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. 2022 Apr;5(2):153-160.
doi: 10.1002/ame2.12213. Epub 2022 Feb 22.

Spinal fixation after laminectomy in pigs prevents postoperative spinal cord injury

Emma M H Slot  1 , Bart de Boer  2 , Saskia Redegeld  3 , Sander van Thoor  3 , Nizar Moayeri  1 , Willem-Bart Slooff  1 , Irene A Schaafsma  4 , Björn Meij  4 , Tristan P C van Doormaal  1   5
Affiliations

Spinal fixation after laminectomy in pigs prevents postoperative spinal cord injury

Emma M H Slot et al. Animal Model Exp Med. 2022 Apr.

Abstract

Background: A safe, effective, and ethically sound animal model is essential for preclinical research to investigate spinal medical devices. We report the initial failure of a porcine spinal survival model and a potential solution by fixating the spine.

Methods: Eleven female Dutch Landrace pigs underwent a spinal lumbar interlaminar decompression with durotomy and were randomized for implantation of a medical device or control group. Magnetic resonance imaging (MRI) was performed before termination.

Results: Neurological deficits were observed in 6 out of the first 8 animals. Three of these animals were terminated prematurely because they reached the predefined humane endpoint. Spinal cord compression and myelopathy was observed on postoperative MRI imaging. We hypothesized postoperative spinal instability with epidural hematoma, inherent to the biology of the model, and subsequent spinal cord injury as a potential cause. In the subsequent 3 animals, we fixated the spine with Lubra plates. All these animals recovered without neurological deficits. The extent of spinal cord compression on MRI was variable across animals and did not seem to correspond well with neurological outcome.

Conclusion: This study shows that in a porcine in vivo model of interlaminar decompression and durotomy, fixation of the spine after lumbar interlaminar decompression is feasible and may improve neurological outcomes. Additional research is necessary to evaluate this hypothesis.

Keywords: fixation; interlaminar decompression; medical device model; spinal cord injury.

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Conflict of interest statement

T.P.C. van Doormaal is a consultant for Polyganics B.V.

Figures

FIGURE 1
FIGURE 1
Intraoperative dorsal view of ILD at one level (L1‐2), showing sutured durotomy. 1, spinous process; 2, dura mater. Scientific illustration by Amanda Gautier
FIGURE 2
FIGURE 2
(A) Lubra plate 14.5 cm with holes to accommodate screw placement and (B) screw, washer, and nut for Lubra plates (0.75 inches long), retrieved from: https://voieurope.com/lubra‐plates‐medium‐pair‐14cm/ and https://voieurope.com/screw‐with‐washer‐nut‐for‐lubra‐plates‐3‐4‐inch‐long/
FIGURE 3
FIGURE 3
Intraoperative dorsal view of 2 Lubra plates applied to the lumbar spine after ILD. 1, spinous process; 3, Lubra plate; 4, screw. Scientific illustration by Amanda Gautier
FIGURE 4
FIGURE 4
(A) Postoperative MRI of the spine (pig 7) showing significant compression (arrow) of the spinal cord at level L4‐5. (B) Postoperative MRI of the spine (pig 1) showing compression (arrows) of the spinal cord at the 3 operated levels, that is, last L1‐L2, L3‐4, and L5‐L6. (C, D) Postoperative MRI of the spine (pigs 9 and 10) showing moderate compression on the operated level, L2‐3 and L1‐2, respectively. Artefacts (*) due to the screws used for fixating the Lubra plates still facilitate assessment of the spinal cord and dura
See this image and copyright information in PMC

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