Maximal Axial Vertebral Rotation in Adolescent Idiopathic Scoliosis: Is the Apical Vertebra the Most Rotated?

Abstract

Study Design: Retrospective cross-sectional study. Objectives: It is generally believed that the apical vertebra has the largest axial rotation in adolescent idiopathic scoliosis. We investigated the relationship between apical axial vertebral rotation (apicalAVR) and maximal axial vertebral rotation (maxAVR) in both major and minor curves using biplanar stereo-imaging. Methods: EOS 2D/3D biplanar radiograph images were collected from 332 patients with adolescent idiopathic scoliosis (Cobb angle range 10°-122°, mean age 14.7 years). Based on the X-ray images, with the help of 3D full spine reconstructions Cobb angle, curvature level, apicalAVR and maxAVR were determined. These parameters were also determined for minor curves in Lenke 2, 3, 4, 6 type patients. Maximal thoracic rotation and maximal thoracolumbar/lumbar rotation were calculated. Statistical analysis was performed with descriptive statistics, Shapiro-Wilk test, and Wilcoxon signed-rank test. Results: The apical vertebrae were the most rotated vertebra in only 40.4% of the major curves, and 31.7% in minor curves. MaxAVR significantly exceeded apicalAVR values in the major curves ( P < .001) as well as in minor curves ( P < .001). The 2 parameters differed significantly in each severity group and Lenke type. Conclusions: The apical vertebrae were not the most rotated vertebra in more than half of cases investigated indicating that apicalAVR and maxAVR should be considered as 2 distinct parameters, of which maxAVR fully describes the axial dimension of scoliosis. Furthermore, the substitution of maxAVR for the apicalAVR should be especially avoided in double and triple curves, as the apical vertebra was even less commonly the most rotated in minor curves.

Reliability Nash and Moe’s Grades in Patients With Adolescent Idiopathic Scoliosis

“…Knowledge of the reliability and reproducibility of a measure makes it possible to determine whether the effect of an intervention is greater than the variability of the measure itself and, therefore, whether it is real. 14,17 Marawar et al, 13 in an experimental study using synthetic models of vertebrae, found low agreement of the Nash & Moe classification (38.2% -53.9%) compared to the Upasani method (76.74% -80.23%). Kuklo et al, 7 using digital measurements, found only fair interobserver reliability (r= 0.53-0.59).…”

“…Assessment of the axial plane of AIS, with rotation of the apical vertebra as its most important parameter, has attracted increasing interest in recent years. 1,2,[5][6][7]9,13 The degree of vertebral rotation can be useful for monitoring the progression of scoliosis and assessing treatment results. 5,[14][15][16] Accurate assessment of vertebral rotation allows prediction of curve progression, the degree of correction, and possible decompensation of the coronal balance of the spine in the postoperative period.…”

Automatic Vertebral Rotation Angle Measurement of 3D Vertebrae Based on an Improved Transformer Network

“…The EOS imaging system is a cutting-edge, low-radiation, and highly accurate method for assessing spinal curvature. Some studies [28][29][30][31] have used EOS images to create comprehensive 3D spine reconstructions, forming the basis for measuring vertebral rotation angles with specialized software. While EOS imaging has been used to reconstruct 3D vertebral models in certain studies, measuring vertebral rotation angles often involves time-consuming manual point marking.…”

Gerinckorrekciós műtétek háromdimenziós hatékonysági vizsgálata serdülőkori idiopathiás gerincferdülésben

“…I.-L. V. csigolyákra. Az axiális csigolyarotációk adatsorából meghatároztuk az apicalAVR és a maximális csigolyarotáció (maxAVR) értékeit [24].…”

“…Az elterjedtebb apicalAVR-alapú vizsgálattal 56,7%-os derotációs hatékonyságot értünk el, amely érdemben megegyezik a szakirodalmi adatokkal [27]. A scoliosis axiális dimenzióját teljeskörűbben leíró maxAVR szerinti módszerrel 55,2%-os derotációs sikerességet mértünk [24]. A két módszer százalékos végeredményében azért nem érzékelhető érdemi különbség, mert a maxAVR az apical-AVR-nél szignifikánsan magasabb volt a preoperatív és a posztoperatív esetekben is, kiegyenlítve a kettőből számított műtéti hatékonyság mértékét.…”