A Bipolar Artificial Hip Joint Design for Contact Impingement Reduction

2015 ◽  
Vol 1123 ◽  
pp. 164-168 ◽  
Author(s):  
Eko Saputra ◽  
Iwan Budiwan Anwar ◽  
J. Jamari ◽  
Emile van der Heide
Keyword(s):  
Molecular Weight ◽  
Range Of Motion ◽  
High Molecular Weight ◽  
Internal Rotation ◽  
Hip Joint ◽  
Acetabular Liner ◽  
Free Range ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Ultra High Molecular Weight

The acetabular liner of an artificial hip joint (AHJ) is easily damaged locally in case of impingement, i.e. in case of contact of the liner wall with the stem neck, especially when it is made from relatively soft material such as ultra high molecular weight polyethylene (UHMWPE). Frequent impingement will severely damage the acetabular liner, requiring replacement of the AHJ. The aim of this study is to reduce AHJ impingement for specific combinations of flexion, internal rotation, and adduction of the thigh, by optimizing the design of the AHJ. The presented new design is based on modifying a conventional AHJ into a bipolar version with a higher free range of motion (RoM). Results show that the proposed design is able to prevent impingement for RoM. The latter range of motion corresponds well with the requirements of Shalat.

The Effect of the Wall Thickness on Wear of an UHMWPE Acetabular Liner

2015 ◽  
Vol 1123 ◽  
pp. 196-200 ◽  
Author(s):  
J. Jamari ◽  
A. Hidayat ◽  
Eko Saputra ◽  
Iwan Budiwan Anwar ◽  
Rifky Ismail ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Wall Thickness ◽  
Contact Stresses ◽  
Thickness Variation ◽  
Wear Volume ◽  
Acetabular Liner ◽  
Element Analysis ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Ultra High Molecular Weight

A larger diameter of femoral head of artificial hip joint (AHJ) is commonly recommended for increasing range of motion (RoM) and for avoiding dislocation. Unfortunately, increasing that diameter will reduce the material liner thickness of the acetabular component. The behaviour of the AHJ contact system with thickness variation of the Ultra High Molecular Weight Polyethylene (UHMWPE) acetabular liner was studied numerically and experimentally. Finite element analysis was employed for calculating contact stresses and the wear volume was measured experimentally. Numerical results show higher contact stresses with decreasing liner wall thickness. Yet, the experimental results suggest that wear decreases as well with decreasing wall thickness. These findings are important in designing an optimised acetabular liner for larger RoM.

scholarly journals Numerical Simulation of Artificical Hip Joint Movement for Western and Japanese-Style Activities

2014 ◽  
Vol 66 (3) ◽  
Author(s):  
Eko Saputra ◽  
Iwan Budiwan Anwar ◽  
Rifky Ismail ◽  
J. Jamari ◽  
Emile van Der Heide
Keyword(s):  
Numerical Simulation ◽  
Range Of Motion ◽  
Hip Joint ◽  
Human Activities ◽  
Joint Movement ◽  
Acetabular Liner ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Cup Position ◽  
Prosthetic Impingement

A numerical simulation model for observing the artificial hip joint movement with respect to the range of motion during human activities is presented in this paper. There were two human activities discussed, i.e. Western-style and Japanese-style. Previous investigation has reported the range of motion on the artificial hip joint for Western-style and Japanese-style, measured from the postoperative total hip arthroplasty patients. The aim of this investigation is to observe the probability of prosthetic impingement and to calculate the von Mises stress during these activities using finite element analysis (FEA). The Western-style activities consist of picking up, getting up and sitting, while the Japanese-style activities consist of sitting on legs with fully flexed at the knee (seiza), squatting and sitting on legs with fully flexed at the knee (zarei). The FEA uses a three-dimensional nonlinear model and considers the variation of the acetabular liner cup positions. Result shows that a prosthetic impingement is found in the Western’s picking up activity. This activity induces a prosthetic impingement in a certain the acetabular liner cup position. In the Japanese-style activities there is no prosthetic impingement observed. However, a critical value in the range of motion was observed for the Japanese’s Zarei activity for certain the acetabular liner cup position. The acetabular liner cup positions influences the probability of prosthetic impingement.

Transient elastohydrodynamic lubrication analysis of ultra-high molecular weight polyethylene hip joint replacements

2001 ◽  
Vol 216 (4) ◽  
pp. 409-420 ◽  
Author(s):  
D Jalali-Vahid ◽  
Z M Jin
Keyword(s):  
Hip Joint ◽  
Numerical Procedure ◽  
Elastohydrodynamic Lubrication ◽  
Squeeze Film ◽  
Joint Replacements ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Minimum Film Thickness ◽  
Hip Joint Replacements ◽  
Ultra High Molecular Weight

The cyclic variation in both the load and speed experienced during walking was considered in an elastohydrodynamic lubrication (EHL) analysis for artificial hip joint replacements in this study. A general numerical procedure was developed to take both the entraining and squeeze-film actions into the solution of the Reynolds equation in the spherical ball-in-socket coordinate, simultaneously with the elasticity equation, using the Newton-Raphson method. The numerical procedure developed was then applied to an example of hip joint replacements employing an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup against either a metallic or ceramic femoral head under simplified cyclic load and speed conditions. The predicted minimum film thickness was found to stay remarkably constant, despite a large change in the angular velocity and the load. This was attributed to the combined effect of entraining and squeeze-film actions in generating, replenishing and maintaining the lubricating film in artificial hip joint replacements. Furthermore, it was pointed out that the average transient minimum film thickness predicted throughout one cycle was very close to that under quasi-static conditions based upon the average angular velocity and load.

Raman tensor analysis of ultra-high molecular weight polyethylene and its application to study retrieved hip joint components

2010 ◽  
Vol 6 (9) ◽  
pp. 3583-3594 ◽  
Author(s):  
Yasuhito Takahashi ◽  
Leonardo Puppulin ◽  
Wenliang Zhu ◽  
Giuseppe Pezzotti
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Hip Joint ◽  
Tensor Analysis ◽  
Ultra High Molecular Weight
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