Do the three-dimensional parameters of brace-wearing patients with AIS change when transitioning from standing to sitting position? A preliminary study on Lenke I

Abstract

Background Bracing is the most common conservative treatment for preventing the progression of adolescent idiopathic scoliosis (AIS) in patients with a curve of 25°–40°. X-ray examinations are traditionally performed in the standing position. However, school-age teenagers may take more time to sit. Thus far, little is known about three-dimensional (3D) correction in the sitting position. Hence, this study aimed to determine the effects of standing and sitting positions on 3D parameters during brace correction. Methods We evaluated a single-center cohort of patients receiving conservative treatment for thoracic curvature (32 patients with AIS with a Lenke I curve). The 3D parameters of their standing and sitting positions were analyzed using the EOS imaging system during their first visit and after bracing. Results At the patients’ first visit, sagittal plane parameters such as thoracic kyphosis (TK), lumbar lordosis (LL), and sacral slope decreased when transitioning from the standing position to the sitting position (standing 29° ± 6°, 42° ± 8°, and 42° ± 8° vs. sitting 22° ± 5°, 27° ± 6°, and 24° ± 4°; p < 0.001), whereas pelvic tilt (PT) increased and sagittal vertical axis shifted forward (standing 9° ± 6° and 1.6 ± 2.7 cm vs. sitting 24° ± 4° and 3.8 ± 2.3 cm; p < 0.001). After bracing, TK and LL decreased slightly (from 29° ± 6° and 42° ± 8° to 23° ± 3° and 38° ± 6°; p < 0.001), whereas the thoracolumbar junction (TLJ) value increased (from 3° ± 3° to 11° ± 3°; p < 0.001). When transitioning to the sitting position, similar characteristics were observed during the first visit, except for a subtle increase in the TLJ and PT values (standing 11° ± 3° and 9° ± 4° vs. sitting 14° ± 3° and 28° ± 4°; p < 0.001). Moreover, the coronal and axial parameters at different positions measured at the same time showed no significant change. Conclusions In brace-wearing patients with thoracic scoliosis, compensatory sagittal plane straightening may be observed with a slight increase in thoracolumbar kyphosis, particularly when transitioning from the standing position to the sitting position, due to posterior rotation of the pelvis. Our results highlight that sagittal alignment in AIS with brace treatment is not completely analyzed with only standing X-Ray. Trial registration The study protocol was registered with the Chinese Clinical Trial Registry (ChiCTR1800018310).

Correlational analysis of three-dimensional spinopelvic parameters with standing balance and gait characteristics in adolescent idiopathic scoliosis: A preliminary research on Lenke V

“…To reduce the potential risk of radiation, posteroanterior views of the upper body and pelvis were taken using the micro-dose method. Subjects were asked to stand in the center of the cabin, with the pelvis located at the isocenter of the platform, and place both fists next to the cheeks with the upper arm at a 40° angle to the body and head facing forward ahead ( Zhang et al, 2022 ). Simultaneously, a 0.5 m plantar pressure measurement mat (Zebris FDM, Germany) was placed under the patient’s foot to collect their static plantar center of pressure (CoP) information for 10 s ( Figure 2 ).…”

Patient and surgical predictors of 3D correction in posterior spinal fusion: a systematic review

“…In recent years, three-dimensional reconstruction of biplanar radiographs has emerged as a method that allows accurate measurement of axial rotation and adjustment for axial rotation for a more accurate evaluation of the spine in its true planes [52][53][54][55][56][57][58]. After manual localization of the T1-L5 vertebral bodies, 3D spinal parameters will be automatically calculated with normalization of patient rotation.…”