Biomechanical in Vitro and Finite Element Study On Different Sagittal Alignment Postures of the Lumbar Spine During Multiaxial Daily Motion

Journal of Biomechanical Engineering, vol. 144

Abstract

Lumbar lordotic correction (LLC), the gold standard treatment for sagittal spinal malalignment (SMA), and its effect on sagittal balance have been critically discussed in recent studies. This paper assesses the biomechanical response of the spinal components to LLC as an additional factor for the evaluation of LLC. Human lumbar spines (L2L5) were loaded with combined bending moments in flexion (Flex)/extension (Ex) or lateral bending (LatBend) and axial rotation (AxRot) in a physiological environment. We examined the dependency of AxRot range of motion (RoM) on the applied bending moment. The results were used to validate a finite element (FE) model of the lumbar spine. With this model, the biomechanical response of the intervertebral discs (IVD) and facet joints under daily motion was studied for different sagittal alignment postures, simulated by a motion in Flex/Ex direction. Applied bending moments decreased AxRot RoM significantly (all P < 0.001). A stronger decline of AxRot RoM for Ex than for Flex direction was observed (all P < 0.0001). Our simulated results largely agreed with the experimental data (all R2 > 0.79). During the daily motion, the IVD was loaded higher with increasing lumbar lordosis (LL) for all evaluated values at L2L3 and L3L4 and posterior annulus stress (AS) at L4L5 (all P < 0.0476). The results of this study indicate that LLC with large extensions of LL may not always be advantageous regarding the biomechanical loading of the IVD. This finding may be used to improve the planning process of LLC treatments.

Authors 10

1. Nadja Wilmanns corresponding Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstraße 18, 52062 Aachen

2. Agnes Beckmann Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstraße 18, 52062 Aachen

3. Luis Fernando Nicolini Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstraße 18, 52062 Aachen

4. Christian Herren Aachen Department for Trauma and Reconstructive Surgery

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department for Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074 Aachen

5. Rolf Sobottke
   Affiliation as printed

   Rhein-Maas Klinik, Department of Orthopaedics and Trauma Surgery, Mauerfeldchen 25, 52146 Würselen

6. Frank Hildebrand Aachen Department for Trauma and Reconstructive Surgery

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department for Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074 Aachen

7. Jan Siewe

   University of Cologne · University Hospital Cologne · Klinikum Leverkusen

   Affiliation as printed

   Department of Spine Surgery, Klinikum Leverkusen gGmbH, Am Gesundheitspark 11, 51375 Leverkusen; Faculty of Medicine, University Hospital of Cologne, Joseph-Stelzmann-Str. 20, 50931 Köln

8. Philipp Kobbe Aachen Department for Trauma and Reconstructive Surgery

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department for Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074 Aachen

9. Bernd A. Markert Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstraße 18, 52062 Aachen

10. Marcus Stoffel Aachen Institute of General Mechanics

    RWTH Aachen University

    Affiliation as printed

    Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstraße 18, 52062 Aachen