title: Transverse plane of apical vertebra of structural thoracic curve: vertebra displacement versus vertebral deformation.
abstract: CT transversal scans of the trunk provided at the level of Th8 or Th9 (apical vertebra) of 23 patients with structural thoracic scoliosis were reviewed. The following parameters were studied: 1) alpha angle formed by the axis of vertebra and the axis of spinous process, 2) beta concave and beta convex angle between the spinous process and the left and right transverse process respectively, 3) gamma concave and gamma convex angle between the axis of vertebra and the left and right transverse process respectively, 4) rotation angle to the sagittal plane according to Aaro and Dahlborn, 5) Cobb angle. Values of measured parameters demonstrated a common pattern of intravertebral deformity: counter clockwise deviation of the spinous process (alpha angle 15,0 +/-8,5 degrees), beta concave (69,8 +/-8,5 degrees) significantly greater than beta convex (38,8 +/-8,5 degrees), gamma concave (54,3 +/-7,8 degrees) not different from gamma convex (56,0 +/-8,0 degrees). Strong linear positive correlation between alpha angle and Aaro-Dahlborn angle was observed (r=0,78, p<0,05). Changes in morphology of apical vertebra due to intravertebral bone remodelling followed the vertebral spatial displacement and there existed a linear correlation in between. The two processes develop in opposite directions.
authors.affiliation: Dept of Paediatric Orthopaedics, University of Medical Sciences, ul. 28 Czerwca 1956 roku nr 135, 61-545 Poznan, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kotwicki
authors.forename: Marek
authors.initials: M
authors.lastname: Napiontek
authors.forename: Andrzej
authors.initials: A
authors.lastname: Nowakowski
mesh_terms: D006801:Humans; D011044:Poland; D012600:Scoliosis / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000002:abnormalities* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed