Computer Assisted Femoral Augmentation: Modeling and Experimental Validation

2013 ◽  
Author(s):  
Ehsan Basafa ◽  
Ryan J. Murphy ◽  
Michael D. Kutzer ◽  
Yoshito Otake ◽  
Mehran Armand
Keyword(s):  
Mechanical Properties ◽  
Bone Cement ◽  
Experimental Validation ◽  
Particle Method ◽  
Computer Assisted ◽  
Injection Device ◽  
Pmma Bone Cement ◽  
Ct Data ◽  
Scan Data ◽  
The One

We report the results of planning and experimental validation of femoroplasty — augmentation of mechanical properties of the bone using polymethylmethacrylate (PMMA) bone cement injection — on osteoporotic femurs. For six pairs of osteoporotic femurs, finite element (FE) models were created using computed tomography (CT) scan data and an evolutionary method was used to optimize the cement pattern in one of the models from each pair. Using a particle method and the CT data, cement diffusion was modeled for several hypothetical augmentations and the one most closely matching the optimized pattern was chosen as the best plan. We used intra-operative navigation and a custom-designed injection device to deliver the cement into the bones precisely according to the plan. All femurs were then tested mechanically in a configuration simulating a fall to the side. Augmentation with this technique resulted in an increase in the yield load (28%) and yield energy (142%) compared to the control specimens, while only 9.8ml of cement was injected on average. Results support our hypothesis that significant improvements in the mechanical properties of osteoporotic femurs can be achieved by using minimal, and hence safe, amounts of PMMA bone cement.

Influence of Antibiotics Addition in Bone Cements for Hip Arthroplasty on their Mechanical Properties: Clinical Perspective and In Vitro Tests

2016 ◽  
Vol 695 ◽  
pp. 123-127
Author(s):  
Razvan Ene ◽  
Zsombor Panti ◽  
Mihai Nica ◽  
Marian Pleniceanu ◽  
Patricia Ene ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Cement ◽  
Hip Arthroplasty ◽  
Revision Surgery ◽  
Bone Cements ◽  
Artificial Joints ◽  
The One ◽  
Prophylactic Method ◽  
Active Substances

Bone cement has been used for over half a century, to successfully anchor artificial joints. From its emergence there have appeared a number of types of bone cement, with the 2 major classes being bone cement with or without active substances. The one with the added antibiotics is used primarily in the treatment and revision surgery of infected total hip arthroplasty (THA), as well as a prophylactic method in primary THA in patients with high risks for this complication. The purpose of this study is to determine the mechanical properties of bone cement with added antibiotics. Over a period of 2 years, a number of 41 cases were chosen for this study: 25 with revision surgery for THA, where bone cement with antibiotics was used, and 16 with primary THA, where regular bone cement was used. A number of studies have been performed on the mechanical properties of the 2 types of cement, which determined that the cement with antibiotics presents a slightly lower compressive strength, tensile strength, elastic modulus and fatigue strength compared with regular cement. These variations, however, become more pronounced as the quantity of the antibiotic goes up. The mechanical properties of the cement with antibiotics are similar with those of the regular cement, when low doses of antibiotics are used and become more evident as the doses go up. In conclusion, the antibiotic bone cement is a trustworthy tool in the surgeon’s arsenal against infection, with minimal detriments from the mechanical view.

scholarly journals Modification of Mechanical Properties, Polymerization Temperature, and Handling Time of Polymethylmethacrylate Cement for Enhancing Applicability in Vertebroplasty

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ching-Lung Tai ◽  
Po-Liang Lai ◽  
Wei-De Lin ◽  
Tsung-Tin Tsai ◽  
Yen-Chen Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Cement ◽  
Castor Oil ◽  
Oil Content ◽  
Handling Time ◽  
Polymerization Temperature ◽  
Preparation Temperature ◽  
Maximum Compression ◽  
Pmma Bone Cement ◽  
Low Modulus

Polymethylmethacrylate (PMMA) bone cement is a popular bone void filler for vertebroplasty. However, the use of PMMA has some drawbacks, including the material’s excessive stiffness, exothermic polymerization, and short handling time. This study aimed to create an ideal modified bone cement to solve the above-mentioned problems. Modified bone cements were prepared by combining PMMA with three different volume fractions of castor oil (5%, 10%, and 15%). The peak polymerization temperatures, times to achieve the peak polymerization temperature, porosities, densities, modulus and maximum compression strengths of standard (without castor oil), and modified cements were investigated following storage at ambient temperature (22°C) or under precooling conditions (3°C). Six specimens were tested in each group of the aforementioned parameters. Increasing castor oil content and precooling treatment effectively decreased the peak polymerization temperatures and increased the duration to achieve the peak polymerization temperature (P<0.05). Furthermore, the mechanical properties of the material, including density, modulus, and maximum compression strength, decreased with increasing castor oil content. However, preparation temperature (room temperature versus precooling) had no significant effect (P>0.05) on these mechanical properties. In conclusion, the addition of castor oil to PMMA followed by precooling created an ideal modified bone cement with a low modulus, low polymerization temperature, and long handling time, enhancing its applicability and safety for vertebroplasty.

Structure of the metallurgically oriented modelling system TK-StripCam for simulation of hot strip manufacture and application in research and production practice

2004 ◽  
Vol 120 ◽  
pp. 801-808
Author(s):  
U. Lotter ◽  
H.-P. Schmitz ◽  
L. Zhang
Keyword(s):  
Mechanical Properties ◽  
Simulation System ◽  
Physical Models ◽  
Computer Assisted ◽  
Microstructural Parameters ◽  
Hot Strip ◽  
Production Practice ◽  
Prediction Of Mechanical Properties ◽  
The One ◽  
Kinetics Of

For the prediction of mechanical properties of hot strip from production conditions by metallurgically oriented computer assisted simulation it is necessary to model all the numerous metallurgical processes leading to the microstructure of the finished product. The relevant microstructural parameters, calculated in this way, finally are converted into mechanical properties by application of suitable algorithms. At ThyssenKrupp Stahl such a metallurgically oriented simulation system has been developed and established under the name TK-StripCam. It is based on empirical-physical models. It allows on the one hand to predict important mechanical properties with considerable precision from production parameters as rolling schedule, cooling conditions etc. On the other hand by means of the simulation system course and kinetics of each metallurgical process included may be studied. It is evident that in a steel plant such a powerful tool finds a great variety of applications extending from offline use as a tool for development of steels and processes to inline use in the rolling mill to control the mechanical properties during production. In this work details of the philosophy and structure of the simulation system and examples for its application are presented.

Nanosilver-loaded PMMA bone cement doped with different bioactive glasses – evaluation of cytocompatibility, antibacterial activity, and mechanical properties

2021 ◽  
Vol 9 (8) ◽  
pp. 3112-3126
Author(s):  
M. Wekwejt ◽  
S. Chen ◽  
B. Kaczmarek-Szczepańska ◽  
M. Nadolska ◽  
K. Łukowicz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Bone Cement ◽  
Bioactive Glasses ◽  
Pmma Bone Cement

Nanosilver-loaded PMMA bone cement doped with bioactive glasses is a novel cement developed as a replacement for conventional cements.

Bioactive PMMA-Based Cement Incorporated with Nano-Sized Rutile Particles

2006 ◽  
Vol 309-311 ◽  
pp. 797-800 ◽  
Author(s):  
Masami Hashimoto ◽  
Hiroaki Takadama ◽  
Mineo Mizuno ◽  
Tadashi Kokubo ◽  
Koji Goto ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Simulated Body Fluid ◽  
Mechanical Strength ◽  
Bone Cement ◽  
Body Fluid ◽  
Bone Substitutes ◽  
Hardened Cement ◽  
Pmma Bone Cement

Bioactive bone cement with mechanical properties higher than that of commercial polymethylmethacrylate (PMMA) bone cement are strongly desired to be developed. In the present study, PMMA-based cement incorporated with nano-sized rutile particles was prepared. The PMMA-based cement (rutile content was 50 wt%) shows the compressive strength (136 MPa) higher than that of commercial PMMA bone cement (88 MPa). The hardened cement formed apatite on the surface in a simulated body fluid within 3 days. Therefore, this PMMA-based cement incorporated with rutile particles might be useful as cement for fixation of prostheses as well as self-setting bone substitutes, because of its high apatite forming ability and mechanical strength.

A Study of Mechanical Properties of Bone Cement Containing Micro- and Nano- Hydroxyapatite Particles

2018 ◽  
Vol 766 ◽  
pp. 117-121
Author(s):  
Phanrawee Sriprapha ◽  
Chaiy Rungsiyakull ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri ◽  
Sukum Eitssayeam
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bone Cement ◽  
Hot Water ◽  
Cylindrical Shape ◽  
Bovine Bone ◽  
Steel Mold ◽  
Micro Particles ◽  
Porosity Reduction ◽  
Pmma Bone Cement

In this research, mechanical properties of bone cement containing micro-and nanohydroxyapatite (HAp) particles were studied. The bone cement was prepared from mixing between polymethyl methacrylate (PMMA) and methyl methacrylate (MMA). Hydroxyapatite powder was prepared from bovine bone. The bone was heated in hot water at 200 oc for the elimination of tissue, after which the bone was dried and calcined at 800 oc for 3 hrs. The calcined bone than was crushed into powder and ball-milled for 24 hrs. The micro-HAp particle was then obtained. The micro particles were then further milled employing the Vibro-milling machine for 2 hrs. The micro-and nanoHAp sizes are about 0.5 μm and 140 nm, respectively. The both size powders were treated with γ-methacrylic-propyl-tri-methoxy silane. The acetic acid was added to control the pH of the solution, until it reached 2.9 before they were mixed into the bone cement with equally wt%. The mixture was casted using the 304 stainless steel mold in order to obtain a cylindrical shape. The low vacuum scanning electron microscope (LV-SEM) and x-ray diffractometer (XRD) were employed to characterize the samples. The porosity of PMMA could be reduced by HAp particle additives. From compressive strength test, it was found that the mixture of bone cement and nanoHAp particle has shown higher compressive strength than pure PMMA bone cement that affected by porosity reduction and force distribution by HAp particles.

An Investigation into the Effect of Cyclic Loading and Frequency on the Temperature of Pmma Bone Cement in Hip Prostheses

1989 ◽  
Vol 203 (3) ◽  
pp. 167-170 ◽  
Author(s):  
P K Humphreys ◽  
J F Orr ◽  
A S Bahrani
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Cyclic Loading ◽  
Bone Cement ◽  
Temperature Rise ◽  
Hip Prosthesis ◽  
Temperature Measurements ◽  
Hip Prostheses ◽  
Pmma Bone Cement

A titanium alloy hip prosthesis was inserted in a Tufnol tube representing the upper part of the femur. The prosthesis was cemented in the model femur using PMMA bone cement. Five thermocouples were embedded in the bone cement and the assembly was subjected to cyclic loading with a range of 0.3–4.5 kN at a frequency of 6 Hz. Temperature measurements over a 48 hour period indicated that the temperature rise in the bone cement was less than 4°C. It is concluded that such tests can be carried out at 6 Hz without significantly affecting the mechanical properties of PMMA bone cement.

An Automatic Injection Device for Precise Cement Delivery During Osteoporotic Bone Augmentation

2011 ◽  
Author(s):  
Michael D. Kutzer ◽  
Ehsan Basafa ◽  
Yoshito Otake ◽  
Mehran Armand
Keyword(s):  
Bone Cement ◽  
Ease Of Use ◽  
Design Parameters ◽  
Osteoporotic Bone ◽  
Injection Device ◽  
High Injection ◽  
Pmma Bone Cement ◽  
Automatic Placement ◽  
Set Up ◽  
Injection Rates

Augmentation of osteoporotic bone with polymethylmethacrylate (PMMA) bone cement has been shown to be effective in reducing the risk of bone fracture. Injection of the highly viscous bone cement, however, is challenging mainly due to high injection forces required to maintain the nominal injection rates. Also, effective placement of the cement requires precise planning and execution. We are developing a surgical workstation for planning and executing proximal femur augmentation. As a crucial part of the framework, we have designed and fabricated a prototype automatic injection device that provides the substantial forces while maintaining the planned injection rates. Design parameters were determined based on the criteria available in the literature and our preliminary tests. Intended features for the device included high injection force capability, precisely controllable injection and ease of use. A number of calibration experiments were performed to ensure that the device meets the intended criteria. The device can be quickly set up before the surgical operation and can operate in manual or automatic placement configurations. The automatic injection device can also be used for a range of other orthopaedic applications involving direct augmentation of the bones or screws fixated in the bones.

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