Creep Testing of a Composite Material Human Hip Prosthesis

2009 ◽  
pp. 86-86-12 ◽  
Author(s):  
GR Maharaj ◽  
RD Jamison
Keyword(s):  
Composite Material ◽  
Hip Prosthesis ◽  
Creep Testing

An Isoelastic Prosthesis Using a New Composite Material

1993 ◽  
Vol 207 (2) ◽  
pp. 121-125 ◽  
Author(s):  
D Taylor ◽  
C Martin ◽  
B Cornelis ◽  
M E B Jones
Keyword(s):  
Composite Material ◽  
Stress Analysis ◽  
Hip Prosthesis ◽  
Fibre Composite ◽  
Testing Machine ◽  
Proximal Region ◽  
Critical Crack ◽  
Critical Crack Length ◽  
Moulding Process ◽  
Transfer Moulding

A new particulate composite material has been assessed with regard to the design of an ‘isoelastic’ or ‘modulus matched’ hip prosthesis. Three different prototype designs were assessed, each of which consisted of a femoral component made from the composite material, attached to a metal ball via a metal ‘spike’ insert. The prototypes varied in terms of the detailed shape of the spike, which was modified in the light of photoelastic stress analysis, so as to produce a more acceptable stress distribution to the composite material in the proximal region. Prototypes were made by hand moulding and by transfer moulding; both methods produced defects of various kinds. Simulation tests were conducted using a model of the proximal femur constructed from glass fibre composite, cyclically loaded in a servo-hydraulic testing machine. Though some difficulties were experienced with defective mouldings, especially for the transfer moulding process, a clear improvement was demonstrated for the final (Mark III) design. The fatigue endurance of this prototype was similar to that of conventional metal prostheses tested under similar conditions. Fatigue crack propagation tests were carried out on samples of the composite material to establish its propagation threshold. These results were combined with a finite element stress analysis and fracture mechanics theory to estimate the critical crack length for fatigue in this prosthesis. It was thus possible to specify the maximum safe size of defect that could be tolerated in use.

Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

1991 ◽  
Vol 49 ◽  
pp. 34-35 ◽  
Author(s):  
P. Frayssinet ◽  
J. Hanker ◽  
D. Hardy ◽  
B. Giammara
Keyword(s):  
Hip Prosthesis ◽  
Ethanol Concentration ◽  
Bone Matrix ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Hip Prostheses ◽  
Cellular Inclusions ◽  
Microscopic Studies ◽  
Diamond Saw ◽  
Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

Atomic structure of interface of intermetallic compound TiAl and nitride Ti2AIN using HREM and image processing

1991 ◽  
Vol 49 ◽  
pp. 570-571
Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama
Keyword(s):  
Mechanical Properties ◽  
Image Processing ◽  
Composite Material ◽  
Intermetallic Compound ◽  
Side Surface ◽  
High Resolution Electron Microscopy ◽  
Hexagonal Structure ◽  
Second Phase ◽  
Resolution Electron ◽  
Compound Tial

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.

The microstructure of a TiB2/Ti-47 Al composite material

1989 ◽  
Vol 47 ◽  
pp. 674-675
Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz
Keyword(s):  
Composite Material ◽  
Ion Beam ◽  
Chemical Properties ◽  
Intermetallic Alloys ◽  
Transmission Electron ◽  
Diamond Polishing ◽  
Al Composite ◽  
The Matrix ◽  
Argon Ion ◽  
And Chemical Properties

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.

Femoral-shaft fracture below hip prosthesis

JAMA ◽  
1965 ◽  
Vol 194 (13) ◽  
pp. 1378-1381
Author(s):  
O. E. Aufranc
Keyword(s):  
Femoral Shaft Fracture ◽  
Hip Prosthesis ◽  
Femoral Shaft ◽  
Shaft Fracture

Analysis of 18F-FDG uptake patterns in PET for diagnosis of septic and aseptic loosening after total hip arthroplasty

2003 ◽  
Vol 42 (06) ◽  
pp. 234-239 ◽  
Author(s):  
T. Mumme ◽  
P. Reinartz ◽  
D. Wirtz ◽  
F. U. Niethard ◽  
U. Büll ◽  
...  
Keyword(s):  
Aseptic Loosening ◽  
Femoral Component ◽  
Hip Prosthesis ◽  
Prosthetic Infection ◽  
Clinical Value ◽  
Septic Loosening ◽  
Hip Prostheses ◽  
Fdg Uptake ◽  
Positron Emission ◽  
Painful Hip

Summary Aim: Identification of typical patterns for fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) to detect aseptic loosening of hip prosthesis (ace-tabular and/or femoral component) and prosthetic infection. Methods: 18 patients with painful hip prosthesis underwent PET using a dedicated full ring scanner after application of 200-300 MBq FDG. The interface between bone and surrounding soft tissue or bone as displayed on coronal slices was divided into 12 segments in accordance with the classifications of Delee and Gruen. FDG uptake in each of the segments was scored (0-3) by two independent observers. Intraoperative findings were regarded as the gold standard. Results: After surgical revision 14 acetabular components and 9 femoral components were found to be loose and prosthetic infection was present in 7 prostheses. Loosening of the acetabular component was correlated to enhanced uptake in the middle of the acetabular interface, while loosening of the femoral component was correlated to enhanced uptake in the proximal and middle segment of the lateral femoral interface and the proximal segment of the medial femoral interface. A similar pattern was found in prosthetic infection with high uptake along the middle portion of the lateral fe-moral interface. In 6 of 7 infected prostheses loosening of the acetabular and of the femoral component was present. Taking the typical uptake patterns as criteria for loosening and grade 3 uptake as an additional criterion for septic loosening the accuracy of PET imaging in the detection of loosening of the acetabular or the femoral component and of prosthetic infection was 72, 78 and 89%, respectively. Conclusion: This pilot study presents FDG-PET as a promising diagnostic tool for patients with painful hip prostheses. Its clinical value should be evaluated in a larger patient population.

Plasma Prekallikrein Activity in Patients with Total Hip Arthroplasty

1987 ◽  
Vol 58 (04) ◽  
pp. 1040-1042
Author(s):  
J J M L Hoffmann ◽  
J H J P M Kortmann
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Hip Prosthesis ◽  
Contact System ◽  
Factor Xii ◽  
Total Hip ◽  
Activity Factor ◽  
Patient Groups ◽  
Kallikrein Activity

SummaryThe behaviour of the contact system was studied in 40 patients with total hip arthroplasty, by measuring plasma prekallikrein, spontaneous kallikrein activity and factor XII. In the literature it had been shown that patients with complications from this operation had decreased prekallikrein and increased kallikrein activity (M. Nakahara. Acta orthop scand 1982; 53: 591-6). In the present study, comprising patients with and without pain and proven loosening of the hip prosthesis, these findings could only partially be confirmed. Patients with a loosened prosthesis had significantly lower prekallikrein (mean 0.78 ± 0.28 U/ml; p <0.01) than patients without problems, but no detectable kallikrein activity in plasma. Patients with pain but no loosening had normal prekallikrein (1.04 ±0 0.26 U/ml) and also no demonstrable kallikrein activity. Factor XII was normal in all patient groups. It is concluded that decreased prekallikrein is limited to patients with a loosened hip prosthesis, with or without pain.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

A method for determining the natural moisture content of dentin in a clinical setting

2020 ◽  
Vol 1 (12) ◽  
pp. 36-39
Author(s):  
L. V. Iyashvili ◽  
Yu. A. Vinnichenko ◽  
A. V. Vinnichenko
Keyword(s):  
Composite Material ◽  
Moisture Content ◽  
Computer Program ◽  
Clinical Setting ◽  
Quantitative Assessment ◽  
Critical Mass ◽  
Filling Material ◽  
Adhesive Interaction ◽  
Natural Moisture Content ◽  
Hard Tissues

The purpose of the study is a quantitative assessment of the yield of dentinal fluid on the surface of the treated dentin of the tooth when restoring its structure with a composite filling material. To achieve this goal, digital images of the coronal parts of the teeth having formed carious cavities were used; virtual models of hard tissues of teeth recreated using specialized computer programs; A computer program that provides the ability to accurately determine the area of the treated dentin tooth. The results made it possible to draw the following conclusions: with an increase in the depth of the carious cavity, the amount of dentin fluid that can stand out on its surface (1–2 mm from the tooth cavity) sharply increases; with an increase in the area of the formed carious cavity (more than 30 mm2), the risk of release of a critical mass of dentinal fluid (more than 0.4 mg), which can adversely affect the strength of the adhesive interaction between the composite material and the hard tissues of the tooth, increases significantly; the same dynamics is observed with increasing time, at which there is the possibility of free exit of dentinal fluid to the surface of the cavity prepared for filling (more than 45 seconds).

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