Physical and chemical aspects of calcium phosphates used in spinal surgery

Bohner, Marc

doi:10.1007/s005860100276

Cited by 141 publications

(66 citation statements)

References 36 publications

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“…When the polymer chains cross-linked, the polymer chains lost the ability of free movement. Compressive strength values of injectable CaP reported in the literature range from few MPa [33] up to 83 MPa [34] and these values are based on the method of testing and CaP compositon.…”

Section: Discussionmentioning

confidence: 99%

Cross-linked chitosan improves the mechanical properties of calcium phosphate–chitosan cement

Aryaei

Liu

Jayatissa

et al. 2015

Materials Science and Engineering: C

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Calcium phosphate (CaP) cements are highly applicable and valuable materials for filling bone defects by minimally invasive procedures. Chitosan (CS) biopolymer is also considered as one of the promising biomaterial candidates in bone tissue engineering. In the present study, some key features of CaP-CS were significantly improved by developing a novel CaP-CS composite. For this purpose, CS was the first cross-linked with tripolyphosphate (TPP) and then mixed with CaP matrix. A group of CaP-CS samples without cross-linking was also prepared. Samples were fabricated and tested based on the known standards. Additionally, the effect of different powder (P) to liquid (L) ratios was also investigated. Both cross-linked and uncross-linked CaP-CS samples showed excellent washout resistance. The most significant effects were observed on Young's modulus and compressive strength in wet condition as well as surface hardness. In dry conditions, the Young's modulus of cross-linked samples were slightly improved. Based on the presented results, cross-linking does not have significant effect on porosity. As expected, by increasing the P/L ratio of sample, ductility and injectabilty were decreased. However, in the most cases, mechanical properties were enhanced. The results have shown that cross-linking can be improved the mechanical properties of CaP-CS and hence it can be used for bone tissue engineering applications.

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Section: Discussionmentioning

confidence: 99%

Cross-linked chitosan improves the mechanical properties of calcium phosphate–chitosan cement

Aryaei

Liu

Jayatissa

et al. 2015

Materials Science and Engineering: C

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“…There have also been considerable efforts to improve the mechanical properties and the delivery of CaP cements5,6,20,39 in an attempt to develop a superior, osteoconductive alternative to PMMA, for use in vertebroplasty. In contrast, few groups have used FE modeling to investigate the effects of vertebroplasty on the biomechanics of the traumatically injured spine.…”

Section: Discussionmentioning

confidence: 99%

Experimental and Computational Approach Investigating Burst Fracture Augmentation Using PMMA and Calcium Phosphate Cements

et al. 2014

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The aim of the study was to use a computational and experimental approach to evaluate, compare and predict the ability of calcium phosphate (CaP) and poly (methyl methacrylate) (PMMA) augmentation cements to restore mechanical stability to traumatically fractured vertebrae, following a vertebroplasty procedure. Traumatic fractures (n = 17) were generated in a series of porcine vertebrae using a drop-weight method. The fractured vertebrae were imaged using μCT and tested under axial compression. Twelve of the fractured vertebrae were randomly selected to undergo a vertebroplasty procedure using either a PMMA (n = 6) or a CaP cement variation (n = 6). The specimens were imaged using μCT and re-tested. Finite element models of the fractured and augmented vertebrae were generated from the μCT data and used to compare the effect of fracture void fill with augmented specimen stiffness. Significant increases (p < 0.05) in failure load were found for both of the augmented specimen groups compared to the fractured group. The experimental and computational results indicated that neither the CaP cement nor PMMA cement could completely restore the vertebral mechanical behavior to the intact level. The effectiveness of the procedure appeared to be more influenced by the volume of fracture filled rather than by the mechanical properties of the cement itself.

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“…Therefore, the setting time of formulations made of MCPM + a basic calcium orthophosphate increases in the order: HA > β-TCP > α-TCP [4,5]. For example, HA + MCPM mixtures have a setting time of several minutes, β-TCP + MCPM mixtures—of 30 to 60 s and α-TCP + MCPM mixtures—of a few seconds [173,174].…”

Section: Two Major Types Of the Self-setting Calcium Orthophosphatmentioning

confidence: 99%

“…When the P/L ratio is high, the porosity of the hardened formulations is low [4,5]. According to calculations, the tensile strength of the formulations with zero porosity could be as high as 103 MPa [164].…”

Section: The Mechanical Propertiesmentioning

confidence: 99%

Self-Setting Calcium Orthophosphate Formulations

Dorozhkin¹

2013

JFB

152

107

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In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are bioactive and biodegradable grafting bioceramics in the form of a powder and a liquid. After mixing, both phases form pastes, which set and harden forming either a non-stoichiometric calcium deficient hydroxyapatite or brushite. Since both of them are remarkably biocompartible, bioresorbable and osteoconductive, self-setting calcium orthophosphate formulations appear to be promising bioceramics for bone grafting. Furthermore, such formulations possess excellent molding capabilities, easy manipulation and nearly perfect adaptation to the complex shapes of bone defects, followed by gradual bioresorption and new bone formation. In addition, reinforced formulations have been introduced, which might be described as calcium orthophosphate concretes. The discovery of self-setting properties opened up a new era in the medical application of calcium orthophosphates and many commercial trademarks have been introduced as a result. Currently such formulations are widely used as synthetic bone grafts, with several advantages, such as pourability and injectability. Moreover, their low-temperature setting reactions and intrinsic porosity allow loading by drugs, biomolecules and even cells for tissue engineering purposes. In this review, an insight into the self-setting calcium orthophosphate formulations, as excellent bioceramics suitable for both dental and bone grafting applications, has been provided.

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Physical and chemical aspects of calcium phosphates used in spinal surgery

Cited by 141 publications

References 36 publications

Cross-linked chitosan improves the mechanical properties of calcium phosphate–chitosan cement

Cross-linked chitosan improves the mechanical properties of calcium phosphate–chitosan cement

Experimental and Computational Approach Investigating Burst Fracture Augmentation Using PMMA and Calcium Phosphate Cements

Self-Setting Calcium Orthophosphate Formulations

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