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

Author(s):  
Mehul A. Dharia ◽  
Danny L. Levine ◽  
Roy D. Crowninshield ◽  
Eik Siggelkow ◽  
Dale A. Degroff ◽  
...  

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.

Author(s):  
Francisco Romero ◽  
Farid Amirouche ◽  
Mark Gonzalez ◽  
Todd Render

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.


Author(s):  
Ali Merdji ◽  
Belaid Taharou ◽  
Rajshree Hillstrom ◽  
Ali Benaissa ◽  
Sandipan Roy ◽  
...  

2021 ◽  
Author(s):  
Muhammad Izzuddin Md Isa ◽  
Solehuddin Shuib ◽  
Ahmad Zafir Romli ◽  
Amran Ahmed Shokri ◽  
Iffa Mohd Arrif ◽  
...  

2000 ◽  
Vol 13 (02) ◽  
pp. 78-86 ◽  
Author(s):  
D. Tompkins ◽  
B. Bhushan ◽  
M. L. Olmstead ◽  
J. Dyce

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.


2015 ◽  
Vol 49 (2) ◽  
pp. 181 ◽  
Author(s):  
AnilThomas Oommen ◽  
VigneshPrasad Krishnamoorthy ◽  
PradeepMathew Poonnoose ◽  
RaviJacob Korula

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