PURPOSE: To investigate the effects of a clinical @entity154 on the structural response of @entity1 thoracolumbar functional spinal unit. METHODS: A novel CT-compatible mechanical test system was used to image the deformation of a T12-L1 motion segment and measure the change in strain response under compressive loads ranging from 50 to 750N. A @entity75 (LM) with cortex involvement (33% by volume) was introduced to the upper vertebral body and the CT experiments were repeated. Finite element models, established from the CT volumes, were used to investigate the defect's effects on the structural response and the state of principal and shear stresses within the affected and adjacent vertebrae. RESULTS: The lesion caused significant, non-linear and asymmetric increase in the experimentally measured strains and computed stresses within both vertebrae (p   <   0.01). Experimental tensile strains at the cortex significantly increased, while compressive strains significantly decreased, (p   <   0.05). Both the vertebral bone and cortex regions adjacent to the defect showed significant increase in computed compressive, tensile and shear stresses (p   <   0.01). Although the effect of LM on the global deformation of the spine was well-predicted, our results show that FE predictions of local strain changes must be carefully assessed for clinical relevance. CONCLUSIONS: The @entity75 resulted in severe loss of the vertebral structural competence. Changes in stress and strain distribution within the affected and adjacent vertebral bone and the experimentally observed bulging and buckling of the vertebral cortices, suggested that initiation of catastrophic @entity177 may occur under load magnitudes encountered in daily living. This article is protected by copyright. All rights reserved.

Mechanical assessment of the effects of metastatic XXXX on the structural response of @entity1 thoracolumbar spine.

@entity1 :: ('9606', 'Species') :: ['human'] @entity154 :: ('MESH:D000013', 'Disease') :: ['lytic defect'] @entity177 :: ('MESH:D051437', 'Disease') :: ['vertebral failure'] @entity75 :: ('MESH:D001927', 'Disease') :: ['lytic lesion']
@entity154 :: (MESH:D000013,Disease) :: ['lytic defect']
