Etiology of disc degeneration relation to low back pain.
Smith SD; Lafferty JF; Winter WG
NIOSH 1979 Aug; :1-8
The etiology of disc degeneration related to low back pain was studied in Macaca-mulatta or Cynomologus-iris-monkeys. Pieces of surgical tubing were implanted between vertebrae to compress the vertebral disc for 90 days, and the lumbar spine was then examined. Some of the experimental animals were also injected with tracers to determine diffusion from the disc and protein metabolism, and intradisc pressure was measured in other experimental animals. Pressures greater than 0.46 kilograms per square centimeter on the disc produced progressive loss of the fibrocellular interface between disc and endplate, and a progressive and significant compression of the endplate. Equivalent pressure on the annulus fibrosis region caused loss of polysaccharide and nuclear herniation in six animals. Compressed disc endplates showed a marked increase in pyknotic chondrocytes. No difference in control disc and compressed disc diffusion rate occurred, but compressed discs did not incorporate labeled material uniformly or well; hyaline endplate and annulus cells were almost devoid of labeling. Compressed disc did not incorporate proline, demonstrating marked interference with protein metabolism. Immediately after surgical banding, pressure in the compressed disc rose to 1500 millimeters of mercury, but pressure returned to normal within 30 minutes. The authors conclude that the monkey provides a good animal model of stress induced intervertebral disc degeneration, and that disc degeneration has morphological and physiological effects.
NIOSH-Grant; Life-sciences; Back-injuries; Skeletal-system; Spinal-cord; Animal-studies; Models; Medical-research; Skeletal-system-disorders
Mechanical Engineering University of Kentucky Lexington, KY 40506 Lexington, KY 40506
Final Grant Report
University of Kentucky, Lexington, Kentucky, NIOSH
University of Kentucky, Lexington, Kentucky