The Spinopelvic Geometry in Different Lenke Curve Types of Adolescent Idiopathic Scoliosis

Abstract

Overall, the variances of spinopelvic parameters in different AIS curve types do not seem statistically large enough for a potential clinical relevance. However, the sacrum is more verticalized in AIS curves with major curves located in the lumbar/thoracolumbar region. It remains to be investigated whether such a verticalized sacrum might be a compensatory mechanism to keep the whole spine balanced and if it reverses with correction of the scoliosis.

Three-dimensional pelvic incidence is much higher in (thoraco)lumbar scoliosis than in controls

“…However, the PI of AIS patients was only based on 2D radiographs, whereas the PI of our study was measured using low-dose CT data and a computerized method based on accurate image processing techniques [22]. Mac-Thiong et al [10] and Farshad et al [13] found that the scoliotic curve type was not associated with a specific pattern of sagittal pelvic morphology and balance. However, the results of the present study showed a higher PI in Lenke curve type 5 as compared to Lenke curve type 1.…”

“…In these studies, the patients with scoliosis had a moderate to severe thoracic curve (mean Cobb angles varied between 35° and 60°); however, Schlösser et al [15] included only mild curves (Cobb angle 20° or lower) and found similar results (PI for thoracic AIS patients: 47°, PI for (thoraco)lumbar AIS patients: 42° and PI for controls: 43°; without significant differences). It has been described that the PI in AIS is higher as compared to the non-scoliotic controls; however, others described no significant differences between AIS patients and non-scoliotic adolescents [1,10,13,19,21,27,28]. Slight PI differences among studies could be explained by the differences in age, since the PI increases with age, but also to the inaccuracy of the 2D method [16,29].…”

“…Most studies described a relation between the PI and the (thoraco)lumbar sagittal alignment, but not between the PI and the thoracic alignment [10,13,17,19,21,27,30]. This suggests that the PI influences the (thoraco) lumbar region of the spine, but the thoracic part is independent of the PI.…”

“…Several other authors described the spino-pelvic balance in normal children and adolescents during growth and in patients with different pathologies [1,[10][11][12][13][14][15][16][17][18][19][20][21]. Dickson et al [5] described that differences in the sagittal plane (reversal of the normal thoracic kyphosis) during growth could initiate a progressive idiopathic scoliosis.…”

“…Dickson et al [5] described that differences in the sagittal plane (reversal of the normal thoracic kyphosis) during growth could initiate a progressive idiopathic scoliosis. Moreover, previous authors suggested a link between the spino-pelvic morphology and spinal deformities in the sagittal plane [1,[10][11][12][13][14][15][16][17][18][19][20][21]. Most of the previous studies obtained two-dimensional (2D) referential values using standing lateral radiographs that could lead to a deviation from the true sagittal plane and to a certain degree of distortion of the image.…”