Stress relaxation modelling of polymethylmethacrylate bone cement

2002 ◽  
Vol 216 (3) ◽  
pp. 195-199 ◽  
Author(s):  
O R Eden ◽  
A J C Lee ◽  
R M Hooper
Keyword(s):  
Stress Relaxation ◽  
Bone Cement ◽  
Load Transfer ◽  
Femoral Stem ◽  
Maxwell Model ◽  
Mechanical Tests ◽  
Hip Joints ◽  
Four Point Bending ◽  
Pmma Bone Cement ◽  
Double Exponential

This paper describes tests that were carried out to model the stress relaxation behaviour of polymethylmethacrylate (PMMA) bone cement. Stress relaxation of bone cement is believed to be a significant factor in the mechanism of load transfer in the femoral stem of a polished, collarless taper-fit replacement hip joints. It is therefore important that this condition and its implications are understood. Stress relaxation was carried out on PMMA samples of varying age in four-point bending configuration. It was shown that the samples stiffened with age and that the amount of stress relaxation reduced as the samples aged. The experimental results of the stress relaxation were accurately modelled on the double exponential of the Maxwell model so that long-term predictions of the stress condition could be made from short-term mechanical tests.

EFFECT OF ANTIBIOTICS AUGMENTATION AND STORAGE CONDITION ON IMPACT RESISTANCE OF ORTHOPEDIC BONE CEMENT

2017 ◽  
Vol 17 (01) ◽  
pp. 1750019
Author(s):  
MARYAM KALANTARI ◽  
ATA HASHEMI
Keyword(s):  
Impact Strength ◽  
Bone Cement ◽  
Storage Temperature ◽  
Impact Resistance ◽  
Storage Condition ◽  
Four Point Bending ◽  
Pmma Bone Cement ◽  
Different Temperatures ◽  
Aging Conditions ◽  
The Impact

Antibiotic-impregnated poly(methyl methacrylate) (PMMA) bone cement has been successfully used to treat infected joint arthroplasties and surgeons have advocated the use of antibiotic-treated bone cement to prevent possible infections in joint replacement surgeries. However, there is a concern that this addition may adversely affect the mechanical properties of the bone cement. In most cases, the addition of antibiotics to bone cement has been reported to lower its mechanical strength. The uniaxial, biaxial and three/four point bending tests of antibiotic-impregnated bone cement have been extensively performed and well documented. However, only a few documents have focused on the impact strength of bone cement. The present study reports the impact tests of control and antibiotic loaded bone cements at different temperatures and aging conditions. According to the results, the addition of gentamicin or vancomycin significantly reduced the samples' impact strength. Moreover, the samples aged in saline at 23[Formula: see text]C were more resistant than the samples aged in air at 23[Formula: see text]C. Furthermore, raising the storage temperature from 23[Formula: see text]C to 37[Formula: see text]C significantly lowered the bone cement's impact strength in both control and antibiotic loaded samples.

scholarly journals Influence of HRGO Nanoplatelets on Behaviour and Processing of PMMA Bone Cement for Surgery

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2027
Author(s):  
Jaime Orellana ◽  
Ynés Yohana Pastor ◽  
Fernando Calle ◽  
José Ygnacio Pastor
Keyword(s):  
Graphene Oxide ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Reduced Graphene Oxide ◽  
Sintering Temperature ◽  
Structural Function ◽  
Mechanical And Thermal Properties ◽  
Poly Methyl Methacrylate ◽  
Pmma Bone Cement ◽  
Reduced Graphene

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients' surrounding tissues. To help avoid this problem, the addition of graphene could delay the polymerisation of the methyl methacrylate as it could, simultaneously, favour the optimisation of the composite material's properties. In this work, we address the effect of different percentages of highly reduced graphene oxide with different wt.% (0.10, 0.50, and 1.00) and surface densities (150, 300, 500, and 750 m2/g) on the physical, mechanical, and thermal properties of commercial poly (methyl methacrylate)-based bone cement and its processing. It was noted that a lower sintering temperature was achieved with this addition, making it less harmful to use in surgery and reducing its adverse effects. In contrast, the variation of the density of the materials did not introduce significant changes, which indicates that the addition of highly reduced graphene oxide would not significantly increase bone porosity. Lastly, the mechanical properties (strength, elastic modulus, and fracture toughness) were reduced by almost 20%. Nevertheless, their typical values are high enough that these new materials could still fulfil their structural function. In conclusion, this paper presents a way to control the sintering temperature, without significant degradation of the mechanical performance, by adding highly reduced graphene oxide so that local necrosis of bone cement based on poly (methyl methacrylate) used in surgery is avoided.

scholarly journals Developing of PMMA Bone Cement Performance by Modified TiO2NPs

2021 ◽  
Vol 1094 (1) ◽  
pp. 012150
Author(s):  
S K Al-Janabi ◽  
M H Al-Maamori ◽  
A J Braihi
Keyword(s):  
Bone Cement ◽  
Pmma Bone Cement

Development of Novel Bioactive PMMA-Based Bone Cement and its In Vitro and In Vivo Evaluation

2006 ◽  
Vol 309-311 ◽  
pp. 801-804 ◽  
Author(s):  
S.B. Cho ◽  
Akari Takeuchi ◽  
Ill Yong Kim ◽  
Sang Bae Kim ◽  
Chikara Ohtsuki ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Bone Cement ◽  
The Novel ◽  
In Vivo Evaluation ◽  
Natural Bone ◽  
Pmma Bone Cement ◽  
Rabbit Tibia

In order to overcome the disadvantage of commercialized PMMA bone cement, we have developed novel PMMA-based bone cement(7P3S) reinforced by 30 wt.% of bioactive CaO-SiO2 gel powders to induce the bioactivity as well as to increase mechanical property for the PMMA bone cement. The novel 7P3S bone cement hardened after mixing for about 7 minutes. For in vitro evaluation, apatite forming ability of it was investigated using SBF. When the novel 7P3S bone cement was soaked into SBF, it formed apatite on its surfaces within 1 week Furthermore; there is no decrease in its compressive strength within 9 weeks soaking in SBF. It is though that hardly decrease in compressive strength of 7P3S bone cement in SBF is due to the relative small amount of gel powder or its spherical shape and monosize. In vivo evaluation of the novel 7P3S bone cement was carried out using rabbit. After implantion into rabbit tibia for several periods, the interface between novel bone cement and natural bone was evaluated by CT images. According to the results, the novel bone cement directly contact to the natural bone without fibrous tissue after implantation for 4 weeks. This results indicates that the newly developed 7P3S bone cement can bond to the living bone and also be effectively used as bioactive bone cement without decrease in mechanical property.

The effect on the fatigue strength of bone cement of adding sodium fluoride

2001 ◽  
Vol 215 (2) ◽  
pp. 251-253 ◽  
Author(s):  
C Minari ◽  
M Baleanil ◽  
L Cristofolini ◽  
F Baruffaldi
Keyword(s):  
Fatigue Strength ◽  
Bone Cement ◽  
Sodium Fluoride ◽  
Biomedical Applications ◽  
Cement Mantle ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Bone Cements ◽  
The Novel ◽  
Pmma Bone Cement

New bone cements that include several additives are currently being investigated and tested. One such additive is sodium fluoride (NaF), which promotes bone formation, facilitating implant integration and success. The influence of NaF on the fatigue performance of the cement as used in biomedical applications was tested in this paper. In fact fatigue failure of the cement mantle is a major factor limiting the longevity of a cemented implant. An experimental bone cement with added NaF (12wt%) was investigated. The fatigue strength of the novel bone cement was evaluated in comparison with the cement without additives; fatigue tests were conducted according to current standards. The load levels were arranged based on a validated, statistically based optimization algorithm. The curve of stress against number of load cycles and the endurance limit were obtained and compared for both formulations. The results showed that the addition of NaF (12 wt %) to polymethylmethacrylate (PMMA) bone cement does not affect the fatigue resistance of the material. Sodium fluoride can safely be added to the bone cement without altering the fatigue performance of the PMMA bone cement.

Axisymmetric Finite Element Analysis of a Debonded Total Hip Stem With an Unsupported Distal Tip

1996 ◽  
Vol 118 (3) ◽  
pp. 399-404 ◽  
Author(s):  
T. L Norman ◽  
V. C. Saligrama ◽  
K. T. Hustosky ◽  
T. A. Gruen ◽  
J. D. Blaha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Relaxation ◽  
Bone Cement ◽  
Cement Mantle ◽  
Load Level ◽  
Interface Conditions ◽  
Element Analysis ◽  
Cement Interface ◽  
Total Hip

A tapered femoral total hip stem with a debonded stem-cement interface and an unsupported distal tip subjected to constant axial load was evaluated using two-dimensional (2D) axisymmetric finite element analysis. The analysis was performed to test if the mechanical condition suggest that a “taper-lock” with a debonded viscoelastic bone cement might be an alternative approach to cement fixation of stem type cemented hip prosthesis. Effect of stem-cement interface conditions (bonded, debonded with and without friction) and viscoelastic response (creep and relaxation) of acrylic bone cement on cement mantle stresses and axial displacement of the stem was also investigated. Stem debonding with friction increased maximum cement von Mises stress by approximately 50 percent when compared to the bonded stem. Of the stress components in the cement mantle, radial stresses were compressive and hoop stresses were tensile and were indicative of mechanical taper-lock. Cement mantle stress, creep and stress relaxation and stem displacement increased with increasing load level and with decreasing stem-cement interface friction. Stress relaxation occur predominately in tensile hoop stress and decreased from 1 to 46 percent over the conditions considered. Stem displacement due to cement mantle creep ranged from 614 μm to 1.3 μm in 24 hours depending upon interface conditions and load level.

scholarly journals Damage Evolution and Fracture Events Sequence Analysis of Core-Shell Nanoparticle Modified Bone Cements by Acoustic Emission Technique

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 208
Author(s):  
O.F. Pacheco-Salazar ◽  
Shuichi Wakayama ◽  
L.A. Can-Herrera ◽  
M.A.A. Dzul-Cervantes ◽  
C.R. Ríos-Soberanis ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Bone Cement ◽  
Solid Phase ◽  
Bending Test ◽  
Fracture Mechanisms ◽  
Core Shell ◽  
Bone Cements ◽  
Four Point Bending ◽  
Ae Signals ◽  
Cement Formulation

In this research, damage in bone cements that were prepared with core-shell nanoparticles was monitored during four-point bending tests through an analysis of acoustic emission (AE) signals. The core-shell structure consisted of poly(butyl acrylate) (PBA) as rubbery core and methyl methacrylate/styrene copolymer (P(MMA-co-St)) as a glassy shell. Furthermore, different core-shell ratios 20/80, 30/70, 40/60, and 50/50 were prepared and incorporated into the solid phase of the bone cement formulation at 5, 10, and 15 wt %, respectively. The incorporation of a rubbery phase into the bone cement formulation decreased the bending strength and bending modulus. The AE technique revealed that the nanoparticles play an important role on the fracture mechanism of the bone cement, since a higher amount of AE signals (higher amplitude and energy) were obtained from bone cements that were prepared with the nanoparticles in comparison with those without nanoparticles (the reference bone cement). The SEM examination of the fracture surfaces revealed that all of the bone cement formulations exhibited stress whitening, which arises from the development of crazes before the crack propagation. Finally, the use of the AE technique and the fracture surface analysis by SEM enabled insight into the fracture mechanisms that are presented during four-point bending test of the bone cement containing nanoparticles.

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