Research Article
Kyphoplasty of Osteoporotic Fractured Vertebrae: A Finite
Element Analysis about Two Types of Cement
Carolin Meyer
1
, Kerstin van Gaalen
2
, Tim Leschinger
1
, Max J. Scheyerer
1
,
Wolfram F. Neiss
3
, Manfred Staat
4
, Lars P. Müller
1
, and Kilian Wegmann
1
1
University Hospital of Cologne, Department of Orthopedics and Trauma Surgery, Kerpener Straße 62, 50937 Cologne, Germany
2
College of Biomedical Engineering, RWTH Aachen, Templergraben 55, 52056 Aachen, Germany
3
University of Cologne, Institute of Anatomy, Joseph-Stelzmann Str. 9, 50931 Cologne, Germany
4
University of Applied Science, FH Aachen, Heinrich-Mußmann Str. 1, 52428 J¨ ulich, Germany
Correspondence should be addressed to Carolin Meyer; carolin.meyer@uk-koeln.de
Received 13 January 2019; Accepted 9 April 2019; Published 22 April 2019
Academic Editor: Nicholas Dunne
Copyright © 2019 Carolin Meyer et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
If conservative treatment of osteoporotic vertebral compression fractures fails, vertebro- or kyphoplasty is indicated. Usually,
polymethylmethacrylate cement (PMMA) is applied coming along with many disadvantageous features. Aluminum-free glass-
polyalkenoate cement (GPC) appears to be a beneft alternative material. Tis study aimed at comparing the mean stress values in
human vertebrae afer kyphoplasty with PMMA and GPC (IlluminOss6) at hand of a fnite element analysis. Tree models were
created performing kyphoplasty using PMMA or IlluminOss6, respectively, at two native, human lumbar vertebrae (L4) while one
remains intact. Finite element analysis was performed using CT-scans of every vertebra. Moreover the PMMA-treated vertebra was
used as a model as analyses were executed using material data of PMMA and of GPC. Te unimpaired, spongious bone showed
potentials of 0.25 MPa maximally. Afer augmentation stress levels showed fvefold increase, rising from externally to internally,
revealing stress peaks at the ventral border of the spinal canal. At central areas of cement 1 MPa is measured in both types of
cement. Around these central areas the von Mises stress decreased about 25-50% (0.5-0.75 MPa). If workload of 500 N was applied,
the stress appeared to be more centralized at the IlluminOss6-model, similar to the unimpaired. Considering the endplates the
GPC model also closely resembles the unimpaired. Comparing the PMMA-treated vertebral body and the GPC-simulation, there
is an obvious diference. While the PMMA-treated model showed a central stress peak of 5 MPa, the GPC-simulation of the same
vertebral body presents lower stress of 1.2-2.5 MPa. Finite element analysis showed that IlluminOss6 (GPC), used in kyphoplasty
of vertebral bodies, creates lower level stress and strain compared to standardly used PMMA, leading to lower stress concentrations
on the cranial and caudal vertebral surface especially. GPC appears to own advantageous biological and clinical relevant features.
1. Introduction
Osteoporosis related fractures of the spinal column lead to
pain and functional limitations, or even resulting in confne-
ment to bed [1]. Due to the commonly wedge-shaped collaps-
ing pattern of osteoporotic vertebral compression fractures
(VCF) imbalanced kyphosis may occur, leading to loss of
sagittal balance, chronic pain, and potentially resulting in
decreased lung capacity and gastro-intestinal dysfunction [2,
3]. Controversial discussion about the appropriate individual
treatment of VCF persists [4]. According to the treatment
guidelines of Anselmetti et al. surgical treatment should be
performed, if conservative treatment fails [5]. If the vertebral
body is already deformed, kyphoplasty aims at correction of
the vertebral shape in order to reduce pain and disability and
to restore sagittal balance [1, 4–7].
It is commonly known that, besides shape of the fractures,
the elastic modulus of the fracture region and of the imple-
mented bone cement are important variables infuencing
short- and long-term outcome afer kyphoplasty [8].
Commonly, polymethylmethacrylate cement (PMMA) is
applied to the vertebra at kyphoplasty, in order to support ver-
tebral structure. PMMA however comes along with specifc
disadvantageous characteristics. PMMA generates signifcant
Hindawi
BioMed Research International
Volume 2019, Article ID 9232813, 7 pages
https://doi.org/10.1155/2019/9232813