End-plate displacement during compression of lumbar vertebra-disc-vertebra segments and the mechanism of failure.
Seventeen specimens of lumbar discs, attached to the caudal and cranial halves of the adjacent vertebral bodies, were subjected to a maximum compressive load of 5.5 kN in six stages. The time between each stage was about 15 seconds. At each stage of compression, a radiograph of the specimen was recorded, and the bulging of the end-plate into the caudal vertebra was measured using a displacement transducer. After compression, the ash content of a bone sample and the water content of a sample of the nucleus of the disc were measured for each specimen. Sections through the specimens were examined by light microscopic study. Eight specimens did not fail, although end-plate displacement occurred during compression. The remaining nine specimens experienced fracture or permanent deformation of the end-plate. Specimens that failed had significantly lower rigidity of the end-plate and underlying trabecular bone; this rigidity was correlated with bone ash content.
Holmes
A D
AD
Department of Medical Biophysics, University of Manchester, England.
Hukins
D W
DW
Freemont
A J
AJ
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000502:physiology*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016474:Weight-Bearing / Q000502:physiology