Induced Stresses and Shell/Liner Micromotions in THA Components During Dislocation: A Finite Element Study

2002 ◽  
Author(s):  
Francisco Romero ◽  
Farid Amirouche ◽  
Mark Gonzalez ◽  
Todd Render
Keyword(s):  
Finite Element ◽  
Femoral Head ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Polyethylene Wear ◽  
High Stress ◽  
Head Impacts ◽  
Induced Stresses ◽  
Supporting Structures ◽  
Element Study

During total hip replacement (THR) many supporting structures for the retention of the femoral head within the acetabulum are removed. Previous studies have determined that this lack of supporting structures leads to separation of the femoral head within the UHMWPE liner. During the relocation phase the femoral head impacts with the liner creating high stress conditions that may contribute to premature polyethylene wear and instabilities.

Evaluation of femoral head damage during canine total hip replacement

2003 ◽  
Vol 16 (03) ◽  
pp. 184-190 ◽  
Author(s):  
H. Powell ◽  
A. Kohm ◽  
J. J. Lannutti ◽  
J. Dyce ◽  
I. Wood
Keyword(s):  
Electron Microscopy ◽  
Femoral Head ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Polyethylene Wear ◽  
Optical Profilometry ◽  
Total Hip ◽  
Coated Metal ◽  
Hip Reduction ◽  
Scanning Electron

SummaryThree types of hip skids and a Hohmann retractor technique were used to facilitate reduction of the prosthesis in cadaveric canine total hip replacement. The degree of damage to the femoral head was evaluated using scanning electron microscopy and optical profilometry. Standard metal and ME-92 coated metal hip skids caused severe regional scratching of the femoral head. Morphologically similar scratch patterns were also identified on femoral heads retrieved from clinical patients. Use of a plastic coated skid or the Hohmann retractor technique had no perceptible effect on surface finish, and therefore either method is acceptable in clinical practice. The use of metal hip skids cannot be recommended for hip reduction as the resultant pattern of femoral head scratching is likely to be associated with early and severe polyethylene wear.

Effectiveness of Trabecular Metal™ Acetabular Augment in Revision THR of Pelvis With Severe Acetabular Defect: A Finite Element Study

2007 ◽  
Author(s):  
Mehul A. Dharia ◽  
Danny L. Levine ◽  
Roy D. Crowninshield ◽  
Eik Siggelkow ◽  
Dale A. Degroff ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Loss ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Acetabular Defect ◽  
Trabecular Metal ◽  
Reconstructive Technique ◽  
Acetabular Defects ◽  
Acetabular Components ◽  
Element Study

Osteolysis of the pelvis after total hip replacement (THR) can result in several types of bony defects within or around the acetabulum [1]. These defects are classified into various categories based on the extent and location of the host bone loss [2, 3]. A severe acetabular defect with at least 30% of bone loss and progressive amounts of superior rim deficiencies can be classified as a Paprosky type IIIA cavitary defect [4] (Figure 1-I). A significant amount of superior migration of the cup can be expected as the deficient acetabulum with nonsupportive superior dome will be unable to support an acetabular component at the anatomic hip center without using structural allograft, custom implants or reconstruction cage [4, 5]. A new reconstructive technique (Figure 1-II) uses modular Trabecular Metal™ (TM) augments (Figure 1-III) to fill the acetabular defects at the time of revision THR so that regular hemispheric uncemented acetabular components can be used to allow for the potential of biologic fixation.

Total Hip Replacement after Failed Femoral Head and Neck Excision in Two Dogs and Two Cats

2012 ◽  
Vol 41 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Noel Fitzpatrick ◽  
Laura Pratola ◽  
Russell Yeadon ◽  
Christos Nikolaou ◽  
Michael Hamilton ◽  
...  
Keyword(s):  
Femoral Head ◽  
Head And Neck ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Total Hip

Finite Element Analysis (FEA) of the Different Cement Mixture for Total Hip Replacement

2021 ◽  
Author(s):  
Muhammad Izzuddin Md Isa ◽  
Solehuddin Shuib ◽  
Ahmad Zafir Romli ◽  
Amran Ahmed Shokri ◽  
Iffa Mohd Arrif ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Element Analysis ◽  
Total Hip ◽  
Cement Mixture

Polyethylene Wear in Retrieved Canine Acetabular Components

2000 ◽  
Vol 13 (02) ◽  
pp. 78-86 ◽  
Author(s):  
D. Tompkins ◽  
B. Bhushan ◽  
M. L. Olmstead ◽  
J. Dyce
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Total Hip Replacement ◽  
Acetabular Component ◽  
Hip Replacement ◽  
Polyethylene Wear ◽  
Total Hip ◽  
Particulate Debris ◽  
Acetabular Components ◽  
Scanning Electron

SummaryThe aim of this pilot study was to define the mechanism and mode of polyethylene wear in acetabular components retrieved from seven dogs following therapeutic total hip replacement. The articular surface of each acetabular component was examined using contact profilometry and scanning electron microscopy (SEM). Peak-tovalley distance (P-V) and arithmetic average surface roughness (Ra) were calculated for each quadrant of the surface. Deformation of the regular profile of the machining lines was the least severe form of surface alteration. Randomly orientated scratches, fine tapered filaments, ripples, and coarse surface shredding were common SEM observations. Gouging of the convex surface of the cup was seen in two cases following failure of the polyethylenecement interface. Wear of the nonarticular acetabular rim suggested neck impingement in one case. P-V and Ra were significantly lower in the craniodorsal zone, compared to the average roughness of the other three quadrants (p < 0.05). Abrasion, adhesion and fatigue were the principal mechanisms of polyethylene wear, and were implicated in the production of polyethylene particulate debris. Meticulous removal of abrasive third bodies at the time of surgery, and correct orientation of the acetabular component, should reduce early and severe wear.Polyethylene wear is inevitable following metal-on-polyethylene total hip replacement. In this study, the nature of polyethylene wear in retrieved canine acetabular components was defined, using contact profilometry and scanning electron microscopy. Abrasion, adhesion and fatigue were the principal mechanisms of wear, and were implicated in the production of polyethylene particulate debris.

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