PhD Scientific Days 2023

Clinical Medicine III.

The possible accelerating effect of cranial endplate damaging screws in severe adjacent disc degeneration - a finite element assisted study

Előadó neve

Pokorni, Ágoston Jakab

Neptun code

YEU5AU

Előadó munkahelye

National Center for Spinal Disorders

Előadó telefonszáma

+36306776269

Előadó e-mail címe

pokorni.agoston@gmail.com

Az előadás címe

The possible accelerating effect of cranial endplate damaging screws in severe adjacent disc degeneration - a finite element assisted study

Szerző(k) neve és munkahelye

Ágoston Jakab Pokorni1,2, Ferenc Bereczki1,2, Máté Turbucz1,2, Zoltán Hoffer3, Péter Éltes2,4, Áron Lazáry2,4
1 School of PhD Studies, Semmelweis University, Budapest
2 In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest
3 National Center for Spinal Disorders, Budapest
4 Department of Spine Surgery, Department of Orthopaedics, Semmelweis University, Budapest

Bemutatás módja

Szóbeli

Szekció

Clinical Medicine III.

Language of the presentation

Hungarian

Preferred session

Clinical Medicine

Összefoglaló szövege

Introduction: In spinal fusion surgeries, cranial fusion extension is used to treat adjacent segment degeneration where the pathology greatly impairs the patient’s quality of life.
Aims: This study aimed to investigate if the use of cranial endplate damaging screws during lumbar spine fusion surgeries promotes adjacent disc degeneration, using a patient cohort and finite element modeling.
Method: The study analyzed 199 cases of cranial fusion-extension surgeries at National Center for Spinal Disorders, Budapest between 2012 and 2020. The cases were divided into two groups based on postoperative x-ray scans, with Group 1 (Cranial Screw Position) having screws bordering or penetrating the cranial endplate and Group 2 (Parallel Screw Position) having screws in other positions. The time elapsed between the index and cranial fusion-extension surgeries was also assessed. Finite Element Models (FEMs) of the lumbar spine with different levels of posterior fixation (L2-L3, L2-L4, L2-L5) and positions of pedicle screws (CSP, PSP) in the L2 vertebra were also constructed. The models were compared for the same displacement using the range of motion (ROM) of the two-level fixation models (L2-L4) against a 400 N follower load and a 7.5 Nm bending moment in flexion, lateral bending, and axial rotation. The distributions and maximums of von Mises stress in the endplates were investigated for every model.
Results: The minimum, the maximum, and the median of the time between the index and the cranial fusion-extension surgery were 75, 1840, and 397 days in Group 1 and 49, 4045, and 974 in Group 2, respectively. There was a statistically significant difference (P<0.005) between Group 1 and Group 2 in the median of the days between the two surgeries. The CSP resulted in larger high-stressed areas and higher stress peaks in the ROI for any load case and level of fixation than the PSP.
Conclusion: Based on the investigated cohort, the CSP required reoperation earlier than the PSP, suggesting that the screw position accelerates adjacent disc degeneration. Furthermore, finite element results showed that both the level of fixation and the screw position deeply impacts the stress distributions in the central part of the bony endplate, the CSP providing substantially higher stress peaks.
Funding: No funding was used.

University and Doctoral School

Semmelweis University, Károly Rácz Doctoral School of Clinical Medicine

Supervisor

Péter Éltes and Áron Lazáry

Publication of my abstract

I do not give consent to the publication of my abstract on the website of the congress.

Kind

Szabad

Status

elfogadva

Accepted presentation method

szóbeli

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

7407

Start

09:30

End

09:45

Authors (legacy)

Ágoston Jakab Pokorni1,2, Ferenc Bereczki1,2, Máté Turbucz1,2, Zoltán Hoffer3, Péter Éltes2,4, Áron Lazáry2,4
1 School of PhD Studies, Semmelweis University, Budapest
2 In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest
3 National Center for Spinal Disorders, Budapest
4 Department of Spine Surgery, Department of Orthopaedics, Semmelweis University, Budapest