Degeneration alters structure-function relationships at multiple length-scales and across interfaces in human...

Area of Science:

• Biomedical Engineering
• Orthopedics
• Regenerative Medicine

Background:

• Intervertebral disc (IVD) degeneration causes significant back pain and functional loss.
• Degeneration involves cellular, compositional, and structural changes across the disc, endplates, and vertebrae.
• Previous studies often focused on single attributes, hindering a holistic understanding of degeneration.

Purpose of the Study:

• To conduct a multiscale and multimodal analysis of human lumbar motion segments.
• To identify correlations between structural and functional measurements of IVD subcomponents.
• To investigate the interplay between vertebral bone, cartilage endplate (CEP), and nucleus pulposus (NP) during degeneration.

Main Methods:

• Multiscale and multimodal analysis of human lumbar motion segments.
• Performed multiple assays on each sample to assess various IVD attributes.
• Utilized imaging and mechanical testing across different length scales.

Main Results:

• Increasing Pfirrmann grade correlated with reduced disc height and NP T2 relaxation time.
• Observed alterations in motion segment macromechanical function, matrix composition, and cellular morphology.
• Significant remodeling and altered micromechanical properties were noted at the cartilage endplate-vertebral bone interface.

Conclusions:

• IVD degeneration is a complex, interconnected process affecting the entire motion segment.
• Significant relationships exist between vertebral bone, NP metrics, and endplate micromechanics.
• A holistic, organ-level approach is essential for understanding and potentially treating IVD degeneration.