McKay Orthopaedic Research Laboratory > Elliott Lab > Intervertebral Disc Degeneration and Restoration

Intervertebral Disc Degeneration and Restoration

We hypothesize that early nucleus pulposus chemical and structural degeneration alter disc mechanics and contribute to progressive degeneration. We have used mice, rats, and sheep to test hypotheses for disc function and mechanisms of degeneration. Furthermore, treatments aimed to restore disc function are evaluated in animal models and in human cadaveric mechanical tests.

1. Mouse - We have validate the rodent as an appropriate animal model of human disc mechanics. We have quantified structure-function relationships using transgenic mice. This was the first disc mechanics study in a transgenic mouse and demonstrated an inferior material in the outer annulus in torsion, while compensatory geometry alterations maintained normal structural properties.
2. Rat - We have demonstrated altered neutral zone mechanics that simulate early human degeneration in the rat lumbar spine by injecting agents into the nucleus pulposus that cause both fibrosity and pressure loss.
3. Sheep - We have shown that healthy disc mechanical behaviors are restored following cyclic loading and unloaded recovery, and that viscoelastic changes are permanent following a partial nucleotomy to model proteoglycan loss.