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

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.

Three-dimensional efficacy of correction surgeries in adolescent idiopathic scoliosis / Gerinckorrekciós mutétek háromdimenziós hatékonysági vizsgálata serdülokori idiopathiás gerincferdülésben.

Összefoglaló. Bevezetés: Nincs egységesen elfogadott álláspont, hogy a serdülokori idiopathiás gerincferdülés sebészi korrekcióját melyik életkorban optimális elvégezni. Világszerte 11 éves kortól akár (kezeletlen esetben) 50-60 éves korig végeznek fúziós mutétet a betegségben, 63-83%-os átlagos koronális síkú korrekciós hatékonysággal. Célkituzés: Célul tuztük ki, hogy felmérjük a gerinckorrekciós mutétek hatékonyságát három dimenzióban, illetve a páciens életkorának függvényében. Módszerek: A vizsgálatba 23, serdülokori idiopathiás gerincferdüléssel diagnosztizált beteget (12 fo 17 évnél fiatalabb, 11 fo 17 évnél idosebb) vontunk be. Minden betegnél csavaros derotációt és spondylodesist végeztünk, és a beavatkozás elott és után EOS 2D/3D felvételeket, majd sterEOS 3D rekonstrukciókat készítettünk. A következo paramétereket számítottuk: Cobb-fok, háti kyphosis, ágyéki lordosis, apicalis csigolyarotáció, maximális csigolyarotáció. A különbözo életkorú csoportok közötti különbséget kétmintás t-próbával, illetve Wilcoxon-féle próbával vizsgáltuk. Eredmények: A gerinckorrekciós mutétek során a koronális síkú eltérést 78,2%-ban (átlagosan 55,1 Cobb-fokról 12,0 Cobb-fokra), az apicalis csigolyarotációt 56,7%-ban (átlagosan 21,0 fokról 9,1 fokra) tudtuk korrigálni. A 17 éves életkor után operált páciensek esetén átlagosan 79,2%-os Cobb-fok-csökkenést értünk el, míg a fiatalabb betegcsoportban 77,0%-ban korrigáltuk a koronális fogörbületet (p = 0,614). Az idosebb betegcsoportban szignifikánsan kevésbé sikerült az apicalis csigolyarotáció korrekciója (átlagosan 38,1%; 21,8 fokról 12,4 fokra), mint a fiatalabb pácienseknél (átlagosan 68,5%; 20,2 fokról 6,2 fokra; p = 0,016). Következtetés: Összességében a nemzetközi publikációknak megfelelo korrekciót értünk el. A koronális síkban közel azonos korrekciós hatékonyság figyelheto meg a különbözo életkorú betegcsoportok között, a csigolyarotáció azonban 17 éves életkor elott hatékonyabban korrigálható. Orv Hetil. 2021; 162(39): 1573-1578. INTRODUCTION: There is no clear recommendation for the optimal age to perform corrective surgery in adolescent idiopathic scoliosis. Fusion surgery is performed from the age of 11 to 50-60 years, with an average coronal plane correction efficiency of 63-83%. OBJECTIVE: We aimed to evaluate the effectiveness of correction surgeries in three dimensions in adolescent idiopathic scoliosis. In addition, our objective was to examine the influence of the patient's age on the correction. METHODS: The study included 23 patients with adolescent idiopathic scoliosis (12 patients younger than 17 years, 11 patients older than 17 years). All patients underwent screw-derotation and spondylodesis and underwent EOS 2D/3D imaging before and after the operation, followed by sterEOS 3D reconstructions. The following parameters were calculated: Cobb degree, thoracic kyphosis, lumbar lordosis, apical vertebral rotation, maximal vertebral rotation. Differences between different age groups were examined by paired-sample t-test and Wilcoxon rank sum test. RESULTS: The mean efficiency of correction surgeries was 78.2% in the coronal plane (from an average of 55.1 Cobb degrees to 12.0 Cobb degrees) and 56.7% in the axial plane (from an average of 21.0 degrees to 9.1 degrees). We achieved an average 79.2% reduction of Cobb angle in patients operated after the age of 17 years, which was 77.0% in the younger group (p = 0.614). Apical vertebral rotation correction was significantly less successful in the elderly group (mean 38.1%; from 21.8 degrees to 12.4 degrees) than in patients operated before the age of 17 years (mean 68.5%; from 20.2 degrees to 6.2 degrees; p = 0.016). CONCLUSION: We achieved scoliosis correction in line with the international publications. Nearly the same correction efficiency was observed between different age groups of patients in the coronal plane. However, vertebral rotation can be derotated more effectively before the age of 17 years. Orv Hetil. 2021; 162(39): 1573-1578.

Analysis of Proximal Femoral Parameters in Adolescent Idiopathic Scoliosis.

BACKGROUND: Assessment of the proximal femoral parameters in adolescent idiopathic scoliosis using three-dimensional radiological image reconstructions may allow better characterization than conventional techniques. METHODS: EOS 3D reconstructions of spines and femurs of 320 scoliotic patients (10-18 years old) and 350 control children lacking spinal abnormality were performed and 6 proximal femoral parameters measured. RESULTS: Individuals with adolescent idiopathic scoliosis showed a small but statistically significant decrease in neck shaft angle (average difference=2.58°) and a higher (0.22°) femoral mechanical axis-femoral shaft angle. When the two sides were compared based on curve direction, greater changes in the neck shaft angle and femoral mechanical axis-femoral shaft angle were found on the side of the convexity. CONCLUSIONS: Patients with adolescent idiopathic scoliosis were found to have a small but significantly lower neck shaft angle and higher femoral mechanical axis-femoral shaft angle, which related to the curve direction. This is postulated to be due to mechanical compensation for altered balance and centre of gravity associated with a scoliosis deformity, although the observed difference likely has negligible clinical effect.

Sagittal plane assessment of spino-pelvic complex in a Central European population with adolescent idiopathic scoliosis: a case control study.

BACKGROUND: Scoliosis is a complex three-dimensional deformity. While the frontal profile is well understood, increasing attention has turned to balance in the sagittal plane. The present study evaluated changes in sagittal spino-pelvic parameters in a large Hungarian population with adolescent idiopathic scoliosis. METHODS: EOS 2D/3D images of 458 scoliotic and 69 control cases were analyzed. After performing 3D reconstructions, the sagittal parameters were assessed as a whole and by curve type using independent sample t test and linear regression analysis. RESULTS: Patients with scoliosis had significantly decreased thoracic kyphosis (p < 0.001) with values T1-T12, 34.1 ± 17.1o vs. 43.4 ± 12.7o in control; T4-T12, 27.1 ± 18.8o vs. 37.7 ± 15.1o in control; and T5-T12, 24.9 ± 15.8o vs. 32.9 ± 15.0o in control. Changes in thoracic kyphosis correlated with magnitude of the Cobb angle (p < 0.001). No significant change was found in lumbar lordosis and the pelvic parameters. After substratification according to the Lenke classification and individually evaluating subgroups, results were similar with a significant decrease in only the thoracic kyphosis. A strong correlation was seen between sacral slope, pelvic incidence, and lumbar lordosis, and between pelvic version and thoracic kyphosis in control and scoliotic groups, whereas pelvic incidence was also seen to be correlated with thoracic kyphosis in scoliosis patients. CONCLUSION: Adolescent idiopathic scoliosis patients showed a significant decrease in thoracic kyphosis, and the magnitude of the decrease was directly related to the Cobb angle. Changes in pelvic incidence were minimal but were also significantly correlated with thoracic changes. Changes were similar though not identical to those seen in other Caucasian studies and differed from those in other ethnicities. Scoliotic curves and their effect on pelvic balance must still be regarded as individual to each patient, necessitating individual assessment, although changes perhaps can be predicted by patient ethnicity.

The effect of coronal decompensation on the biomechanical parameters in lower limbs in adolescent idiopathic scoliosis.

STUDY HYPOTHESIS: We hypothesized that altered coronal balance in adolescent scoliosis leads to asymmetric stress on the lower limbs, with subsequent effects on bone maturation and later morphology. We aimed to assess the correlation between the biomechanical parameters of the lower limbs and coronal balance in idiopathic scoliosis. MATERIALS AND METHODS: In this study, EOS images of 280 patients and 56 controls were randomly selected from our clinics' database. The average age of AIS patients was 14.5years and average Cobb angle 33.48°. Three D reconstructions of the pelvis and lower limbs were performed and coronal balance assessed. Reliability of measurements was ensured by intra- and inter-observer agreement. During statistical analysis the Kolmogorov-Smirnov test, t-test and linear regression analysis were performed. A p value <0.05 was considered significant. RESULTS: Of the 15 examined lower limb parameters, a significant difference between sides was found in those with AIS for femur length, total length, collodiaphyseal angle, angle between the femoral mechanical and anatomical axis and tibial torsion. In addition, the tibial length and the mechanical tibiofemoral angle were significantly higher than those of the controls. The coronal balance was found to be the strongest predictive factor showing a significant correlation with all of the previous parameters, except tibial torsion. With patients grouped based on coronal balance (compensated, right and left decompensated) the paired t-test also supported these findings. CONCLUSION: The biomechanical parameters of the lower limbs are affected in cases of scoliosis with an altered coronal balance. It was thought that a shift in balance in the coronal plane accounted for the small but significant changes seen in our study, with the lower limb on the side of decompensation becoming shorter in comparison to its' counterpart, with a lower collodiaphyseal angle and increased varus at the knee joint. LEVEL OF EVIDENCE: III, case-control study.

[Assessment of sacroiliacal joint mobility in patients with low back pain]. / A keresztcsonti ízület mobilitásának vizsgálata derékpanaszos betegcsoportban.

INTRODUCTION: Sagittal alignment of the pelvis is typically characterized using three fundamental parameters. Among these, pelvic incidence is traditionally considered to be anatomically 'constant'. AIM: We aimed to analyze the pelvic parameters of low back pain patients with suspected sacroiliac joint laxity. METHOD: Pelvic parameters were assessed in standing and seated EOS 2D/3D radiographs of 48 cases of persistent low back pain, and compared to upper body position using cluster analysis and t-test. RESULTS: Median pelvic incidence did not differ statistically between standing and sitting (47.8°-47.7°). However, in individual analysis 7 cases (15%) exhibited a forward tilt in their upper body with an increased pelvic incidence, and 7 cases (15%) showed a backward upper body tilt. No change was found in 34 cases. CONCLUSION: Our results indicate the pelvis should not be regarded as a rigid unit, as in some cases significant appreciable sacroiliac joint laxity can occur. Orv Hetil. 2017; 158(52): 2079-2085.