Differences in Trabecular Bone, Cortical Shell, and Endplate Microstructure Across the Lumbar Spine.

Area of Science:

• Orthopedics
• Anatomy
• Biomaterials Science

Background:

• Vertebral body structure quality (endplate, cortex, trabecular bone) is crucial for implant performance at the bone-implant interface.
• Existing literature analyzes vertebral structures separately, lacking comprehensive interrelationship studies in the lumbar spine.

Purpose of the Study:

• To assess variations in trabecular microstructure, vertebral endplate thickness and concavity, and vertebral body cortex thickness within the lumbar spine.

Main Methods:

• Microcomputed tomography imaging of 80 lumbar vertebrae (L1-L5) from 16 human cadavers.
• Analysis of trabecular microstructure, vertebral cortex thickness, endplate thickness, and endplate concavity depth.
• Paired t tests and regression analysis to determine significant differences and correlations (P < .05).

Main Results:

• L1 vertebra exhibited significantly better trabecular bone microstructure (e.g., bone volume fraction) than other lumbar vertebrae (P < .02).
• L1 vertebra showed significantly thinner anterior, left, and right cortices compared to other levels (P ≤ .02).
• Cranial endplates in L3-L5 intervertebral disc spaces were significantly thicker and more concave than caudal endplates (P ≤ .03).
• No strong correlations were found between trabecular microstructure, endplate concavity, and vertebral cortex/endplate thickness.

Conclusions:

• Provides detailed reference data for lumbar vertebral body anatomical parameters, aiding bone quality assessment for implant designs.
• Enhances understanding of implant fixation and may guide clinicians in selecting optimal implant designs and surgical placement.