Intervertebral foramen narrowing during vertical dynamic loading

Abstract

Objective

The goal of the present study was to examine the effect of vertebral body fracture on the InterVertebral Foraminal IVF parameters with an input acceleration to the seat bottom in the inferior-to-superior direction.

Methods

A series of 43 isolated lumbar spines underwent vertical dynamic loading using the vertical accelerative device to determine the influence of inferior to superior loading through the lumbar spine on the intervertebral foramen (IVF) geometries. Existence of foraminal stenosis was quantified using pre- and post-test computed tomography (CT) images. Foraminal height (IVF_Ht) and posterior disk height (PD_Ht) were the key IVF parameters.

Results

There was a significant (p < 0.05) decrease in the post-test IVF measurements compared to the pretest measurements. Furthermore, 30% of the total 49 AIS 2 cases and 70% of the total 21 AIS 3 cases had IVF values below the literature reported thresholds for IVF_Ht of < 15 mm and PD_Ht of < 4 mm, indicating likely occurrence of foraminal stenosis.

Conclusions

These results underscore the need to assess foraminal geometry in compression fractures of the lumbar spine from vertical dynamic loading.

Keywords:

• Thoracolumbar fractures
• intervertebral foramen
• lumbar radiculopathy

Additional information

Funding

The data used in this study originated from work conducted under the support of contract #N00024-13-D-6400, sponsored by the U.S. Army Research Lab in support of the WIAMan Program. This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs, through the Broad Agency Announcement under Award No. W81XWH-16-1-0010, and the Department of Veterans Affairs Medical Research. The Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense or other sponsors.