Calculation of Intervertebral Disc Pressure in the Thoracic and Lumbar Spine in Elderly Women with Kyphosis Using a Novel Musculoskeletal Model with Isolated Thoracic Vertebrae and Rib Cage

Abstract

Background: Degeneration of the intervertebral disc is one of the causes of kyphosis. Several biomechanical studies have investigated the mechanisms of development of spinal deformity using simulation models. Realistic musculoskeletal models are helpful for investigating the pathophysiology and changes in internal forces in patients with kyphosis. However, the association between intervertebral disc pressure and kyphosis has not been fully elucidated to date. Purpose: To calculate intervertebral disc pressure in elderly women with kyphosis using a novel and precise thoracolumbar three-dimensional musculoskeletal model. Materials and Method: Ten female patients with a mean age of 80.0 ± 6.5 years who visited our hospital for medical examination of osteoporosis were included. The subjects were divided into the normal and kyphosis groups depending on their sagittal vertical axis. Intervertebral disc pressures in the thoracic and lumbar spines of subjects were analyzed by inverse dynamics analysis using a novel three-dimensional musculoskeletal model, and were compared between the groups. Result: Significant differences in lumbar lordosis (LL) were observed between the two groups. Furthermore, the kyphosis group was older and shorter. In the kyphosis group, the upper thoracic vertebrae (T1 -T6) showed significantly higher intervertebral pressure than the normal group. Conclusion: Intervertebral disc pressure in the thoracic and lumbar spines of patients with spinal deformities was evaluated using a novel thoracolumbar three-dimensional musculoskeletal model. Us-How to cite this paper: Iida, J., Miyakoshi,

Relationship between Intervertebral Disc Compression Force and Sagittal Spinopelvic Lower Limb Alignment in Elderly Women in Standing Position with Patient-Specific Whole Body Musculoskeletal Model

“…The input for the entire spinal sagittal alignment was based on a previously reported method [ 29 ]. On lateral whole-spine radiographs, the center of the vertebral body was defined as the intersection of the diagonals of the quadrilateral formed by each vertebra ( Figure 3 ).…”

“…Although there have been studies on AMS with altered thoracolumbar and pelvic alignment, there are no studies on altered cervical spine alignment [ 29 , 30 , 31 ]. Therefore, this study aimed to investigate the relationship between sagittal alignment, including cervical to lumbar spine, pelvis, and lower extremity in the standing position, and disc compression force ( ) from the cervical to the lumbar spine analyzed by patient-specific adapted AMS that also considered cervical spine alignment in elderly women.…”

Association between global sagittal malalignment and increasing hip joint contact force, analyzed by a novel musculoskeletal modeling system

“…The input for the sagittal alignment of the spine was based on a previously reported method [ 31 ]. The center of the vertebral body was identified as the intersection of the diagonal lines of the quadrilateral formed by each vertebral body in the lateral whole-spine radiographs.…”