deform. 2017;5(1):66–71.

    Article  PubMed  Google Scholar 

  17. Tang X, Luo X, Liu C, et al. The spontaneous development of cosmetic shoulder balance and shorter segment fusion in adolescent idiopathic scoliosis with lenke i curve: a consecutive study followed up for 2 to 5 years. Spine (Phila Pa 1976). 2016;41(12):1028–35.

    Article  PubMed  Google Scholar 

  18. Ono T, Bastrom TP, Newton PO. Defining 2 components of shoulder imbalance: clavicle tilt and trapezial prominence. Spine (Phila Pa 1976). 2012;37(24):E1511–6.

    Article  PubMed  Google Scholar 

  19. Ahmed SI, Bastrom TP, Yaszay B, Newton PO. 5-year reoperation risk and causes for revision after idiopathic scoliosis surgery. Spine (Phila Pa 1976). 2017;42(13):999–1005.

    Article  PubMed  Google Scholar 

  20. Chan CYW, Chiu CK, Kwan MK. Assessing the flexibility of the proximal thoracic segments above the “potential upper instrumented vertebra” using the cervical supine side bending radiographs in lenke 1 and 2 curves for adolescent idiopathic scoliosis patients. Spine (Phila Pa 1976). 2016;41(16):E973–80.

    Article  PubMed  Google Scholar 

  21. Sielatycki JA, Cerpa M, Beauchamp EC, et al. The amount of relative curve correction is more important than upper instrumented vertebra selection for ensuring postoperative shoulder balance in lenke type 1 and type 2 adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2019:44(17):E1031-E7. The pre-operative shoulder level is less important than the relative correction between the MT and PT curves. Since PT curves are often rigid, one may undercorrect the MT curve to prevent shoulder imbalance.

  22. Vigneswaran HT, Grabel ZJ, Eberson CP, Palumbo MA, Daniels AH. Surgical treatment of adolescent idiopathic scoliosis in the united states from 1997 to 2012: an analysis of 20, 346 patients. J Neurosurg Pediatr. 2015;16(3):322–8.

    Article  PubMed  Google Scholar 

  23. Ilharreborde B, Ferrero E, Angelliaume A, et al. Selective versus hyperselective posterior fusions in lenke 5 adolescent idiopathic scoliosis: comparison of radiological and clinical outcomes. Eur Spine J. 2017;26(6):1739–47.

    Article  PubMed  CAS  Google Scholar 

  24. Kwan MK, Chiu CK, Chan TS, Gani SMA, Tan SH, Chan CYW. Flexibility assessment of the unfused thoracic segments above the “potential upper instrumented vertebrae” using the supine side bending radiographs in lenke 5 and 6 curves for adolescent idiopathic scoliosis patients. Spine J. 2018;18(1):53–62.

    Article  PubMed  Google Scholar 

  25. Beauchamp EC, Lenke LG, Cerpa M, Newton PO, Kelly MP, Blanke KM. Selecting the “touched vertebra” as the lowest instrumented vertebra in patients with lenke type-1 and 2 curves: radiographic results after a minimum 5-year follow-up. J Bone Joint Surg Am. 2020:102(22):1966–73. Selecting the “touched vertebra” as the LIV provided excellent ouctomes in Lenke 1 and 2 curvein the study of 299 patients.

  26. Cao K, Watanabe K, Kawakami N, et al. Selection of lower instrumented vertebra in treating lenke type 2a adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2014;39(4):E253–61.

    Article  PubMed  Google Scholar 

  27. Qin X, Sun W, Xu L, Liu Z, Qiu Y, Zhu Z. Selecting the last “substantially” touching vertebra as lowest instrumented vertebra in lenke type 1a curve: radiographic outcomes with a minimum of 2-year follow-up. Spine (Phila Pa 1976). 2016;41(12):E742–50.

    Article  PubMed  Google Scholar 

  28. Wang P-Y, Chen C-W, Lee Y-F, et al. Distal junctional kyphosis after posterior spinal fusion in lenke 1 and 2 adolescent idiopathic scoliosis-exploring detailed features of the sagittal stable vertebra concept. Global Spine Journal. 2021;21925682211019692.

  29. Sanchez-Raya J, Bago J, Pellise F, Cuxart A, Villanueva C. Does the lower instrumented vertebra have an effect on lumbar mobility, subjective perception of trunk flexibility, and quality of life in patients with idiopathic scoliosis treated by spinal fusion? Clinical Spine Surgery. 2012;25(8).

  30. Engsberg JR, Lenke LG, Reitenbach AK, Hollander KW, Bridwell KH, Blanke K. Prospective evaluation of trunk range of motion in adolescents with idiopathic scoliosis undergoing spinal fusion surgery. Spine (Phila Pa 1976). 2002;27(12).

  31. Cho RH, Yaszay B, Bartley CE, Bastrom TP, Newton PO. Which lenke 1a curves are at the greatest risk for adding-on... And why? Spine (Phila Pa 1976). 2012;37(16):1384–90.

    Article  PubMed  Google Scholar 

  32. Murphy JS, Upasani VV, Yaszay B, et al. Predictors of distal adding-on in thoracic major curves with ar lumbar modifiers. Spine (Phila Pa 1976). 2017;42(4):E211–8.

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Keith Baldwin.

Ethics declarations

Conflict of Interest

The authors have no competing interests to declare that are relevant to the content of this article.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.

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

Baghdadi, S., Baldwin, K. Selection of Fusion Levels in Adolescent Idiopathic Scoliosis. Curr Rev Musculoskelet Med 17, 23–36 (2024). https://doi.org/10.1007/s12178-023-09876-6

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12178-023-09876-6

Keywords

Navigation