Investigation of geometric deformations of the lumbar disc during axial body rotations

Abstract

Background Quantitative data on in vivo vertebral disc deformations are critical for enhancing our understanding of spinal pathology and improving the design of surgical materials. This study investigated in vivo lumbar intervertebral disc deformations during axial rotations under different load-bearing conditions. Methods Twelve healthy subjects (7 males and 5 females) between the ages of 25 and 39 were recruited. Using a combination of a dual fluoroscopic imaging system (DFIS) and CT, the images of L3–5 segments scanned by CT were transformed into three-dimensional models, which matched the instantaneous images of the lumbar spine taken by a double fluorescent X-ray system during axial rotations to reproduce motions. Then, the kinematic data of the compression and shear deformations of the lumbar disc and the coupled bending of the vertebral body were obtained. Results Relative to the supine position, the average compression deformation caused by rotation is between + 10% and − 40%, and the shear deformation is between 17 and 50%. Under physiological weightbearing loads, different levels of lumbar discs exhibit similar deformation patterns, and the deformation patterns of left and right rotations are approximately symmetrical. The deformation patterns change significantly under a 10 kg load, with the exception of the L3–4 disc during the right rotation. Conclusion The deformation of the lumbar disc was direction-specific and level-specific during axial rotations and was affected by extra weight. These data can provide new insights into the biomechanics of the lumbar spine and optimize the parameters of artificial lumbar spine devices.

A study on the relative motion trajectory of lumbar pedicles under physiological loads in vivo

“…Recently, there have been reports on the in vivo kinematics of the lumbar spine, including the characteristics of intervertebral disc motion and deformation [14], the range of motion of the lumbar small joints [9], and the characteristics of inter spinous process motion [10]. These studies not only led to the study of in vivo kinematics of the lumbar spine but also set the framework for the method by which in vivo kinematics data of the lumbar spine can be obtained under physiological loads to ultimately provide reference data for explaining the occurrence, development, and changes in lumbar degenerative diseases, as well as guiding treatment (especially nonfusion treatment).…”

The effect of lifting load on the kinematic characteristics of lumbar spinous process in vivo

“…In our published studies [ 23 , 26 ], the coupling translation part of intervertebral disc compression deformation and facet scoliosis were affected by an additional 10 kg load, while research on spinous process structure had no significant effect on load movement. This finding suggests that in spinal movement, the vertebral body and intervertebral joints conduct and limit spinal movement and bear most of the load.…”

“…The kinematic characteristics of the lumbar spine have been the focus of research. Previous studies on the lumbar spine are mainly focused on the anterior structures of the spine, such as the vertebral body [ 17 , 19 ], intervertebral disc [ 26 ], and facet joint [ 11 , 23 ]. A few scholars have focused on the spinous process, which can increase the firmness and stability of the spine [ 3 , 10 ].…”

Correction: Investigation of geometric deformations of the lumbar disc during axial body rotations

“…Author details 1 Clinical Department of Orthopaedics, Tianjin Medical University, Tianjin, China. 2 Department of Spine Surgery, Tianjin Hospital, Jiefangnanlu 406, Hexi District, Tianjin, China.…”

“…Following the publication of the original article [ 1 ], the authors found the incorrectly direction of coupled lateral bending under 10 kg load during right rotation in Fig. 6 and herein make corrections of these errors.…”