Objective: The selection of the lowest instrumented vertebra (LIV) is crucial in the surgical treatment of adolescent idiopathic scoliosis (AIS), particularly for thoracolumbar/lumbar curves. While traditional LIV selection strategies primarily rely on weight-bearing radiographs, the utility of supine imaging remains unclear. This study aimed to evaluate the feasibility of using the last touched vertebra identified in the supine position (LTV-supine) as the LIV for Lenke-5 AIS.
Methods: We conducted a retrospective review of Lenke-5 AIS patients who underwent posterior spinal fusion at Peking Union Medical College Hospital from 2010 to 2017, with a minimum 5-year follow-up. All patients underwent distal fusion to the LTV-supine. Radiographic parameters, including coronal and sagittal alignments and LIV-related measurements (LIV tilt, translation, rotation, and the subjacent disc angle), as well as the Scoliosis Research Society-22 (SRS-22) scores were compared across preoperative, postoperative, and final follow-up time points using the paired t-tests. Based on the positional relationship between the LTV-supine (the selected LIV) and the LTV-upright, patients were categorized into two groups: the short-fusion group (LIV at the first vertebra proximal to the LTV-upright) and the non-short-fusion group (LIV at LTV-upright). Radiographic parameters, SRS-22 scores, and the incidence of radiographic complications were compared between groups using independent t-test.
Results: Forty-five consecutive patients were included. Radiographic outcomes demonstrated significant improvements: the thoracolumbar/lumbar curve Cobb angle was corrected from 49.2° ± 10.8° preoperatively to 8.3° ± 5.6° at final follow-up (correction rate: 83.4% ± 10.9%; p < 0.05), and the coronal balance decreased from 20.3 ± 10.0 mm to 11.2 ± 6.9 mm (p < 0.05). All LIV-related parameters showed significant improvement at the final follow-up compared to preoperative values (p < 0.05). SRS-22 scores showed notable enhancements in self-image/appearance and mental health domains at final follow-up (p < 0.05). Fusion to LTV-supine saved 0.3 ± 0.5 distal vertebrae compared to the LTV-upright strategy (p < 0.05), resulting in shorter fusions in one-third of the patients (15/45). No significant differences were observed between the short-fusion (n = 15) and non-short-fusion (n = 30) groups in the final follow-up Cobb angle, correction rate, SRS-22 domain scores, nor in the incidence of adverse radiographic outcomes, such as sloped LIV, subjacent disc wedging, or coronal imbalance.
Conclusions: Supine imaging serves as a valuable adjunct for LIV selection in AIS. For Lenke-5 AIS, adopting the LTV-supine can yield comparable radiographic outcomes while potentially sparing additional distal segments in a subset of patients compared to the conventional upright radiograph-based approach.
| [1] |
T. Banno, Y. Yamato, H. Oba, et al., “Should L3 Be Selected as the Lowest Instrumented Vertebra in Patients With Lenke Type 5C Adolescent Idiopathic Scoliosis Whose Lowest End Vertebra Is L4?,” Journal of Neurosurgery. Spine 35 (2021): 1–10.
|
| [2] |
D. G. Chang, S. I. Suk, K. S. Song, et al., “How to Avoid Distal Adding-On Phenomenon for Rigid Curves in Major Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis? Identifying the Incidence of Distal Adding-On by Selection of Lowest Instrumented Vertebra,” World Neurosurgery 132 (2019): e472–e478.
|
| [3] |
B. J. Bartie, J. E. Lonstein, and R. B. Winter, “Long-Term Follow-Up of Adolescent Idiopathic Scoliosis Patients Who Had Harrington Instrumentation and Fusion to the Lower Lumbar Vertebrae: Is Low Back Pain a Problem?,” Spine 34 (2009): E873–E878.
|
| [4] |
A. Nohara, N. Kawakami, K. Seki, et al., “The Effects of Spinal Fusion on Lumbar Disc Degeneration in Patients With Adolescent Idiopathic Scoliosis: A Minimum 10-Year Follow-Up,” Spine Deformity 3 (2015): 462–468.
|
| [5] |
P. R. Harrington, “Treatment of Scoliosis. Correction and Internal Fixation by Spine Instrumentation,” Journal of Bone and Joint Surgery. American Volume 44-A (1962): 591–610.
|
| [6] |
L. A. Goldstein, “The Surgical Management of Scoliosis,” Clinical Orthopaedics and Related Research 35 (1964): 95–115.
|
| [7] |
L. A. Goldstein, “The Surgical Management of Scoliosis,” Clinical Orthopaedics and Related Research 77 (1971): 32–56.
|
| [8] |
S. I. Suk, S. M. Lee, E. R. Chung, J. H. Kim, W. J. Kim, and H. M. Sohn, “Determination of Distal Fusion Level With Segmental Pedicle Screw Fixation in Single Thoracic Idiopathic Scoliosis,” Spine 28 (2003): 484–491.
|
| [9] |
E. C. Beauchamp, L. G. Lenke, M. Cerpa, P. O. Newton, M. P. Kelly, and K. M. Blanke, “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,” Journal of Bone and Joint Surgery. American Volume 102 (2020): 1966–1973.
|
| [10] |
X. Qin, W. Sun, L. Xu, Z. Liu, Y. Qiu, and Z. Zhu, “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 41 (2016): E742–E750.
|
| [11] |
J. Bai, K. Chen, Q. Wei, et al., “Selecting the LSTV as the Lower Instrumented Vertebra in the Treatment of Lenke Types 1A and 2A Adolescent Idiopathic Scoliosis: A Minimal 3-Year Follow-Up,” Spine 43 (2018): E390–E398.
|
| [12] |
X. Qin, Y. Qiu, Z. He, R. Yin, Z. Liu, and Z. Zhu, “Can we Stop Distally at LSTV-1 for Adolescent Idiopathic Scoliosis With Lenke 1A/2A Curves?,” Spine 47 (2022): 624–631.
|
| [13] |
S. Ohrt-Nissen, K. D. K. Luk, D. Samartzis, and J. P. Y. Cheung, “Selection of the Lowest Instrumented Vertebra in Main Thoracic Adolescent Idiopathic Scoliosis: Is It Safe to Fuse Shorter Than the Last Touched Vertebra?,” European Spine Journal 29 (2020): 2018–2024.
|
| [14] |
C. Zetterberg, T. Hansson, J. Lindstrom, L. Irstam, and G. B. Andersson, “Postural and Time-Dependent Effects on Body Height and Scoliosis Angle in Adolescent Idiopathic Scoliosis,” Acta Orthopaedica Scandinavica 54 (1983): 836–840.
|
| [15] |
G. Cheh, L. G. Lenke, R. A. Lehman, Y. J. Kim, R. Nunley, and K. H. Bridwell, “The Reliability of Preoperative Supine Radiographs to Predict the Amount of Curve Flexibility in Adolescent Idiopathic Scoliosis,” Spine 32 (2007): 2668–2672.
|
| [16] |
M. Prost, J. Windolf, and M. R. Konieczny, “May Bending Radiographs Be Replaced by Recumbent CT Scans in Patients With Adolescent Idiopathic Scoliosis?,” European Spine Journal 30 (2021): 3490–3497.
|
| [17] |
M. Prost, M. E. Rockner, R. Taday, J. Windolf, and M. R. Konieczny, “May Bending Radiographs Be Replaced by Magnetic Resonance Imaging in Patients With Adolescent Idiopathic Scoliosis?,” European Spine Journal 32 (2023): 1771–1776.
|
| [18] |
S. Ramchandran, A. Monsour, A. Mihas, K. George, T. Errico, and S. George, “Impact of Supine Radiographs to Assess Curve Flexibility in the Treatment of Adolescent Idiopathic Scoliosis,” Global Spine Journal 12 (2022): 1731–1735.
|
| [19] |
M. Zhang, W. Chen, S. Wang, Y. Du, J. Zhang, and F. Pu, “Correlation Between Supine Flexibility and Postoperative Correction in Adolescent Idiopathic Scoliosis,” BMC Musculoskeletal Disorders 24 (2023): 126.
|
| [20] |
D. H. Kim, S. J. Hyun, C. H. Lee, and K. J. Kim, “The Last Touched Vertebra on Supine Radiographs Can Be the Optimal Lower Instrumented Vertebra in Adolescent Idiopathic Scoliosis Patients,” Neurospine 19 (2022): 236–243.
|
| [21] |
T. Banno, Y. Yamato, H. Oba, et al., “Preoperative Thoracic Curve Magnitude and L4 End Vertebra Were Risk Factors for Subjacent Disc Wedging After Selective Thoracolumbar/Lumbar Fusion With L3 as the Lowest Instrumented Vertebra in Lenke Type 5 Curve Patients,” Spine 46 (2021): E878–E887.
|
| [22] |
Y. Wang, E. S. Hansen, K. Hoy, C. Wu, and C. E. Bunger, “Distal Adding-On Phenomenon in Lenke 1A Scoliosis: Risk Factor Identification and Treatment Strategy Comparison,” Spine 36 (2011): 1113–1122.
|
| [23] |
X. Shao, W. Sui, Y. Deng, J. Yang, J. Chen, and J. Yang, “How to Select the Lowest Instrumented Vertebra in Lenke 5/6 Adolescent Idiopathic Scoliosis Patients With Derotation Technique,” European Spine Journal 31 (2022): 996–1005.
|
| [24] |
Q. Zhuang, J. Zhang, S. Wang, Y. Yang, and G. Lin, “How to Select the Lowest Instrumented Vertebra in Lenke Type 5 Adolescent Idiopathic Scoliosis Patients?,” Spine Journal 21 (2021): 141–149.
|
| [25] |
C. J. Hwang, C. S. Lee, H. Kim, D. H. Lee, and J. H. Cho, “Spontaneous Correction of Coronal Imbalance After Selective Thoracolumbar-Lumbar Fusion in Patients With Lenke-5C Adolescent Idiopathic Scoliosis,” Spine Journal 18 (2018): 1822–1828.
|
| [26] |
L. Phillips, B. Yaszay, T. P. Bastrom, et al., “L3 Translation Predicts When L3 Is Not Distal Enough for an “Ideal” Result in Lenke 5 Curves,” European Spine Journal 28 (2019): 1349–1355.
|
| [27] |
Y. Wang, C. E. Bunger, Y. Zhang, et al., “Lowest Instrumented Vertebra Selection for Lenke 5C Scoliosis: A Minimum 2-Year Radiographical Follow-Up,” Spine 38 (2013): E894–E900.
|
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2025 The Author(s). Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.
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