Three-dimensional architecture of lumbar intervertebral discs

Area of Science:

• Biomedical Engineering
• Anatomy
• Biomaterials Science

Background:

• The intricate collagenous structure of the lumbar intervertebral disc (LIVD) is crucial for spinal biomechanics.
• Understanding the precise architectural relationships within the LIVD is essential for diagnosing and treating disc degeneration.

Purpose of the Study:

• To elucidate the three-dimensional collagen framework of the lumbar intervertebral disc using scanning electron microscopy.
• To detail the architectural interconnections between the annulus fibrosus, cartilage end-plate, and vertebral bodies.

Main Methods:

• Three-dimensional observations were conducted using scanning electron microscopy (SEM).
• The collagenous framework of the annulus fibrosus and cartilage end-plate was analyzed.
• Interconnections with subchondral collagen and vertebral bodies were examined.

Main Results:

• The fibrillar framework of the annulus and cartilage end-plate forms a closed pack system originating from the nucleus.
• The cartilage end-plate exhibits a dense, horizontally aligned collagen framework with no direct connection to lamellar subchondral collagen.
• Outer annulus fibrosus lamellae are anchored into vertebral bodies, while inner lamellae interconnect with the cartilage end-plate.

Conclusions:

• The lumbar intervertebral disc collagen framework exhibits a unique, organized architecture.
• Distinct structural arrangements exist between the cartilage end-plate, annulus fibrosus, and vertebral bodies.
• These findings provide a detailed anatomical basis for understanding disc mechanics and pathology.