3-D Model of a Total Hip Replacement In Vivo Providing Hydrodynamic Pressure and Film Thickness for Walking and Bicycling

2003 ◽  
Vol 125 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Donna M. Meyer, ◽  
John A. Tichy,
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Hydrodynamic Lubrication ◽  
Hydrodynamic Pressure ◽  
Fluid Film ◽  
Joint Fluid ◽  
Acetabular Cup ◽  
Total Hip ◽  
Pressure Distributions

Formulation of a 3-D lubrication simulation of a total hip replacement in vivo is presented using a finite difference approach. The goal is to determine if hydrodynamic lubrication is taking place, how thick the joint fluid film is and over what percentage of two gait cycles, (walking and bicycling), the hydrodynamic lubricating action is occurring, if at all. The assumption of rigid surfaces is made, which is conservative in the sense that pure hydrodynamic lubrication is well known to predict thinner films than elastohydrodynamic lubrication (EHL) for the same loading. The simulation method includes addressing the angular velocity direction changes and accurate geometry configuration for the acetabular cup and femoral head components and provides a range of results for material combinations of CoCrMo-on-UHMWPE, CoCrMo-on-CoCrMo, and alumina-on-alumina components. Results are in the form of the joint fluid film pressure distributions, load components and film thicknesses of the joint fluid, for the gait cycles of walking and bicycling. Results show hydrodynamic action occurs in only about 10% of a walking gait cycle and throughout nearly 90% of a bicycling gait. During the 10% of the walking cycle that develops hydrodynamic lubrication, the minimum fluid film thicknesses are determined to be between 0.05 μm and 1.1 μm, while the range of film thicknesses for bicycling is between 0.1 μm and 1.4 μm, and occurs over 90% of the bicycling gait. Pressure distributions for these same periods are in the range of 2 MPa to 870 MPa for walking and 1 MPa to 24 MPa for bicycling.

Acoustic Vibration and Mechanical In Vivo Analysis of the Hip Joint After a Total Hip Arthroplasty

2007 ◽  
Author(s):  
D. A. Glaser ◽  
R. D. Komistek ◽  
H. E. Cates ◽  
M. Mahfouz
Keyword(s):  
Femoral Head ◽  
Total Hip Replacement ◽  
Hip Joint ◽  
Hip Replacement ◽  
Acoustic Vibration ◽  
Valuable Insight ◽  
Acetabular Cup ◽  
Total Hip ◽  
Resonance Frequencies

The major complications following total hip replacement (THA) are implant loosening, dislocation, instability, fracture and infection. It is hypothesized that vibration, in the range of the resonance frequencies, may cause pain, bone degeneration and fracture. A further understanding of the physical response resulting from impact during femoral head sliding may lead to valuable insight pertaining to THA failure. Therefore, the first objective of this present study was to determine if frequencies propagating through the hip joint near resonant frequencies may lead to wear or loosening of the components. Recently, studies found that femoral head sliding, often referred to as hip separation, between the acetabulum cup and the femoral head does occur, which may also play a role in complications observed with THA today, but a the effects of hip separation and the causes of its occurrence has not been studied as jet. Therefore, the second objective of this study was to determine if a sound sensor, externally attached, could be used to correlate impact loading sounds from femoral head sliding in the acetabular cup. Additional objective of this study was to develop a mathematical model that better simulates the in vivo loading conditions of total hip replacement patients using in vivo fluoroscopic and ground reaction data as input.

scholarly journals Total Hip Replacement: Results of a Postal Survey of Current Practice on the Cement Fixation of the Acetabular Cup in the UK

2004 ◽  
Vol 14 (3) ◽  
pp. 155-162
Author(s):  
R. Mootanah ◽  
P. Ingle ◽  
K. Cheah ◽  
J. K. Dowell ◽  
J. C. Shelton
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Current Practice ◽  
Postal Survey ◽  
Acetabular Cup ◽  
Total Hip ◽  
The Uk

Ion release in ceramic bearings for total hip replacement: Results from an in vitro and an in vivo study

2017 ◽  
Vol 42 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Jan Philippe Kretzer ◽  
Ulrike Mueller ◽  
Marcus R. Streit ◽  
Hartmuth Kiefer ◽  
Robert Sonntag ◽  
...  
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
In Vivo Study ◽  
Ion Release ◽  
Total Hip

scholarly journals Reproduction of fretting wear at the stem—cement interface in total hip replacement

2007 ◽  
Vol 221 (8) ◽  
pp. 963-971 ◽  
Author(s):  
L Brown ◽  
H Zhang ◽  
L Blunt ◽  
S Barrans
Keyword(s):  
Bone Cement ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Fatigue Cracks ◽  
Cement Mantle ◽  
Fretting Wear ◽  
Cement Interface ◽  
Total Hip

The stem-cement interface experiences fretting wear in vivo due to low-amplitude oscillatory micromotion under physiological loading, as a consequence it is considered to play an important part in the overall wear of cemented total hip replacement. Despite its potential significance, in-vitro simulation to reproduce fretting wear has seldom been attempted and even then with only limited success. In the present study, fretting wear was successfully reproduced at the stem-cement interface through an in-vitro wear simulation, which was performed in part with reference to ISO 7206-4: 2002. The wear locations compared well with the results of retrieval studies. There was no evidence of bone cement transfer films on the stem surface and no fatigue cracks in the cement mantle. The cement surface was severely damaged in those areas in contact with the fretting zones on the stem surface, with retention of cement debris in the micropores. Furthermore, it was suggested that these micropores contributed to initiation and propagation of fretting wear. This study gave scope for further comparative study of the influence of stem geometry, stem surface finish, and bone cement brand on generation of fretting wear.

Dislocation of a dual mobility total hip replacement following fracture of the polyethylene liner

2016 ◽  
Vol 29 (03) ◽  
pp. 259-264
Author(s):  
Pierre Guillaumot ◽  
Jean-Luc Chancrin ◽  
Bertrand Vedrine
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Polyethylene Liner ◽  
Acetabular Cup ◽  
Dual Mobility ◽  
Total Hip ◽  
Initial Surgery ◽  
Acute Rupture ◽  
Cemented Cup

SummaryAn eight-year-old male English Setter was referred for management of a dislocation of a cemented dual mobility canine total hip prosthesis that occurred four months after the initial surgery. Revision surgery showed that the dislocation was associated with fracture of the ultra-high molecular weight polyethylene liner. The dislocation was successfully reduced after replacing the liner. A dual mobility acetabular component is composed of a mobile polyethylene liner inside a metallic cemented cup. Chronic wear of the components of a canine dual mobility total hip replacement has not been described previously. The use of this type of implant is fairly recent and limited long term follow-up of the implanted cases may be the explanation. Acute rupture of a polyethylene liner has never been described in humans, the only case of rupture of a polyethylene liner occurred 10 years after implantation. The case presented here of rupture of the polyethylene liner of a dual mobility total hip replacement is a hitherto unreported failure mode in this model of acetabular cup in the dog.

scholarly journals Accuracy of templating the acetabular cup size in Total Hip Replacement using conventional acetate templates on digital radiographs

2015 ◽  
Vol 6 (4) ◽  
pp. 215-219 ◽  
Author(s):  
Vignesh P. Krishnamoorthy ◽  
Rajamani Perumal ◽  
Alfred J. Daniel ◽  
Pradeep M. Poonnoose
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Acetabular Cup ◽  
Total Hip ◽  
Digital Radiographs
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