An Experimental Study of Metallic Transfer on Ceramic Femoral Heads

2009 ◽  
Author(s):  
Douglas M. Doud ◽  
Preston R. Beck ◽  
Donald R. Petersen ◽  
Jack E. Lemons ◽  
Alan W. Eberhardt
Keyword(s):  
Experimental Study ◽  
Femoral Head ◽  
Life Expectancy ◽  
Metal Transfer ◽  
Acetabular Cup ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Femoral Heads ◽  
Hip Replacements ◽  
Postoperative Dislocation

Postoperative dislocation of total hip replacements has been documented to occur at a rate of approximately 2.4–3.9% [1–3]. Such events may result in the transfer of titanium from the acetabular cup to the femoral head, both during the dislocation and surgical reduction of the dislocated joint [3,4]. If the head is reduced with this transfer present, the joint life expectancy, which depends on articulating surfaces remaining smooth, is reduced [4]. Although the presence of metal transfer on retrieved femoral heads after dislocation is documented, no previous studies have attempted to quantify the forces or contact stresses at which metal transfer occurs.

Double-Modular Hip Device Design Susceptible to Stress Corrosion Failure

2009 ◽  
Author(s):  
Sara A. Atwood ◽  
Eli W. Patten ◽  
Kevin J. Bozic ◽  
Lisa A. Pruitt ◽  
Michael D. Ries
Keyword(s):  
Femoral Head ◽  
Femoral Anteversion ◽  
Metal Alloy ◽  
Leg Length ◽  
Acetabular Cup ◽  
Corrosion Failure ◽  
Total Hip ◽  
Press Fit ◽  
Free Mobility ◽  
Hip Replacements

Total hip replacements restore pain-free mobility to approximately 200,000 patients in the U.S. each year [1]. A typical hip system comprises a metal alloy stem, a femoral head (ceramic or metal alloy), and a polyethylene acetabular cup fit into a metal alloy backing. A modular press-fit Morse taper is commonly used to attach the femoral head to the stem. There are also more recent designs that incorporate a second interface at the neck-stem junction (Figure 1). Increased modularity in total hip replacement design allows the surgeon to intraoperatively preserve patient anatomy such as leg length and femoral anteversion and better balance the surrounding soft tissue for optimal biomechanics. However, modularity also increases the number of mechanical junctions and interfaces in the device which may lead to complications such as corrosion, wear, and fracture.

scholarly journals Biotribology in Arthroplasty: Worn Surfaces Investigation on Ceramic Hip Femoral Heads Considering Wettability

2020 ◽  
Vol 10 (24) ◽  
pp. 8919
Author(s):  
Saverio Affatato ◽  
Alessandro Ruggiero
Keyword(s):  
Amplitude Distribution ◽  
Average Roughness ◽  
Surface Evolution ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Roughness Profile ◽  
Femoral Heads ◽  
Hip Replacements ◽  
Worn Surfaces

Ceramic-on-ceramic bearings for total hip replacement are considered the best choice to avoid problems such as osteolysis and wear, mainly related to soft bearings. The aim of this work was to investigate in a comparative way different kinds of ceramic femoral heads for total hip replacements from a biotribological point of view, discussing the results obtained in terms of topographies, presence of metal transfer (MT) phenomena, and wettability on their worn surfaces in a tribological framework. Different ceramic femoral heads derived from in vitro wear tests, retrieved form patients, and brand new total hip replacements were investigated. The patients group had an average age of 60 years (ranging from 27 to 83). In most cases, the cause of failure was aseptic loosening of the acetabular component. Roughness analyses were performed to measure the tribological surface evolution of the material; an SEM and EDS investigation on the explanted heads proves and quantified MT, while the wettability was measured through a novel optical laboratory set-up with the aim to furnish useful data in the framework of synovial lubrication phenomena acting in the tribosystem. For the average roughness measurements on explanted specimens were considered three parameters (Ra = the average area between the roughness profile and its mean line; Rt = the vertical distance from the deepest valley to the highest peak of the roughness profile; and Rsk = it is the skewness and it is a measure of the asymmetry of the amplitude distribution function. In other words, the skewness indicates whether a surface is dominated by peaks or by valleys) and their values were: Ra 0.22 ± 0.12 μm, Rt 34.5 ± 13.5 μm and Rsk −0.01 ± 11.3; on the new specimens we measured Ra 0.01 ± 0.001 μm, Rt 0.12 ± 0.09 μm, and Rsk = 5.67 ± 8.7; for the in vitro specimens they were Ra 0.05 ± 0.12 μm, Rt 0.71 ± 1.4 μm and Rsk 7.73 ± 20.6. The wettability angle measurements showed hydrophilic surfaces for all femoral heads considered in this study with small differences between the three investigated categories, allowing to discuss their effects on the biobearings’ lubrication phenomena.

Failure of an Uncemented Press-Fit Acetabular Cup in Primary Total Hip Arthroplasty

2002 ◽  
Vol 12 (4) ◽  
pp. 371-377 ◽  
Author(s):  
N. Rama Mohan ◽  
P. Grigoris ◽  
D.L. Hamblen
Keyword(s):  
Femoral Stem ◽  
Acetabular Cup ◽  
Total Hip ◽  
Press Fit ◽  
Total Hip Replacements ◽  
Locking Mechanism ◽  
Hip Replacements ◽  
The Mean ◽  
Open Position ◽  
Primary Total Hip Arthroplasty

We reviewed fifteen primary total hip replacements performed using the uncemented, non-porous coated press-fit AcSys Shearer Cup. A modular titanium straight femoral stem with a 32mm head was used in all cases. The mean age of the group containing five males and 10 females was 66 years. Eight cups have been revised for aseptic loosening at a mean of seven years and the remaining four cups are radiologically loose. At revision surgery none of the cups showed any evidence of bony ingrowth. Our 10-year results with this cup indicate an unacceptably high failure rate of 80%. Absence of bony ingrowth and the lack of a secure locking mechanism between the polyethylene liner and the metal shell are the most important causes of failure. The use of a 32mm diameter head and implantation of the cup in an open position contributed to this failure. Even though this cup is no longer manufactured, our experience suggests that all non-porous coated cups should be closely followed up.

Assessment of Titanium Alloy on Polyethylene Bearing Surfaces in Retrieved Uncemented Total Hip Replacements

1994 ◽  
Vol 208 (2) ◽  
pp. 91-95 ◽  
Author(s):  
K J Drabu ◽  
R J Michaud ◽  
P J J McCullagh ◽  
K Brummitt ◽  
R A Smith
Keyword(s):  
Titanium Alloy ◽  
Hip Arthroplasty ◽  
Surface Finish ◽  
Revision Surgery ◽  
Articular Surface ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Femoral Heads ◽  
Hip Replacements ◽  
Bone Particles

Changes to the bearing surfaces of eighteen uncemented total hip replacements retrieved at revision surgery were assessed by three-dimensional binocular microscopy, Rank Taylor Hobson talysurf measurements, scanning electron microscopy, and X-ray dispersive analysis. Abrasions on the non-articular surface of the polyethylene cups were present. Bone particles were found in tracks in the bearing surfaces of both the titanium femoral heads and the polyethylene cups and were responsible for wear of these surfaces. Although the wear of the femoral heads appeared substantial to naked eye examination, the surface finish of these surfaces remained within the British ISO standards for titanium alloy when assessed by the methods used above. This study concluded that direct contact between polyethylene and bone should be avoided in total hip arthroplasty and that ‘third body’ wear from bone particles occurred in these uncemented prostheses. Both components of this type of implant should be replaced at revision surgery and titanium should be avoided as a bearing surface in hip arthroplasty. Present methods of assessing the surface finish of titanium should be re-evaluated and more reliable ones considered.

Two Stage one Component Revision in Infected Total hip Replacements - two Case reports and Literature Review

2009 ◽  
Vol 19 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Radwane Faroug ◽  
Yousaf Shah ◽  
Michael J. H. Mccarthy ◽  
Maher Halawa
Keyword(s):  
Case Reports ◽  
Femoral Stem ◽  
Acetabular Cup ◽  
Two Stage ◽  
Total Hip ◽  
Total Hip Replacements ◽  
First Case ◽  
Hip Replacements ◽  
Component Revision

We present two cases of infected primary total hip replacements (THR) where only one of the two components exhibited loosening. Both were revised using a two stage, one component revision technique, replacing the loose component only. In the first case the acetabular component was revised leaving the original femoral stem in situ. In the second case, the femoral component was revised, leaving the original acetabular cup undisturbed. Both patients remained infection free at three and half and three years follow up respectively.

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