Standardized way for imaging of the sagittal spinal balance

Abstract

Nowadays, conventional or digitalized teleradiography remains the most commonly used tool for the study of the sagittal balance, sometimes with secondary digitalization. The irradiation given by this technique is important and the photographic results are often poor. Some radiographic tables allow the realization of digitalized spinal radiographs by simultaneous translation of X-ray tube and receptor. EOS system is a new, very low dose system which gives good quality images, permits a simultaneous acquisition of upright frontal and sagittal views, is able to cover in the same time the spine and the lower limbs and study the axial plane on 3D envelope reconstructions. In the future, this low dose system should take a great place in the study of the pelvispinal balance. On the lateral view, several pelvic (incidence, pelvic tilt, sacral slope) and spinal (lumbar lordosis, thoracic kyphosis, Th9 sagittal offset, C7 plumb line) parameters are drawn to define the pelvispinal balance. All are interdependent. Pelvic incidence is an individual anatomic characteristic that corresponds to the ''thickness'' of the pelvis and governs the spinal balance. Pelvis and spine, in a harmonious whole, can be compared to an accordion, more or less compressed or stretched.

Sagittal spinopelvic alignment in 654 degenerative spondylolisthesis

“…Standing biplanar full spine radiographs (36-in. films) were obtained using a standardized protocol already in place at the participating sites-patients were instructed to adopt a free standing position with horizontal gaze, and fists on clavicle to avoid superimposition of the arms with the spine [23,24]. All images included the base of the skull with the external meatus and the upper third of the femur.…”

Evaluation of Effect of Posterior Dynamic Stabilization IntraSPIN System on Sagittal Spinal Balance using EOS® X-Ray Imaging System

“…This system allows a very important reduction of the X-ray dose of an order of 80-90% versus conventional or digitalized radiographs [48]. An important dynamic range of 30000 gray levels and a pixel size of 250 m give good quality images [48] with a simultaneous visibility of thinnest regions as well as the thickest ones. Absence of parallax explains the lack of distortion of the anatomical structures.…”

“…These two devices scan the body of the patient, in a standing position, on a vertical distance varying from 5 to 180 cm [49]. This system allows a very important reduction of the X-ray dose of an order of 80-90% versus conventional or digitalized radiographs [48]. An important dynamic range of 30000 gray levels and a pixel size of 250 m give good quality images [48] with a simultaneous visibility of thinnest regions as well as the thickest ones.…”

“…Patients can assume many different compensatory postures, including a retroverted pelvis, extended hips, flexed knees, and dorsiflexion of the ankles to pull their head back over their pelvis [47]. Digitalized teleradiography in standing position allows a good evaluation of the sagittal balance and is the most commonly used system today, but the EOS X-rays brought a real progress for the study of the pelvi-spinal balance avoiding vertical parallax distortion with a very low dose of radiation [48]. This system is based on the use of a high sensitive detector developed by Dubousset et al [18,30].…”

Improvement in Scoliosis Top View: Evaluation of Vertebrae Localization in Scoliotic Spine-Spine Axial Presentation

“…However, no direct visualization of the axial plane has been provided. The three-dimensional deformity of scoliosis can be observed using computer tomography (CT) or a biplane low-dose X-ray imaging system (EOS) [6][7][8]. In 1983, De Smet et al proposed the "Top view" [9].…”