Estimation of in vivo inter-vertebral loading during motion using fluoroscopic and magnetic resonance image informed finite element models

Authors: Zanjani-Pour,, S., Meakin, J.R., Breen, A.X. and Breen, A.C.

http://eprints.bournemouth.ac.uk/29846/

http://www.sciencedirect.com/science/article/pii/S0021929017304980

Journal: Journal of biomechanics

Publisher: Elsevier BV

ISSN: 0021-9290

DOI: 10.1016/j.jbiomech.2017.09.025

Finite element (FE) models driven by medical image data can be used to estimate subject-specific spinal biomechanics. This study aimed to combine magnetic resonance (MR) imaging and quantitative fluoroscopy (QF) in subject-specific FE models of upright standing, flexion and extension. Supine MR images of the lumbar spine were acquired from healthy participants using a 0.5 T MR scanner. Nine 3D quasi-static linear FE models of L3 to L5 were created with an elastic nucleus and orthotropic annulus. QF data was acquired from the same participants who performed trunk flexion to 60o and trunk extension to 20o. The displacements and rotations of the vertebrae were calculated and applied to the FE model. Stresses were averaged across the nucleus region and transformed to the disc co-ordinate system (S1 = mediolateral, S2 = anteroposterior, S3 = axial). In upright standing S3 was predicted to be -0.7 ± 0.6 MPa (L3L4) and -0.6 ± 0.5 MPa (L4L5). S3 increased to -2.0 ± 1.3 MPa (L3L4) and -1.2 ± 0.6 MPa (L4L5) in full flexion and to -1.1 ± 0.8 MPa (L3L4) and -0.7 ± 0.5 MPa (L4L5) in full extension. S1 and S2 followed similar patterns; shear was small apart from S23. Disc stresses correlated to disc orientation and wedging. The results demonstrate that MR and QF data can be combined in a participant-specific FE model to investigate spinal biomechanics in vivo and that predicted stresses are within ranges reported in the literature.

This data was imported from PubMed:

Authors: Zanjani-Pour, S., Meakin, J.R. and Breen, A.

http://eprints.bournemouth.ac.uk/29846/

Journal: J Biomech

Volume: 70

Pages: 134-139

eISSN: 1873-2380

DOI: 10.1016/j.jbiomech.2017.09.025

Finite element (FE) models driven by medical image data can be used to estimate subject-specific spinal biomechanics. This study aimed to combine magnetic resonance (MR) imaging and quantitative fluoroscopy (QF) in subject-specific FE models of upright standing, flexion and extension. Supine MR images of the lumbar spine were acquired from healthy participants using a 0.5 T MR scanner. Nine 3D quasi-static linear FE models of L3 to L5 were created with an elastic nucleus and orthotropic annulus. QF data was acquired from the same participants who performed trunk flexion to 60° and trunk extension to 20°. The displacements and rotations of the vertebrae were calculated and applied to the FE model. Stresses were averaged across the nucleus region and transformed to the disc co-ordinate system (S1 = mediolateral, S2 = anteroposterior, S3 = axial). In upright standing S3 was predicted to be -0.7 ± 0.6 MPa (L3L4) and -0.6 ± 0.5 MPa (L4L5). S3 increased to -2.0 ± 1.3 MPa (L3L4) and -1.2 ± 0.6 MPa (L4L5) in full flexion and to -1.1 ± 0.8 MPa (L3L4) and -0.7 ± 0.5 MPa (L4L5) in full extension. S1 and S2 followed similar patterns; shear was small apart from S23. Disc stresses correlated to disc orientation and wedging. The results demonstrate that MR and QF data can be combined in a participant-specific FE model to investigate spinal biomechanics in vivo and that predicted stresses are within ranges reported in the literature.

This data was imported from Scopus:

Authors: Zanjani-Pour, S., Meakin, J.R. and Breen, A.

http://eprints.bournemouth.ac.uk/29846/

Journal: Journal of Biomechanics

Volume: 70

Pages: 134-139

eISSN: 1873-2380

ISSN: 0021-9290

DOI: 10.1016/j.jbiomech.2017.09.025

© 2017 Elsevier Ltd Finite element (FE) models driven by medical image data can be used to estimate subject-specific spinal biomechanics. This study aimed to combine magnetic resonance (MR) imaging and quantitative fluoroscopy (QF) in subject-specific FE models of upright standing, flexion and extension. Supine MR images of the lumbar spine were acquired from healthy participants using a 0.5 T MR scanner. Nine 3D quasi-static linear FE models of L3 to L5 were created with an elastic nucleus and orthotropic annulus. QF data was acquired from the same participants who performed trunk flexion to 60° and trunk extension to 20°. The displacements and rotations of the vertebrae were calculated and applied to the FE model. Stresses were averaged across the nucleus region and transformed to the disc co-ordinate system (S1 = mediolateral, S2 = anteroposterior, S3 = axial). In upright standing S3 was predicted to be −0.7 ± 0.6 MPa (L3L4) and −0.6 ± 0.5 MPa (L4L5). S3 increased to −2.0 ± 1.3 MPa (L3L4) and −1.2 ± 0.6 MPa (L4L5) in full flexion and to −1.1 ± 0.8 MPa (L3L4) and −0.7 ± 0.5 MPa (L4L5) in full extension. S1 and S2 followed similar patterns; shear was small apart from S23. Disc stresses correlated to disc orientation and wedging. The results demonstrate that MR and QF data can be combined in a participant-specific FE model to investigate spinal biomechanics in vivo and that predicted stresses are within ranges reported in the literature.

This data was imported from Web of Science (Lite):

Authors: Zanjani-Pour, S., Meakin, J.R. and Breen, A.

http://eprints.bournemouth.ac.uk/29846/

Journal: JOURNAL OF BIOMECHANICS

Volume: 70

Pages: 134-139

eISSN: 1873-2380

ISSN: 0021-9290

DOI: 10.1016/j.jbiomech.2017.09.025

The data on this page was last updated at 04:58 on April 25, 2019.