uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Biomechanics of low-modulus and standard acrylic bone cements in simulated vertebroplasty: A human ex vivo study
University of Leeds.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. (Materials in Medicine)
University of Leeds.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. (Materials in Medicine)
Show others and affiliations
2015 (English)In: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 48, no 12, 3258-3266 p.Article in journal (Refereed) Published
Abstract [en]

The high stiffness of bone cements used in vertebroplasty has been hypothesised to contribute to the propensity of adjacent vertebral fractures after treatment. Therefore, new low-modulus cements have been developed; however, there are currently no studies assessing the biomechanical aspects of vertebroplasty with these cements in an ex vivo non-prophylactic model. In this study, we induced wedge fractures through eccentric uniaxial compression to single whole-vertebrae, before and after augmentation with either standard or low-modulus cement. Compressive strength and stiffness of individual vertebrae were measured, on 19 samples from metastatic spines and 20 samples from elderly, osteopenic spines. While both cement types increased the strength of both the metastatic (+34% and +63% for standard and low-modulus cement, respectively) and the elderly vertebrae (+303% and +113%, respectively), none of them restored the initial stiffness of metastatic specimens (−51% and −46%, respectively). Furthermore, low-modulus cement gave a lower total stiffness (−13%) of elderly specimens whereas standard cement increased it above initial levels (+17%). Results show that vertebroplasty with low-modulus cement could provide restoration of the initial stiffness while increasing the strength of fractured elderly vertebrae and hence represent a treatment modality which is closer to pre-augmented behaviour. Also, this study indicates that stiffness-modified cement needs to be optimised for patient/pathology specific treatment.

Place, publisher, year, edition, pages
2015. Vol. 48, no 12, 3258-3266 p.
Keyword [en]
vertebroplasty, PMMA, low-modulus cement(s), adjacent vertebral fracture(s), osteoporosis, metastasis, wedge compression fracture(s)
National Category
Biomaterials Science Engineering and Technology
Research subject
Engineering Science with specialization in Materials Science
URN: urn:nbn:se:uu:diva-213226DOI: 10.1016/j.jbiomech.2015.06.026ISI: 000363069900045OAI: oai:DiVA.org:uu-213226DiVA: diva2:681330
EU, FP7, Seventh Framework ProgrammeVINNOVA, VINNMER 2010-02073
Available from: 2013-12-19 Created: 2013-12-19 Last updated: 2016-01-29Bibliographically approved
In thesis
1. Injectable Biomaterials for Spinal Applications
Open this publication in new window or tab >>Injectable Biomaterials for Spinal Applications
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The use of injectable biomaterials is growing as the demands for minimally invasive procedures, and more easily applicable implants become higher, but their availability is still limited due to the difficulties associated to their design.

Each year, more than 700,000 vertebral compression fractures (VCF’s) are reported in the US and 500,000 VCF’s in Europe due to primary osteoporosis only. VCF’s can compromise the delicacy of the spinal canal and also cause back pain, which affects the patient’s quality of life. Vertebroplasty was developed in the 80’s, and has proven to be a safe minimally invasive procedure that can, quickly and sustainably, relieve the pain in patients experiencing VCF’s. However, biomaterials for vertebroplasty still have limitations. For instance, ceramic bone cements are difficult to distinguish from the bone using X-ray techniques. On the other hand, acrylic bone cements may cause adjacent vertebral fractures (AVF’s). Large clinical studies have indicated that 12 to 20% vertebroplasty recipients developed subsequent vertebral fractures, and that 41 to 67% of these, were AVF’s. This may be attributed to the load shifting and increased pressure on the adjacent endplates reached after vertebroplasty with stiff cements.

The primary aim of this thesis was to develop better injectable biomaterials for spinal applications, particularly, bone cements for vertebroplasty. Water-soluble radiopacifiers were first investigated to enhance the radiopacity of resorbable ceramic cements. Additionally, different strategies to produce materials that mechanically comply with the surrounding tissues (low-modulus bone cements) were investigated. When a suitable low-modulus cement was produced, its performance was evaluated in both bovine bone, and human vertebra ex vivo models.

In summary, strontium halides showed potential as water-soluble radiocontrast agents and could be used in resorbable calcium phosphates and other types of resorbable biomaterials. Conversely, linoleic acid-modified (low-modulus) cements appeared to be a promising alternative to currently available high-modulus cements. It was also shown that the influence of the cement properties on the strength and stiffness of a single vertebra depend upon the initial bone volume fraction, and that at low bone volume fractions, the initial mechanical properties of the vertebroplasty cement become more relevant. Finally, it was shown that vertebroplasty with low-modulus cements is biomechanically safe, and could become a recommended minimally invasive therapy in selected cases, especially for patients suffering from vertebral compression fractures due to osteoporosis.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. 66 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1114
injectable, biomaterials, bone cement, vertebral compression fractures, spine, radiopacity, minimally invasive treatment, low-modulus cement, oligomer, PMMA, calcium phosphate, vertebroplasty, bone
National Category
Biomaterials Science
Research subject
Engineering Science with specialization in Materials Science
urn:nbn:se:uu:diva-215606 (URN)978-91-554-8854-3 (ISBN)
Public defence
2014-02-28, Polhemssalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:00 (English)
Available from: 2014-02-05 Created: 2014-01-15 Last updated: 2014-02-10

Open Access in DiVA

The full text will be freely available from 2019-07-16 00:00
Available from 2019-07-16 00:00

Other links

Publisher's full text

Search in DiVA

By author/editor
López, AlejandroEngqvist, HåkanPersson, Cecilia
By organisation
Applied Materials Sciences
In the same journal
Journal of Biomechanics
Biomaterials ScienceEngineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 573 hits
ReferencesLink to record
Permanent link

Direct link