Seeing double: a comparison of microstructure, biomechanical function, and adjacent disc health between double- and single-layer vertebral endplates.

Study Design: Experimental and computational assessment of thickness, porosity, biomechanical behavior, and adjacent disc glycosaminoglycan content in double- and single-layer bony endplate samples harvested from human cadaver spines.

Objective: To determine if the second layer of bone in double-layer vertebral endplates allows the superficial layer to achieve a more optimal balance between its biomechanical and nutritional functions.

Summary Of Background Data: Proper disc health requires the endplate to balance opposing biomechanical and nutritional functions.

Morphology of the human vertebral endplate.

It is presumed that poor intervertebral disc cell nutrition is a contributing factor in degeneration, and is exacerbated by vertebral endplate sclerosis. Yet, quantitative relationships between endplate morphology and degeneration are unavailable. We investigated how endplate bone microstructure relates to indices of disc degeneration, such as morphologic grade, proteoglycan content, and cell density.

Human disc nucleus properties and vertebral endplate permeability.

Study Design: Experimental quantification of relationships between vertebral endplate morphology, permeability, disc cell density, glycosaminoglycan (GAG) content, and degeneration in samples harvested from human cadaveric spines.

Objective: To test the hypothesis that variation in endplate permeability and porosity contributes to changes in intervertebral disc cell density and overall degeneration.

Summary Of Background Data: Cells within the intervertebral disc are dependent on diffusive exchange with capillaries in the adjacent vertebral bone.

Mechanical profiling of intervertebral discs.

Despite recent advances in imaging diagnostic technology and additional treatment options our ability to prevent or inhibit discogenic back pain has not drastically improved. The challenge of linking early degenerative patterns to dysfunction and pain remains. Using a novel material testing device designated the tissue diagnostic instrument (TDI) we measured the local stiffness and strain energy absorption in the radial direction of 13 intact intervertebral discs; effectively generating a mechanical profile of each disc.

Stab incision for inducing intervertebral disc degeneration in the rat.

Study Design: The degenerative response of rat tail and lumbar intervertebral discs to a stab incision was evaluated.

Objective: To examine and compare the postinjury degenerative response of lumbar and tail discs.

Summary Of Background Data: Although successful in larger animals, a stab incision for inducing disc degeneration in rats has not been evaluated.