Etiology of Disc Degeneration Related to Low Back Pain

摘要

An animal model of stress-induced intervertebral disc degeneration was developed to verify whether degeneration changes morphological, physiological and material properties of the disc, and to verify whether degeneration causes painful disability. The animal model was developed with Rhesus-monkeys and then Cynomologus-monkeys, the change being necessitated due to difficulties in supplying animals for study. A repeatable degree of disc degeneration could be produced surgically in these animal models when known time and stress parameters were available. The animals were sacrificed 90 days after surgery and the lumbar spine removed for examination. Preliminary studies indicated that compressed discs lose some of their important viscoelastic properties, making them susceptible to high rate loading damage. Increased pressure caused the progressive loss of the fibro/cellular interface between disc and endplate. In late stages the animals appeared to be uncomfortable and they reduced their activity level, but severe pain did not appear to be evident.