13th International Conference on Conservative Management of Spinal Deformities and First Joint Meeting of the International Research Society on Spinal Deformities and the Society on Scoliosis Orthopaedic and Rehabilitation Treatment – SOSORT-IRSSD 2016 meeting

Abstract

Introduction Recently the EOS imaging system (EOS Imaging, Paris, France) has provided advancements in 3D spinal modeling. Advancements include low radiation as well as fast and accurate reconstructed measurements of spinal parameters. There is a paucity of studies analyzing the reproduci-bility of the EOS Imaging System and the sterEOS software in the production of 3D spinal models for children with adolescent idiopathic scoliosis (AIS). Objectives The purposes of the study were 1) to determine the intraclass correlation (ICC) for both the inter-observer and intra-observer in the measurements of Cobb angles in AP view as well as the Cobb angles in the lateral view; 2) to assess the ICC for inter-and intra-observer in the axial vertebral rotation (AVR) of the apex vertebra; 3) to compare differences of spinal parameters between two examiners and two trials; 4) to determine how long a 3D reconstruction of the spine takes. Methods Bilateral x-ray images of fifteen patients (age: 6-15 years old, 5 males, 10 females) were retrospectively selected. These EOS images were uploaded into the sterEOS computer program. Within the software, spinal and pelvic parameters were identified manually to construct a 3D model of the spine. The sterEOS software calculates the Cobb angles, angles of lordosis, angles of kyphosis, and the AVRs of the apex vertebra. The 3D modeling was performed independently by two examiners. Each examiner modeled each patient's spine in two spaced out trials. The ICC between inter-and intra-observers were calculated and compared statistically. Results and discussion Both the inter-and intra-observers showed excellent reproducibility for the Cobb angles in the proximal segment (ICC: 0.72-0.91), kyphosis (ICC: 0.85-0.92), and lordosis (ICC: 0.82-0.95). No significant differences were found between angle differences (0.35° to 2.4°). In contrast to the traditional radiography, the sterEOS provides a better high quality view within the sagittal plane. A moderate inter-observer ICC for the Cobb angle in the distal segment (ICC = 0.67) indicates the examiners have to carefully adjust the alignment and vertebrae in 3D rather than in 2D following the automatic computation from the EOS software. The inter-observer ICC for the AVR in the lumbar region (0.80) is higher than the thoracic or thoracolumbar region (0.65), but with high differences of AVR (4.0°-6.3°). The average time that two examiners spent per subject ranged from 34.6 to 37.4 minutes. Conclusion and significance EOS provides significantly reliable and accurate spinal modeling in the measurement of children with AIS. Exposure to less radiation as compared to other radiographic modality allows EOS to offer acceptable quality view of the spine in the sagittal and transversal plane. O2 Classification and agreement of sagittal balance and compensatory mechanics in younger and older adults with scoliosis