Normal and pathologic anatomy of the lumbar root canals

Area of Science:

• Orthopedics
• Anatomy
• Radiology

Background:

• Degenerative changes in the lumbar spine are common.
• The complex 3D anatomy of lumbar root canals is challenging to visualize.
• Understanding these changes is vital for diagnosing spinal stenosis and radiculopathy.

Purpose of the Study:

• To detail the complex three-dimensional anatomical changes in degenerated human lumbar spines.
• To investigate the impact of degenerative changes on nerve root and vascular structures.
• To highlight the importance of segmental blood circulation in lumbar spine degeneration.

Main Methods:

• Surface cryoplaning technique applied to 83 degenerated human lumbar spines (274 segments).
• Detailed imaging in axial, sagittal, and coronal planes.
• Functional positioning and arterial contrast injection were utilized in some specimens.

Main Results:

• Identified bulging intervertebral discs, annulus fibrosus retropulsion, and vertebral endplate ridges.
• Observed osteophytosis, cartilage erosion, ligamentum flavum buckling, and synovial fold derangement in facet joints.
• Demonstrated significant nerve root and radicular vessel encroachment during extension and rotation.

Conclusions:

• No single orthogonal plane adequately displays lumbar root canal anatomy.
• Degenerative changes significantly encroach upon neural and vascular structures.
• Segmental blood circulation plays a critical role in lumbar spine degeneration and associated pathologies.