A Simulated Synovial Fluid for Wear Characterization of Artificial Hip Joints by a Hip Joint Simulator

2006 ◽  
Vol 309-311 ◽  
pp. 1273-1276 ◽  
Author(s):  
Hiroaki Takadama ◽  
Mineo Mizuno
Keyword(s):  
Hip Joint ◽  
Bovine Serum ◽  
Calf Serum ◽  
Major Constituent ◽  
Wear Property ◽  
Hip Joints ◽  
Artificial Hip ◽  
Artificial Hip Joints ◽  
Wear Characterization

The calf serum solution was defined as the international standard lubricant for wear characterization of artificial hip joints. It is, however, known that its composition varies according to age, manufacturing processes or production areas of bovine cattle, and that the difference in composition has large effect on the wear characterization. It was difficult to compare the results obtained by different laboratories. Therefore, it is desirable to develop an artificial lubricant whose composition can be always set to a specified value as an alternative to bovine serum. In the present study, the effect of each major constituent in bovine serum on wear property was studied by hip simulator. As a result, transparent and stable lubricant solutions were prepared. It showed quite similar wear property to bovine serum by controlling the composition. These results serve as a guide to propose the new lubricant suitable for the wear characterization of hip joint.

Alumina–alumina artificial hip joints. Part II: Characterisation of the wear debris from in vitro hip joint simulations

Biomaterials ◽  
2002 ◽  
Vol 23 (16) ◽  
pp. 3441-3448 ◽  
Author(s):  
J.L. Tipper ◽  
A. Hatton ◽  
J.E. Nevelos ◽  
E. Ingham ◽  
C. Doyle ◽  
...  
Keyword(s):  
Hip Joint ◽  
Wear Debris ◽  
Hip Joints ◽  
Artificial Hip ◽  
Artificial Hip Joints

Contact Mechanics of Soft Layer Artificial Hip Joints: Part 2: Application to Joint Design

1994 ◽  
Vol 208 (4) ◽  
pp. 206-215 ◽  
Author(s):  
J Q Yao ◽  
T V Parry ◽  
A Unsworth ◽  
J L Cunningham
Keyword(s):  
Shear Stress ◽  
Aspect Ratio ◽  
Coefficient Of Friction ◽  
Hip Joint ◽  
Contact Area ◽  
Hip Joints ◽  
Soft Layer ◽  
Physiological Loading ◽  
Artificial Hip ◽  
Artificial Hip Joints

In this paper, the general solutions previously obtained for the contact mechanics of a soft layer artificial hip joint have been applied to the design of such joints. In particular, simple power-law design formulae have been generated for the prediction of the contact radius and the maximum Tresca shear stress within the elastomeric layer, when the aspect ratio varied from 1 to 20 (which covered the entire range of the aspect ratio for soft layer artificial hip joints). The effects of the layer thickness, Young's modulus of the layer and the equivalent radius of the joint upon the contact area and the maximum Tresca shear stress have all been examined for physiological loading conditions which would be experienced by hip joint prostheses in the body. Furthermore, the shear strain field was calculated so that the level of strain expected for such joints under physiological loading conditions can be estimated. With these data, relevant fatigue tests can be devised to assess the long-term performance of any particular design of soft layer hip joint. Finally, the effect of the friction between articular surfaces upon the stress field within soft layers has been examined using a newly developed asymptotic analytical theory. It was shown that, for a low coefficient of friction, the maximum Tresca shear stress occurred at layer-substrate bonding interface. With an increase in the coefficient of friction, however, the maximum Tresca shear stress increased its magnitude and moved towards the centre of the contact area along the articular surface.

scholarly journals Measurement and evaluation of specific absorption rate and temperature elevation caused by an artificial hip joint during MRI scanning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Youngseob Seo ◽  
Zhiyue J. Wang
Keyword(s):  
High Temperature ◽  
Hip Joint ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Rf Heating ◽  
Temperature Elevation ◽  
Hip Joints ◽  
Specific Absorption ◽  
Artificial Hip ◽  
Artificial Hip Joints

AbstractA primary safety concern in a magnetic resonance imaging environment is heating of metallic implants by absorbing radiofrequency (RF) energy during MRI scanning. Experimental measurement in conjunction with computational modeling was used to evaluate the risk of biological tissue injury from the RF heating of artificial hip joints by obtaining both specific absorption rate (SAR) and temperature elevation at 1.5 T and 3 T MRI systems. Simulation result showed that high SAR and high temperature appeared near both head and tail sections of the artificial hip joints. For five different 1.5 T and 3 T MRI systems, measured temperature location showed that high temperature rises occurred near both head and tail regions of the metallic hip joints. Measured SAR value of 24.6 W/kg and the high temperature rise (= 4.22 °C) occurred in the tail region of the hip joint at 1.5 T, which was higher than the limits for temperature required by the international electrotechnical commission 60601-2-33. We have demonstrated the feasibility of evaluating RF heating of metallic hip joints during MRI scans.

Elasto-Hydrodynamic Lubrication Modelling of Spherical Metal-on-Metal Artificial Hip Joints

2005 ◽  
Author(s):  
F. C. Wang ◽  
Z. M. Jin ◽  
I. J. Udofia
Keyword(s):  
Hip Joint ◽  
Hydrodynamic Lubrication ◽  
Hip Joints ◽  
Hip Implant ◽  
Metal On Metal ◽  
Artificial Hip ◽  
Joint Implants ◽  
Artificial Hip Joints

A full numerical methodology was developed for the elasto-hydrodynamic lubrication analysis of hip joint implants for the lubrication problem in spherical and conformal contacts. Typical results of a metal-on-metal hip implant were obtained to illustrate the applicability of the numerical methodology developed in the present study.

The influence of phospholipid concentration in protein-containing lubricants on the wear of ultra-high molecular weight polyethylene in artificial hip joints

2001 ◽  
Vol 215 (2) ◽  
pp. 259-263 ◽  
Author(s):  
J Bell ◽  
J L Tipper ◽  
E Ingham ◽  
M H Stone ◽  
J Fisher
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Phosphatidyl Choline ◽  
Bovine Serum ◽  
Hip Joints ◽  
Wear Rates ◽  
Artificial Hip ◽  
Artificial Hip Joints ◽  
Ultra High Molecular Weight

There is considerable interest in the wear of polyethylene and the resulting wear-debrisinduced osteolysis in artificial hip joints. Proteins play an important role as boundary lubricants in vivo in the pseudosynovial fluid, and these are reproduced in in vitro tests through the use of bovine serum. Little is known, however, about the effect of phospholipid concentrations within proteinaceous solutions on the wear of ultra-high molecular weight polyethylene (UHMWPE). The effects of protein-containing lubricants with 0.05, 0.5 and 5 per cent (w/v) phosphatidyl choline concentrations on the wear of ultra-high molecular weight polyethylene (UHMWPE) were compared with 25 per cent (v/v) bovine serum which had 0.01 per cent (w/v) lipid; the effects were compared in a hip joint simulator with smooth (n = 4) and scratched (n = 3) femoral heads. The control bovine serum lubricant produced UHWMPE wear of 55 and 115mm3/106 cycles on the smooth and rough heads respectively. The increased phospholipid concentration significantly reduced the wear rate. At the higher concentration (5% w/v phosphatidyl choline) the average wear was reduced to less than 2 mm3/106 cycles. Even with the relatively low concentrations of 0.05% w/v phosphatidyl choline the wear was reduced by at least threefold compared with the bovine serum tests for both the smooth and rough femoral heads. There may be considerable differences in the phospholipid concentrations in patients' synovial fluid and this is highly likely to produce considerable variation in wear rates. In vitro, differences in the phospholipid concentration of lubricants may also cause variation in wear rates between different simulator tests.

Metal-On-Metal Articulation for Artificial Hip Joints: Laboratory Study and Clinical Results

1996 ◽  
Vol 210 (3) ◽  
pp. 223-232 ◽  
Author(s):  
R M Streicher ◽  
M Semlitsch ◽  
R Schön ◽  
H Weber ◽  
C Rieker
Keyword(s):  
Hip Joint ◽  
Laboratory Data ◽  
Clinical Results ◽  
Hip Joints ◽  
Wear Rates ◽  
Metal On Metal ◽  
Artificial Hip ◽  
Artificial Joint Replacement ◽  
Artificial Hip Joints ◽  
Screening Device

As wear is inevitable with artificial joint replacement, it has to be minimized to avoid possible aseptic loosening following osteolysis due to particle-initiated foreign body reaction. Co-Cr-Mo-C alloys have a long history with only minimum wear when articulating with themselves. This investigation shows that the choice of the alloy has an effect on the wear rate of this articulation couple. Tribological studies in a screening device, a pendulum apparatus and a hip joint simulator showed a marked influence of the environment as well as the diameter of the implants with metal-on-metal articulation. A wear-resistant combination with low friction characteristics has been developed by using a wrought Co-Cr-Mo-C alloy and reducing the implant diameter to 28 mm. Clinical wear rates are comparable with laboratory data and demonstrate the potential of the metal-on-metal articulation to solve the problem of wear-induced osteolysis of hip joint endoprostheses.

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