Role of Spinal Load in the Pathophysiology of Lumbar Spinal Stenosis

This study is to improve the understanding of the role of postural and ambulatory biomechanics for symptoms in patients with sLSS and to correlate patient-reported outcome measures (PROMs) with dynamic compensation (difference between static and dynamic sagittal spinal alignment) in patients with symptomatic lumbar spinal stenosis sLSS).

Lumbar spinal stenosis (LSS) is a common syndrome affecting the human spine characterized by age related degeneration of the lumbar discs, facet joints (FJs) and hypertrophy of the ligamentum flavum resulting in pain, limited function and compromised quality of life. Understanding the interrelationship between spinal load, kinematics and functional disability is one of the key factors in the prevention of this disease. This project assesses sagittal spinal balance and motion in patients with sLSS using an optoelectronic method based on infrared cameras and retroreflective markers and elicits paraspinal muscle fatigue using a modified version of the Biering-Sørensen test and compares sagittal spinal balance and motion before and after the fatigue exercise, which will allow to associate sLSS-specific motion patterns to paraspinal muscle fatigue. Additional data generated using magnetic resonance imaging (MRI) allows detecting associations between sLSS, muscle degeneration and fatty infiltration. Radiological images from the spine will be obtained in upright position using EOS®, a specialized low-dose x-ray unit. These images will allow the calculation of the anatomical global and local sagittal spinal balance, enabling a characterization of spinal kinematics in patients with sLSS and a validation of the workflow based on the optoelectronic method. Coded data obtained from EOS and motion analysis will allow optimizing existing biomechanical musculoskeletal models of the human spine. The results of this study will provide first mechanistic evidence of the role of clinical, radiological, functional and biomechanical factors in spine load. The combination of in vivo experiments with in silico experiments represents a unique opportunity of translating knowledge gained from systematic experiments considering biological measurements back to the patient. This study is to improve the understanding of the role of postural and ambulatory biomechanics for symptoms in patients with sLSS.