Abstract
Background
Proximal junctional kyphosis (PJK) is a reported complication of distraction-based growth-friendly surgery for early-onset scoliosis (EOS). A potential consequence of PJK is revision surgery with superior extension of the upper instrument vertebrae (UIV). The purpose of this study was to determine the risk of radiographic and clinically significant PJK during growth-friendly surgery.
Methods
This is a retrospective review of children treated with distraction-based growth-friendly surgeries from two EOS registries with minimum two-year follow-up. PJK is defined as clinically significant in this study if surgery with superior extension of the UIV was performed.
Results
Of 419 total patients, there was a 20% risk of developing clinically significant PJK (24% rib vs. 15% spine-based anchors, p = .03). These patients had a mean preoperative age of 5.6 years (5.2-year rib vs. 6.0-year spine, p < .001), scoliosis of 73° (69° rib vs. 77° spine, p < .001), and kyphosis of 51° (47° rib vs. 56° spine, p < .01). Regression analysis demonstrated that these differences in age, scoliosis, and kyphosis between anchor type did not account for a significant proportion of the measured variance.
Conclusions
There was a 20% risk of developing clinically significant PJK, with a slightly higher risk for patients treated with rib-based proximal anchors (24%) than for those patients treated with spine-based proximal anchors (15%).
Level of Evidence
Level III.
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References
National Scoliosis Foundation. Information and resources. Available at: http://www.scoliosis.org/info.php.
Labelle H, Richard S, Kleuver M, et al. Screening for idiopathic adolescent scoliosis: an information statement by the Scoliosis Research Society International Task Force. Scoliosis 8:1–6.
Skaggs D, Guillaume T, El-Hawary R, et al. n.d. Early onset scoliosis consensus statement, SRS Growing Spine Committee, 2015. Spine Deform. 2015;3:107.
El-Hawary R, Samdani A, Wade J, et al. Rib-based distraction surgery maintains total spine growth. J Pediatr Orthop. 2016;36:841–6.
Hollenbeck S, Glattes R, Asher M, et al. The prevalence of increased proximal junctional flexion following posterior instrumentation and arthrodesis for adolescent idiopathic scoliosis. Spine. 2008;33:1675–81.
Kim YJ, Lenke LG, Bridwell KH, et al. Proximal junctional kyphosis in adolescent idiopathic scoliosis after 3 different types of posterior segmental spinal instrumentation and fusions: incidence and risk factor analysis of 410 cases. Spine. 2007;32:2731–8.
El-Hawary R, Sturm P, Cahill P, et al. What is the risk of developing proximal junctional kyphosis during growth friendly treatments for early-onset scoliosis? J Pediatr Orthop. 2017;37:86–91.
Khudairy A, Gauthier L, Matz J, et al. Reliability of proximal junctional kyphosis measurements for young children with scoliosis. Spine Deform. 2014;2:448–53.
Li Y, Meryl G, Karlin L. Proximal junctional kyphosis after vertical expandable prosthetic titanium rib insertion. Spine Deform 2013;1:425e33.
Skaggs D, Myung K, Lee C. Proximal junctional kyphosis in distraction-based growing rods. Paper presented at: Fifth International Congress on Early Onset Scoliosis and Growing Spine; November 18–19, 2011; Orlando, FL.
Barrett K, Andras L, Tolo V, et al. Measurement variability in the evaluation of the proximal junction in distraction-based growing rods patients. J Pediatr Orthop. 2015;35:624–7.
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Author disclosures: NJ (none), OK (none), JH (personal fees from Globus Medical, outside the submitted work; in addition, JH has a patent US 9060810 issued), MSY (none), AM (none), TF (none), MS (none), DS (grants from Pediatric Orthopaedic Society of North America & Scoliosis Research Society, paid to Columbia University, and Ellipse [Co-PI, Paid to GSF]; personal fees from ZimmerBiomet, Medtronic, Zipline Medical, Inc., Orthobullets, Grand Rounds [a healthcare navigation company], and Greensunmedical; other from Zipline Medical, Inc., Green Sun Medical, and Orthobullets; nonfinancial support from Growing Spine Study Group, Scoliosis Research Society, and Growing Spine Foundation; personal fees from ZimmerBiomet, Medtronic, Johnson & Johnson, and Medtronic & ZimmerBiomet; other from Wolters Kluwer Health–Lippincott Williams & Wilkins, Biomet Spine, and Orthobullets, Co–Editor in Chief, outside the submitted work), RE-H (personal fees from DePuy Synthes Spine and Medtronic Spine; grants from DePuy Synthes Spine and Medtronic Spine; personal fees from Apifix Ltd.; other from Children’s Spine Foundation and Pediatric Orthopedic Society of North America, outside the submitted work).
Ethics approval: Approval from the IWK Health Sciences Centre Research Ethics Board.
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Joukhadar, N., Kubat, O., Heflin, J. et al. Superior Extension of Upper Instrumented Vertebrae in Distraction-based Surgery: A Surrogate for Clinically Significant Proximal Junctional Kyphosis. Spine Deform 7, 371–375 (2019). https://doi.org/10.1016/j.jspd.2018.08.011
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DOI: https://doi.org/10.1016/j.jspd.2018.08.011