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Eur Spine J (2013) 22:24142420 DOI 10.1007/s00586-013-2852-z
ORIGINAL ARTICLE
Relationship between thoracic hypokyphosis, lumbar lordosis and sagittal pelvic parameters in adolescent idiopathic scoliosis
Jean-Luc Clment Anne Geoffray
Fatima Yagoubi Edouard Chau Federico Solla
Ioana Oborocianu Virginie Rampal
Received: 12 April 2012 / Revised: 21 April 2013 / Accepted: 1 June 2013 / Published online: 17 June 2013 Springer-Verlag Berlin Heidelberg 2013
AbstractPurpose Sagittal spine and pelvic alignment of adolescent idiopathic scoliosis (AIS) is poorly described in the literature. It generally reports the sagittal alignment with regard to the type of curve and never correlated to the thoracic kyphosis. The objective of this study is to investigate the relationship between thoracic kyphosis, lumbar lordosis and sagittal pelvic parameters in thoracic AIS. Methods Spinal and pelvic sagittal parameters were evaluated on lateral radiographs of 86 patients with thoracic AIS; patients were separated into hypokyphosis group (n = 42) and normokyphosis group (n = 44). Results were statistically analyzed. The lumbar lordosis was lower in the hypokyphosis group, due to the low proximal lordosis. The thoracic kyphosis was not correlated with any pelvic parameters but with the proximal lordosis. The pelvic incidence was correlated with sacral slope, pelvic tilt, lumbar lordosis and highly correlated with distal lumbar lordosis in the two groups. There was a signicant linear regression between thoracic kyphosis and proximal lordosis and between pelvic incidence and distal lordosis.
Conclusions We can consider that the proximal part of the lordosis depends on the thoracic kyphosis and the distal part depends on the pelvic incidence. The hypokyphosis in AIS is independent of the pelvic parameters and could be described as a structural parameter, characteristic of the scoliotic deformity.
Keywords Adolescent idiopathic scoliosis Thoracic
hypokyphosis Lumbar lordosis Pelvic incidence
Sagittal pelvic Spinal parameters
Introduction
Recent publications have shown the importance of considering the sagittal spinal and pelvic alignments for the treatment of spinal pathologies [1].
Duval-Beaupre [2] described the relationship between the pelvic anatomy and lumbar lordosis. They introduced the pelvic incidence (PI) angle, which is an anatomical parameter characteristic of the pelvic shape of each individual, unaffected by the orientation of the pelvis.
Many authors [212] showed that there are correlations between the adjacent pelvic and spinal sagittal parameters: PI and sacral slope (SS), PI and pelvic...