title: Effects of spine loading in a patient with post-decompression lumbar disc herniation: observations using an open weight-bearing MRI.
abstract: Our objective was to use an open weight-bearing MRI to identify the effects of different loading conditions on the inter-vertebral anatomy of the lumbar spine in a post-discectomy recurrent lumbar disc herniation patient.
  
  
  
  A 43-year-old male with a left-sided L5-S1 post-decompression re-herniation underwent MR imaging in three spine-loading conditions: (1) supine, (2) weight-bearing on standing (WB), and (3) WB with 10 % of body mass axial loading (WB + AL) (5 % through each shoulder). A segmentation-based proprietary software was used to calculate and compare linear dimensions, angles and cross sections across the lumbar spine.
  
  
  
  The L5 vertebrae showed a 4.6 mm posterior shift at L5-S1 in the supine position that changed to an anterior translation >2.0 mm on WB. The spinal canal sagittal thickness at L5-S1 reduced from supine to WB and WB + AL (13.4, 10.6, 9.5 mm) with corresponding increases of 2.4 and 3.5 mm in the L5-S1 disc protrusion with WB and WB + AL, respectively. Change from supine to WB and WB + AL altered the L5-S1 disc heights (10.2, 8.6, 7.0 mm), left L5-S1 foramen heights (12.9, 11.8, 10.9 mm), L5-S1 segmental angles (10.3°, 2.8°, 4.3°), sacral angles (38.5°, 38.3°, 40.3°), L1-L3-L5 angles (161.4°, 157.1°, 155.1°), and the dural sac cross sectional areas (149, 130, 131 mm2). Notably, the adjacent L4-L5 segment demonstrated a retro-listhesis >2.3 mm on WB.
  
  
  
  We observed that with weight-bearing, measurements indicative of spinal canal narrowing could be detected. These findings suggest that further research is warranted to determine the potential utility of weight-bearing MRI in clinical decision-making.
authors.affiliation: Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, USA. nm620511@ohio.edu.|Department of Biomedical Sciences, Ohio University, Athens, OH, USA. nm620511@ohio.edu.
authors.forename: Niladri Kumar
authors.initials: NK
authors.lastname: Mahato
authors.affiliation: Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, USA.|Division of Orthopedic Surgery, OrthoNeuro, New Albany, OH, USA.
authors.forename: Daryl
authors.initials: D
authors.lastname: Sybert
authors.affiliation: Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, USA.|Department of Family Medicine, Ohio University, Athens, OH, USA.|Clinical and Translational Research Unit, Ohio University, Athens, OH, USA.|Department of Geriatric Medicine, Ohio University, Athens, OH, USA.
authors.forename: Tim
authors.initials: T
authors.lastname: Law
authors.affiliation: Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, USA.|Department of Biomedical Sciences, Ohio University, Athens, OH, USA.|Department of Geriatric Medicine, Ohio University, Athens, OH, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Clark
mesh_terms: D000328:Adult; D019299:Decompression, Surgical; D017586:Diskectomy; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000503:physiopathology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D013115:Spinal Canal / Q000503:physiopathology; D016474:Weight-Bearing / Q000502:physiology*
keywords: Back pain; Dural sac; Lateral stenosis; Positional MRI; Segmentation; Spine motion; Weight-bearing MRI