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Selection of the lowest instrumented vertebra in main thoracic adolescent idiopathic scoliosis: Is it safe to fuse shorter than the last touched vertebra?

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Abstract

Hypothesis

Fusing shorter than the last touched vertebra (LTV) is a safe approach in flexible main thoracic (MT) adolescent idiopathic scoliosis (AIS) curves.

Methods

This was a prospective study on consecutive AIS patients surgically treated with selective fusion of the MT curve. Fusion-level selection was based on the fulcrum-bending radiograph method. Patients were grouped based on the position of the lowest instrumented vertebra as proximal to the LTV (proxLTV, n = 43), at the LTV (atLTV, n = 45), and distal to the LTV (distLTV, n = 21).

Results

A total of 109 patients were included in the study. Preoperatively, the distLTV group had greater lumbar Cobb angle, lumbar apical translation, and less flexibility in the MT curve. At 2-year follow-up, the groups did not differ in MT curve correction, but the distLTV had larger lumbar Cobb angle, more apical translation, and worse coronal balance. Distal adding-on was observed in 11 patients (26%) in the proxLTV group, four patients (9%) in the atLTV group, and one patient (5%) in the distLTV group (p = 0.031). Adding-on was associated with younger patients and lower Risser grade at the time of surgery but not with any other radiographic parameter. No differences in SRS-22r scores were observed between the groups.

Conclusions

Proximal fusion carries the risk of adding-on, but leaving unfused segments in the lower spine increases the potential for compensatory mechanisms to improve spinal and truncal balance. In mature patients with a flexible MT curve, surgeons may consider fusion at or cranial to the LTV.

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References

  1. Fischer CR, Kim Y (2011) Selective fusion for adolescent idiopathic scoliosis: a review of current operative strategy. Eur Spine J 20:1048–1057

    Article  Google Scholar 

  2. Rose PS, Lenke LG (2007) Classification of operative adolescent idiopathic scoliosis: treatment guidelines. Orthop Clin North Am 38:521–529

    Article  Google Scholar 

  3. Lee MC, Õunpuu S, Solomito M et al (2013) Loss in spinal motion from inclusion of a single midlumbar level in posterior spinal fusion for adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 38:1405–1410

    Article  Google Scholar 

  4. Marks M, Newton PO, Petcharaporn M et al (2012) Postoperative segmental motion of the unfused spine distal to the fusion in 100 patients with adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 37:826–832

    Article  Google Scholar 

  5. Sanchez-Raya J, Bago J (2012) The effect of the lower instrumented vertebra (LIV) on pain and quality of life in patients surgically treated for an idiopathic scoliosis. Scoliosis 7:437–442

    Google Scholar 

  6. Larson AN, Polly DW, Ackerman SJ et al (2016) What would be the annual cost savings if fewer screws were used in adolescent idiopathic scoliosis treatment in the US? J Neurosurg Spine 24:116–123

    Article  Google Scholar 

  7. Erickson MA, Baulesh DM (2011) Lowest instrumented vertebra selection in AIS. J Pediatr Orthop 31:S69–S76

    Article  Google Scholar 

  8. Lenke L, Newton P, Lehman R et al (2017) Radiographic Results of Selecting the Touched Vertebra as the Lowest Instrumented Vertebra in Lenke Type 1 (Main Thoracic) & Type 2 (Double Thoracic) Curves at a Minimum 5-year Follow-up. Glob Spine J 7:2S–189S

    Article  Google Scholar 

  9. Cao K, Watanabe K, Kawakami N et al (2014) Selection of lower instrumented vertebra in treating Lenke type 2A adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 39:E253–E261

    Article  Google Scholar 

  10. Lee CS, Hwang CJ, Lee DH, Cho JH (2016) Five major controversial issues about fusion level selection in corrective surgery for adolescent idiopathic scoliosis: a narrative review. Spine J 17:1033–1044

    Article  Google Scholar 

  11. Cheung KMC, Natarajan D, Samartzis D et al (2010) Predictability of the fulcrum bending radiograph in scoliosis correction with alternate-level pedicle screw fixation. J Bone Jt Surg Am 92:169–176

    Article  Google Scholar 

  12. Luk KDK, Don AS, Chong CS et al (2008) Selection of fusion levels in adolescent idiopathic scoliosis using fulcrum bending prediction: a prospective study. Spine (Phila Pa 1976) 33:2192–2198

    Article  Google Scholar 

  13. Samartzis D, Leung Y, Shigematsu H et al (2015) Selection of fusion levels using the fulcrum bending radiograph for the management of adolescent idiopathic scoliosis patients with alternate level pedicle screw strategy: Clinical decision-making and outcomes. PLoS ONE 10:e0120302

    Article  Google Scholar 

  14. Nissen SO, Kamath VHD, Samartzis D et al (2018) Fulcrum flexibility of the main curve predicts postoperative shoulder imbalance in selective thoracic fusion of adolescent idiopathic scoliosis. Eur Spine J 27:2251–2261

    Article  Google Scholar 

  15. Shigematsu H, Cheung JPY, Bruzzone M et al (2017) Preventing fusion mass shift avoids postoperative distal curve adding-on in adolescent idiopathic scoliosis. Clin Orthop Relat Res 475:1448–1460

    Article  Google Scholar 

  16. Cao K, Watanabe K, Hosogane N et al (2014) Association of postoperative shoulder balance with adding-on in Lenke Type II adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 39:705–712

    Article  Google Scholar 

  17. Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174

    Article  CAS  Google Scholar 

  18. Aubin C-E, Labelle H, Ciolofan OC (2007) Variability of spinal instrumentation configurations in adolescent idiopathic scoliosis. Eur Spine J 16:57–64

    Article  Google Scholar 

  19. Robitaille M, Aubin CE, Labelle H (2007) Intra and interobserver variability of preoperative planning for surgical instrumentation in adolescent idiopathic scoliosis. Eur Spine J 16:1604–1614

    Article  CAS  Google Scholar 

  20. Newton PO, Faro FD, Lenke LG et al (2003) Factors involved in the decision to perform a selective versus nonselective fusion of Lenke 1B and 1C (King-Moe II) curves in adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 28:S217–S223

    Article  Google Scholar 

  21. DeFrancesco CJ, Pasha S, Miller DJ et al (2018) Agreement between manual and computerized designation of neutral vertebra in idiopathic scoliosis. Spine Deform 6:644–650

    Article  Google Scholar 

  22. Shigematsu H, Cheung JPY, Bruzzone M et al (2017) Preventing fusion mass shift avoids postoperative distal curve adding-on in adolescent idiopathic scoliosis. Clin Orthop Relat Res 1–13(475):1448–1460

    Article  Google Scholar 

  23. Cho RH, Yaszay B, Bartley CE et al (2012) Which Lenke 1A curves are at the greatest risk for adding-on.. and why? Spine (Phila Pa 1976) 37:1384–1390

    Article  Google Scholar 

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Authors and Affiliations

  1. Spine Unit, Department of Orthopedic Surgery, Copenhagen University Hospital, Rigshospitalet University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark

    Søren Ohrt-Nissen

  2. Department of Orthopedics and Traumatology, The University of Hong Kong, Queen Mary Hospital, 5/F Professorial Block, Pokfulam, Hong Kong, SAR, China

    Keith D. K. Luk & Jason Pui Yin Cheung

  3. Department of Orthopaedic Surgery, RUSH University Medical Center, Chicago, USA

    Dino Samartzis

Authors
  1. Søren Ohrt-Nissen
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  2. Keith D. K. Luk
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  3. Dino Samartzis
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  4. Jason Pui Yin Cheung
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Correspondence to Søren Ohrt-Nissen or Jason Pui Yin Cheung.

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The authors have no financial or competing interests related to this work.

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This study was approved by the Institutional Review Board at The University of Hong Kong.

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Ohrt-Nissen, S., Luk, K.D.K., Samartzis, D. et al. Selection of the lowest instrumented vertebra in main thoracic adolescent idiopathic scoliosis: Is it safe to fuse shorter than the last touched vertebra?. Eur Spine J 29, 2018–2024 (2020). https://doi.org/10.1007/s00586-020-06398-4

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  • DOI: https://doi.org/10.1007/s00586-020-06398-4

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