A Five-Station Hip Joint Simulator for Wear Rate Studies

1992 ◽  
Vol 206 (4) ◽  
pp. 195-200 ◽  
Author(s):  
V Saikko ◽  
P Paavolainen ◽  
M Kleimola ◽  
P Slätis
Keyword(s):  
Wear Rate ◽  
Hip Joint ◽  
Original Position ◽  
Total Hip ◽  
Joint Contact Force ◽  
Long Duration ◽  
Environment Temperature ◽  
Flexion Extension ◽  
Joint Contact ◽  
Hip Joint Simulator

The aim of the work has been the development of a hip joint simulator for comparative wear rate studies of long duration. A five-station apparatus has been designed, constructed and tested. Five total hip joints can be tested at the same time in identical conditions. The flexion-extension motion and the superior-inferior component of the joint contact force are incorporated. The motion is electromechanical and the loading pneumatic. The angle and load waveforms are fixed and simulate level walking. For accurate wear measurements each station employs a control prosthesis. The conditions of the control prosthesis in regard to loading, exposure to lubricant and environment temperature (37 ± 1°C) are identical to those of the test prosthesis. The acetabular cups can be readily removed for periodic wear measurements and reassembled in exactly the original position. Extensive tests have shown that the simulator is a practical and reliable instrument in the wear rate studies of various designs of total hip joint.

A Three-Axis Hip Joint Simulator for Wear and Friction Studies on Total Hip Prostheses

1996 ◽  
Vol 210 (3) ◽  
pp. 175-185 ◽  
Author(s):  
Vesa O Saikko
Keyword(s):  
Hip Joint ◽  
External Rotation ◽  
Frictional Torque ◽  
Hip Prostheses ◽  
Total Hip ◽  
Flexion Extension ◽  
Single Station ◽  
Wear And Friction ◽  
Total Hip Prostheses ◽  
Hip Joint Simulator

A three-axial, single-station hip joint simulator was designed and built for wear and friction studies on total hip prostheses. The design of the apparatus is described in detail. Continuous level walking is simulated. All three motion components, flexion-extension, abduction-adduction and internal-external rotation, are included. The motions are implemented electromechanically and the uniaxial load pneumatically. The load is measured continuously. For accurate measurement of wear, the apparatus has a loaded control joint, which also renders both the test and control joints self-centring, as they are loaded in series. The frictional torque of the test joint can be measured continuously throughout the wear test, which is an exceptional feature. Four tests of five million cycles each were completed using 32 mm diameter Co-Cr-Mo femoral heads and 5.6 mm thick, metal-backed, ultra-high molecular weight polyethylene acetabular cups as test specimens. Their wear and friction behaviour is described and discussed in relation to previous simulator studies and clinical observations. The lubricant was distilled water, maintained at body temperature. The wear of the cups was measured gravimetrically at intervals. The average wear rate was 3.9 mg/one million cycles, corresponding to 0.03 mm/year, and the average coefficient of friction was 0.01.

scholarly journals Evaluation of the hip joint contact force in subjects with Perthes based on OpenSIM

2019 ◽  
Vol 67 ◽  
pp. 44-48
Author(s):  
Mohammad Taghi Karimi ◽  
Lanie Gutierrez-Farewik ◽  
Anthony McGarry
Keyword(s):  
Contact Force ◽  
Hip Joint ◽  
Joint Contact Force ◽  
Joint Contact ◽  
Hip Joint Contact Force

Computational modelling of polyethylene wear and creep in total hip joint replacements: Effect of the bearing clearance and diameter

2012 ◽  
Vol 226 (6) ◽  
pp. 552-563 ◽  
Author(s):  
Feng Liu ◽  
John Fisher ◽  
Zhongmin Jin
Keyword(s):  
Wear Rate ◽  
Hip Joint ◽  
Contact Area ◽  
Polyethylene Wear ◽  
Computational Modelling ◽  
Total Hip ◽  
Bearing Clearance ◽  
Wear Modelling ◽  
Wear Law ◽  
Hip Joint Replacements

Computational wear modelling has been improved using a contact area dependent wear law for the conventional ultra-high molecular weight polyethylene used in total hip joint bearings. The current designs of polyethylene bearings tend to use larger diameter heads to achieve improved motion function for patients in clinical practice, but the wear of the bearing may also increase due to the increase in contact area associated with the larger bearings. Additionally, bearing clearance, which is the difference in diameter or radius between the cup and head bearing surfaces, may also play an important role in affecting the wear. This study particularly investigates the effect of bearing clearance on polyethylene wear, for different femoral head diameters, through a parametric study using the computational modelling method. The effect of creep of polyethylene on the contact area and wear was considered, since polyethylene creep can account for a significantly large proportion of volumetric change, particularly during the initial loading stage, and an increase in the contact area. The predicted wear rate was found to be comparable to the experimental wear rate found in independent simulator tests. The polyethylene bearing with decreased bearing clearances led to a substantial increase in the wear rate, particularly when combined with large diameters.

Workspace analysis of 3SPS+1PS bionic parallel test platform for hip joint simulator

2011 ◽  
Vol 225 (9) ◽  
pp. 2216-2231 ◽  
Author(s):  
G Cheng ◽  
J-L Yu ◽  
S-R Ge ◽  
S Zhang
Keyword(s):  
Hip Joint ◽  
Parallel Manipulator ◽  
Jacobi Matrix ◽  
Parallel Test ◽  
Flexion Extension ◽  
Test Platform ◽  
Moving Platform ◽  
Joint Prostheses ◽  
Hip Joint Simulator ◽  
Orientation Workspace

In order to evaluate the movement performance of a human hip joint, a novel parallel manipulator called 3SPS+1PS bionic parallel test platform is proposed in this article. SPS denotes the spherical-prismatic-spherical leg, and PS the prismatic-spherical leg where only the prismatic joint is actuated and hence underlined. For the 3SPS+1PS bionic parallel test platform with four degrees of freedom including three rotations and one translation, the formulae for solving the inverse kinematics equations are derived based on the quaternion method. Unit quaternion is used to represent the position and orientation of a moving platform, and singularities caused by Euler angles are avoided. Combining the topological structure characteristics of the parallel manipulator, the orientation workspace of the moving platform at a given translation position is constructed. Moreover, the procedures to solve and evaluate the orientation workspace of the parallel manipulator are obtained. In order to ensure dexterity and obtain more workspace, the condition index is studied by the condition number and singular values analysis of the dimensionally homogeneous Jacobi matrix. The parallel manipulator has three rotations about the Z-axis, the Y-axis, and the X-axis applied to represent three rotation motions (flexion/extension (FE), abduction/adduction (AA), and internal/external (IE) rotation motion) of a human hip joint, respectively. The numerical results illustrate that the 3SPS + 1PS bionic parallel test platform generates ±25° to ±108° in FE, −20° to 20° in AA, and −21° to 21° in IE rotation where the maximum permissible condition numbers of Jacobi matrix are set within the range 15–20 and the parallel manipulator can provide full-scale friction motion for hip joint simulator. In the dexterous orientation workspace, the slide track on the friction counterface of hip joint prostheses can be varied consistently. By verifying the lengths of the SPS-type active legs, the parallel manipulator can provide cross-path multidirectional slide motion for hip joint prostheses. The three-dimensional model and kinematics simulation of the manipulator are established and analysed. The simulation results prove that the 3SPS + 1PS bionic parallel test platform can accurately represent human hip joint motion and provide more reliable experimental data for hip joint prostheses in clinical application. The research builds the theoretical basis for its bionic motion simulation in practical application.

scholarly journals In Vitro Analysis of Wearing of Hip Joint Prostheses Composed of Different Contact Materials

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3805
Author(s):  
Jian Su ◽  
Jian-Jun Wang ◽  
Shi-Tong Yan ◽  
Min Zhang ◽  
Hui-Zhi Wang ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Vitamin E ◽  
Femoral Head ◽  
Wear Rate ◽  
Hip Joint ◽  
Cobalt Chromium ◽  
Significant Difference ◽  
Joint Prostheses ◽  
Hip Joint Simulator

Cobalt-chromium-molybdenum alloy (CoCrMo) and ceramic are the two most common materials for the femoral head in hip joint prostheses, and the acetabular liner is typically made from ultra-high molecular weight polyethylene (UHMWPE), highly cross-linked polyethylene (XLPE), or highly cross-linked polyethylene blended with Vitamin E (VEXLPE). The selection of suitable materials should consider both wear performance and cost-effectiveness. This study compared the wear rate between different friction pairs using a hip joint simulator and then recommended a suitable prosthesis based on the corresponding processing technology and cost. All wear simulations were performed in accordance with ISO 14242, using the same hip joint simulator and same test conditions. This study found that when using the same material for the femoral head, the XLPE and VEXLPE liners had a lower wear rate than the UHMWPE liners, and the wear rate of the XLPE liners increased after blending with Vitamin E (VEXLPE). There was no significant difference in the wear rate of XLPE when using a CoCrMo or ceramic head. Considering the wear rate and cost-effectiveness, a CoCrMo femoral head with an accompanying XLPE liner is recommended as the more suitable combination for hip prostheses.

scholarly journals Positive Correlation Between the Hip Adduction Moment Impulse During the Stance Phase and the Hip Joint Contact Force Impulse

2020 ◽  
Author(s):  
Takuma Inai ◽  
Tomoya Takabayashi ◽  
Mutsuaki Edama ◽  
Masayoshi Kubo
Keyword(s):  
Contact Force ◽  
Hip Joint ◽  
Stance Phase ◽  
Hip Osteoarthritis ◽  
Contact Forces ◽  
Joint Contact Force ◽  
Joint Contact ◽  
Hip Joint Contact Force ◽  
The Relationship ◽  
Second Peak

Abstract Background: Excessive mechanical loading, in the form of the joint contact force, has been reported to promote osteoarthritis in vitro and vivo in mice. However, it has also been reported that an excessive hip adduction moment impulse during the stance phase likely contributes to the progression of hip osteoarthritis. The relationship between the hip adduction moment impulse and hip joint contact force (impulse, and first and second peaks) during the stance phase is unclear. The objective of the present study was to clarify this relationship. Methods: A public dataset pertaining to the overground walking of 84 healthy adults, in which the participants walked at a self-selected speed, was considered. The data of three trials for each participant were analyzed. The relationship between the hip adduction moment and hip joint contact force, in terms of the impulse and first and second peaks, during the stance phase was evaluated using correlation coefficients.Results: The hip adduction moment impulse during the stance phase was positively correlated with the hip joint contact force impulse and not correlated with the first and second peak hip joint contact forces. Furthermore, the first and second peak hip adduction moments during the stance phase were positively correlated with the first and second peak hip joint contact forces, respectively. Conclusions: These findings indicate that the hip joint contact force impulse during the stance phase can be used as an index to determine the risk factors for the progression of hip osteoarthritis.

scholarly journals Hip joint contact force in the emu (Dromaius novaehollandiae) during normal level walking

2008 ◽  
Vol 41 (4) ◽  
pp. 770-778 ◽  
Author(s):  
Jessica E. Goetz ◽  
Timothy R. Derrick ◽  
Douglas R. Pedersen ◽  
Duane A. Robinson ◽  
Michael G. Conzemius ◽  
...  
Keyword(s):  
Contact Force ◽  
Hip Joint ◽  
Normal Level ◽  
Joint Contact Force ◽  
Level Walking ◽  
Dromaius Novaehollandiae ◽  
Joint Contact ◽  
Hip Joint Contact Force

Simplified motion and loading compared to physiological motion and loading in a hip joint simulator

2000 ◽  
Vol 214 (3) ◽  
pp. 233-238 ◽  
Author(s):  
S L Smith ◽  
A Unsworth
Keyword(s):  
Hip Joint ◽  
Wear Test ◽  
Test Duration ◽  
Acetabular Cup ◽  
Single Plane ◽  
Wear Rates ◽  
Physiological Loading ◽  
Flexion Extension ◽  
Physiological Motion ◽  
Hip Joint Simulator

Two wear tests were conducted using the Durham Hip Joint Wear Simulator to investigate the effects of simplified motion and loading on ultra-high molecular weight polyethylene (UHMWPE) acetabular cup wear rates. Bovine serum was used as a lubricant and a gravimetric technique was used to measure wear. The first wear test duration was 7.1 × 106 cycles and investigated the effect of simplified loading. This was achieved by using full physiological motion and loading for the first 5 × 106 cycles of the test, then physiological motion with simplified loading for the final 2.1 × 106 cycles of the wear test. The UHMWPE acetabular cup wear rates using full physiological motion and loading were 32.2 and 51.7 mm3/106 cycles against zirconia and CoCrMo femoral heads respectively. Using simplified loading the cup wear rates were 30.1 and 49.2 mm3/106 cycles against zirconia and CoCrMo respectively which was not significantly different from wear rates with physiological loading. The effect of simplified motion was investigated in a second wear test of 5.0 × 106 cycles duration. Physiological loading was applied across the prosthesis with physiological motion in the flexion/extension plane only. Mean wear of the acetabular component dropped to 0.197 mm3/106 cycles. The surfaces of all the actabular cups were subject to gross examination, optical microscopy and scanning electron microscopy. No notable difference was observed between the cups subjected to physiological motion and loading and those subjected to simplified loading. The cups worn with a single plane of motion had a much smaller worn area and a notable difference in surface features to the other cups. Simplifed loading is therefore an acceptable simplification in simulator testing but simplifying motion to the flexion/extension plane axis only is unacceptable.

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