Three-dimensional ultrasonography could be a potential non-ionizing tool to evaluate vertebral rotation of subjects with adolescent idiopathic scoliosis

Tin Yan Lee; De Yang; Kelly Ka-Lee Lai; Rene M Castelein; Tom P C Schlosser; Winnie Chu; Tsz-Ping Lam; Yong-Ping Zheng

doi:10.1002/jsp2.1259

Three-dimensional ultrasonography could be a potential non-ionizing tool to evaluate vertebral rotation of subjects with adolescent idiopathic scoliosis

JOR Spine. 2023 May 8;6(3):e1259. doi: 10.1002/jsp2.1259. eCollection 2023 Sep.

Authors

Tin Yan Lee^{1

2}, De Yang¹, Kelly Ka-Lee Lai¹, Rene M Castelein³, Tom P C Schlosser³, Winnie Chu⁴, Tsz-Ping Lam⁵, Yong-Ping Zheng^{1

2}

Affiliations

¹ Department of Biomedical Engineering The Hong Kong Polytechnic University Hong Kong Hong Kong.
² Research Institute for Smart Ageing The Hong Kong Polytechnic University Hong Kong Hong Kong.
³ Department of Orthopaedic Surgery University Medical Center Utrecht Utrecht The Netherlands.
⁴ Department of Imaging and Interventional Radiology The Chinese University of Hong Kong Hong Kong SAR China.
⁵ SH Ho Scoliosis Research Lab, Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong Hong Kong Hong Kong.

Abstract

Background: Three-dimensional (3D) ultrasonography is nonionizing and has been demonstrated to be a reliable tool for scoliosis assessment, including coronal and sagittal curvatures. It shows a great potential for axial vertebral rotation (AVR) evaluation, yet its validity and reliability need to be further demonstrated.

Materials and methods: Twenty patients with adolescent idiopathic scoliosis (AIS) (coronal Cobb: 26.6 ± 9.1°) received 3D ultrasound scan for twice, 10 were scanned by the same operator, and the other 10 by different operators. EOS Bi-planar x-rays and 3D scan were conducted on another 29 patients on the same day. Two experienced 3D ultrasonographic researchers, with different experiences on AVR measurement, evaluated the 3D ultrasonographic AVR of the 29 patients (55 curves; coronal Cobb angle: 26.9 ± 11.3°). The gold standard AVR was determined from the 3D reconstruction of coronal and sagittal EOS radiographs. Intra-class correlation coefficients (ICCs), mean absolute difference (MAD), standard error measurements (SEM), and Bland-Altman's bias were reported to evaluate the intra-operator and inter-operator/rater reliabilities of 3D ultrasonography. The reliability of 3D ultrasonographic AVR measurements was further validated using inter-method with that of EOS.

Results: ICCs for intra-operator and inter-operator/rater reliability assessment were all greater than 0.95. MAD, SEM, and bias for the 3D ultrasonographic AVRs were no more than 2.2°, 2.0°, and 0.5°, respectively. AVRs between both modalities were strongly correlated (R ² = 0.901) and not significantly different (p = 0.205). Bland-Altman plot also shows that the bias was less than 1°, with no proportional bias between the difference and mean of expected and radiographic Cobb angles.

Conclusion: This study demonstrates that 3D ultrasonography is valid and reliable to evaluate AVR in AIS patients. 3D ultrasonography can be a potential tool for screening and following up subjects with AIS and evaluating the effectiveness of nonsurgical treatments.

Keywords: adolescent idiopathic scoliosis; laminae; nonionizing axial; three‐dimensional ultrasonography; vertebral rotation.