Differences in trabecular bone, cortical shell, and endplate microstructure across the lumbar spine

Palepu, Vivek<sup>1</sup>; Rayaprolu, Sai Deepa<sup>1</sup>; Nagaraja, Srinidhi<sup>1</sup>

Affiliations

¹US Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Applied Mechanics, Silver Spring, Maryland

Abstract and keywords

Background: The quality of the vertebral body structures such as endplate, cortex, and trabecular bone is important for understanding the performance of implants, particularly at the bone-implant interface. Although vertebral body structures have been analyzed separately in the literature, there is no comprehensive study to assess these anatomical measurements along with their interrelationships in the lumbar spine. Therefore, the purpose of this study was to assess variations in trabecular microstructure, vertebral endplate thickness and concavity, and vertebral body cortex thickness within the lumbar spine.

Methods: A total of 80 lumbar vertebrae (L1-L5) were dissected from 16 human cadaver specimens and imaged with microcomputed tomography to determine trabecular microstructure, vertebral cortex thickness, endplate thickness, and maximum endplate concavity depth. A paired t test and regression analysis were used to determine significant differences (P < .05) between different vertebral levels and correlations between the analyzed anatomical parameters.

Results: L1 vertebra had significantly better (P < .02) trabecular bone microstructure (eg, trabecular bone volume fraction) than all other lumbar vertebrae. However, L1 vertebra also had significantly thinner (P ≤ .02) anterior, left, and right cortices compared to all other vertebral levels. Within L3-L5 intervertebral disc spaces, cranial endplates had significantly greater (P ≤ .03) thickness and maximum concavity depth compared to their respective caudal endplates. No strong correlations were observed between trabecular bone microstructure, maximum endplate concavity depth, vertebral cortex, and endplate thickness parameters.

Conclusions: Detailed reference data of these anatomical parameters for each lumbar vertebral body can aid in improved understanding of bone quality, particularly when assessing different implant designs and fixation approaches. Moreover, such anatomical knowledge may help clinicians with optimal implant design selection and surgical placement of these devices into their respective locations.

Keywords: endplate concavity depth; trabecular bone microstructure; vertebral cortex thickness; endplate thickness; lumbar spine; anatomy

Links

DOI: 10.14444/6049

PubMed: 31531286

WoS: 000484340800008

History

Online: 2019-08-31

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Cited By (2)

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2022	Yeni YN, Dix MR, Xiao A, Oravec DJ, Flynn MJ. Measuring the thickness of vertebral endplate and shell using digital tomosynthesis. Bone. April 2022;157:116341.
2020	Auger JD, Frings N, Wu Y, Marty AG, Morgan EF. Trabecular architecture and mechanical heterogeneity effects on vertebral body strength. Curr Osteoporos Rep. December 2020;18(6):716-726.