The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
A V F Nargol - One of the best experts on this subject based on the ideXlab platform.
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volumetric wear assessment of failed metal on metal Hip Resurfacing prostheses
Wear, 2011Co-Authors: J Lord, D J Langton, A V F Nargol, T J JoyceAbstract:Abstract Recent advancements in Hip arthroplasty have allowed the operation to boast excellent results and high survivorsHip. However, failures do still occur and a major cause is complications arising from wear debris. It is essential therefore that debris is minimized by reducing wear at the bearing surface. One proposed method of achieving this wear reduction is through the use of metal-on-metal articulations. One of the latest manifestations of this biomaterial combination is in designs of Hip Resurfacing which are aimed at younger, more active patients who might wear out a conventional metal-on-polymer Hip prosthesis. However, do these metal-on-metal Hip Resurfacings show less wear when implanted into patients? Using a co-ordinate measuring machine and a bespoke computer program, volumetric wear measurements for retrieved Articular Surface Replacements (ASR™, DePuy) metal-on-metal Hip Resurfacings were undertaken. Thirty-two femoral heads and twenty-two acetabular cups were measured. Acetabular cups exhibited mean volumetric wear of 29.00 mm3 (range 1.35–109.72 mm3) and a wear rate of 11.02 mm3/year (range 0.30–63.59 mm3/year). Femoral heads exhibited mean wear of 22.41 mm3 (range 0.72–134.22 mm3) and a wear rate of 8.72 mm3/year (range 0.21–31.91 mm3/year). In the 22 cases where both head and cup from the same prosthesis were available, mean total wear rates of 21.66 mm3/year (range 0.51–95.50 mm3/year) were observed. Compared with in many vitro tests, these are significantly higher than those expected in a well functioning metal-on-metal Hip Resurfacing prosthesis and are of concern.
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reducing metal ion release following Hip Resurfacing arthroplasty
Orthopedic Clinics of North America, 2011Co-Authors: D J Langton, T J Joyce, J Lord, M Van Orsouw, Navjeet Mangat, Koen De Smet, A V F NargolAbstract:Recent guidelines have suggested that routine postoperative care of patients with metal-on-metal Hip prostheses should involve metal ion analysis. This study sought to investigate the relationsHip between bearing surface wear rates of metal components and serum metal ion analysis and also to quantify the incidence of excessive increases in serum metal ion concentrations post?Hip Resurfacing arthroplasty.
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adverse reaction to metal debris following Hip Resurfacing the influence of component type orientation and volumetric wear
Journal of Bone and Joint Surgery-british Volume, 2011Co-Authors: D J Langton, T J Joyce, S S Jameson, J Lord, M Van Orsouw, James P Holland, A V F Nargol, K De SmetAbstract:We sought to establish the incidence of joint failure secondary to adverse reaction to metal debris (ARMD) following metal-on-metal Hip Resurfacing in a large, three surgeon, multicentre study involving 4226 Hips with a follow-up of 10 to 142 months. Three implants were studied: the Articular Surface Replacement; the Birmingham Hip Resurfacing; and the Conserve Plus. Retrieved implants underwent analysis using a co-ordinate measuring machine to determine volumetric wear. There were 58 failures associated with ARMD. The median chromium and cobalt concentrations in the failed group were significantly higher than in the control group (p
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early failure of metal on metal bearings in Hip Resurfacing and large diameter total Hip replacement a consequence of excess wear
Journal of Bone and Joint Surgery-british Volume, 2010Co-Authors: D J Langton, T J Joyce, S S Jameson, Nadim J Hallab, S Natu, A V F NargolAbstract:Early failure associated with adverse reactions to metal debris is an emerging problem after Hip Resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal Resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total Hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p < 0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal Hip Resurfacing and replacement.
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blood metal ion concentrations after Hip Resurfacing arthroplasty a comparative study of articular surface replacement and birmingham Hip Resurfacing arthroplasties
Journal of Bone and Joint Surgery-british Volume, 2009Co-Authors: D J Langton, T J Joyce, Andrew P Sprowson, M Reed, I Carluke, P Partington, A V F NargolAbstract:There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available Hip Resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) Hip Resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p 45° and anteversion angles of 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55°. A significant relationsHip was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p 20°. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p
G W Blunn - One of the best experts on this subject based on the ideXlab platform.
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development of the lima ceramic Hip Resurfacing system the effect of bending and torque at the titanium ceramic taper junction
Orthopaedic Proceedings, 2018Co-Authors: H Khan, Jay Meswania, F Riva, M Pressacco, A Panagiotidou, M J Coathup, G W BlunnAbstract:BackgroundHip Resurfacing has advantages for the young active patient with arthritis; maintaining a large range of motion, preserving bone stock, and reduced dislocation risk. However high serum metal ion levels with metal-on-metal Resurfacing, and their clinical implications, has led to a decline in the use of Hip Resurfacing. Ceramic bearing surfaces display the lowest frictional torque and excellent wear rates. Recent developments have enabled large, strong ceramic materials to be used as Resurfacing components. Any wear debris that is generated from these articulations is inert. However an all-ceramic Hip Resurfacing could be at risk of fracture at the head-stem junction. A new ceramic Hip Resurfacing system with a titanium-ceramic modular taper junction has been developed. The introduction of a taper introduces the potential for fretting corrosion; we sought to determine the extent of this in an in-vitro model, and compared this prosthesis to the conventional 12/14 titanium-cobalt chrome (Ti6Al4V-CoC...
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development of the lima ceramic Hip Resurfacing system the effect of bending and torque at the titanium ceramic taper junction
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: H Khan, Jay Meswania, F Riva, M Pressacco, A Panagiotidou, M J Coathup, G W BlunnAbstract:Background Hip Resurfacing has advantages for the young active patient with arthritis; maintaining a large range of motion, preserving bone stock, and reduced dislocation risk. However high serum metal ion levels with metal-on-metal Resurfacing, and their clinical implications, has led to a decline in the use of Hip Resurfacing. Ceramic bearing surfaces display the lowest frictional torque and excellent wear rates. Recent developments have enabled large, strong ceramic materials to be used as Resurfacing components. Any wear debris that is generated from these articulations is inert. However an all-ceramic Hip Resurfacing could be at risk of fracture at the head-stem junction. A new ceramic Hip Resurfacing system with a titanium-ceramic modular taper junction has been developed. The introduction of a taper introduces the potential for fretting corrosion; we sought to determine the extent of this in an in-vitro model, and compared this prosthesis to the conventional 12/14 titanium-cobalt chrome (Ti6Al4V-CoCr) taper junction. Methods To simulate the gait cycle, sinusoidal cyclical loads between 300N-2300N, at a frequency of 3Hz, were applied to different head-neck offsets generating different bending moments and torques. The effect of increasing the bending moment and frictional torque were tested separately. Furthermore, the Resurfacing head was mounted in a fixture held with just the stem, thus representing complete bone resorption under the head. An electrochemical assessment using potentiostatic tests at an applied potential of 200mV, was used to measure the fretting current (μA) and current amplitude (μA). In a short-term 1000 cycle test, six neck lengths (short to xxx-long) of the Ti6Al4V-CoCr taper were compared to the standard neutral (concentric), and 3mm A/P offset stem options for the Resurfacing design. To represent frictional torque, four increments of increasing torque (2-4-6-8Nm) were applied to both tapers. In a long term test with the Resurfacing stem, the worst-case scenario of the eccentric offset option and 8Nm of torque were applied, and potentiostatic measurements were taken every million cycles, up to 10 million cycles. Results For bending moment through the centre of the head, the standard neutral Resurfacing taper displayed equivalent fretting current (1.35μA) compared to its conventional taper equivalent, the short 12/14 Ti6Al4V-CoCr taper (Fig. 1a). That was despite the bending moment through the Resurfacing taper being higher due to the offset nature of its taper in relation to the centre of the head. For applied torque, the Resurfacing taper displayed reduced average fretting current and average maximum fretting current when compared to the conventional taper (Fig. 1b), though this did not reach statistical significance (Kruskal-Wallis test). Under long term testing for worst-case bending and torque, the Resurfacing taper displayed low fretting currents ( Conclusion When compared to the gold-standard taper junction, the LIMA ceramic Hip Resurfacing displays equivalent fretting corrosion for bending moment and improved fretting corrosion for frictional torque. Across long term testing, stable and low fretting currents at this taper junction highlight its potential in clinical use.
D J Langton - One of the best experts on this subject based on the ideXlab platform.
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volumetric wear assessment of failed metal on metal Hip Resurfacing prostheses
Wear, 2011Co-Authors: J Lord, D J Langton, A V F Nargol, T J JoyceAbstract:Abstract Recent advancements in Hip arthroplasty have allowed the operation to boast excellent results and high survivorsHip. However, failures do still occur and a major cause is complications arising from wear debris. It is essential therefore that debris is minimized by reducing wear at the bearing surface. One proposed method of achieving this wear reduction is through the use of metal-on-metal articulations. One of the latest manifestations of this biomaterial combination is in designs of Hip Resurfacing which are aimed at younger, more active patients who might wear out a conventional metal-on-polymer Hip prosthesis. However, do these metal-on-metal Hip Resurfacings show less wear when implanted into patients? Using a co-ordinate measuring machine and a bespoke computer program, volumetric wear measurements for retrieved Articular Surface Replacements (ASR™, DePuy) metal-on-metal Hip Resurfacings were undertaken. Thirty-two femoral heads and twenty-two acetabular cups were measured. Acetabular cups exhibited mean volumetric wear of 29.00 mm3 (range 1.35–109.72 mm3) and a wear rate of 11.02 mm3/year (range 0.30–63.59 mm3/year). Femoral heads exhibited mean wear of 22.41 mm3 (range 0.72–134.22 mm3) and a wear rate of 8.72 mm3/year (range 0.21–31.91 mm3/year). In the 22 cases where both head and cup from the same prosthesis were available, mean total wear rates of 21.66 mm3/year (range 0.51–95.50 mm3/year) were observed. Compared with in many vitro tests, these are significantly higher than those expected in a well functioning metal-on-metal Hip Resurfacing prosthesis and are of concern.
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reducing metal ion release following Hip Resurfacing arthroplasty
Orthopedic Clinics of North America, 2011Co-Authors: D J Langton, T J Joyce, J Lord, M Van Orsouw, Navjeet Mangat, Koen De Smet, A V F NargolAbstract:Recent guidelines have suggested that routine postoperative care of patients with metal-on-metal Hip prostheses should involve metal ion analysis. This study sought to investigate the relationsHip between bearing surface wear rates of metal components and serum metal ion analysis and also to quantify the incidence of excessive increases in serum metal ion concentrations post?Hip Resurfacing arthroplasty.
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adverse reaction to metal debris following Hip Resurfacing the influence of component type orientation and volumetric wear
Journal of Bone and Joint Surgery-british Volume, 2011Co-Authors: D J Langton, T J Joyce, S S Jameson, J Lord, M Van Orsouw, James P Holland, A V F Nargol, K De SmetAbstract:We sought to establish the incidence of joint failure secondary to adverse reaction to metal debris (ARMD) following metal-on-metal Hip Resurfacing in a large, three surgeon, multicentre study involving 4226 Hips with a follow-up of 10 to 142 months. Three implants were studied: the Articular Surface Replacement; the Birmingham Hip Resurfacing; and the Conserve Plus. Retrieved implants underwent analysis using a co-ordinate measuring machine to determine volumetric wear. There were 58 failures associated with ARMD. The median chromium and cobalt concentrations in the failed group were significantly higher than in the control group (p
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early failure of metal on metal bearings in Hip Resurfacing and large diameter total Hip replacement a consequence of excess wear
Journal of Bone and Joint Surgery-british Volume, 2010Co-Authors: D J Langton, T J Joyce, S S Jameson, Nadim J Hallab, S Natu, A V F NargolAbstract:Early failure associated with adverse reactions to metal debris is an emerging problem after Hip Resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal Resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total Hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p < 0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal Hip Resurfacing and replacement.
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blood metal ion concentrations after Hip Resurfacing arthroplasty a comparative study of articular surface replacement and birmingham Hip Resurfacing arthroplasties
Journal of Bone and Joint Surgery-british Volume, 2009Co-Authors: D J Langton, T J Joyce, Andrew P Sprowson, M Reed, I Carluke, P Partington, A V F NargolAbstract:There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available Hip Resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) Hip Resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p 45° and anteversion angles of 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55°. A significant relationsHip was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p 20°. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p
D W Murray - One of the best experts on this subject based on the ideXlab platform.
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the correlation of wear with histological features after failed Hip Resurfacing arthroplasty
Journal of Bone and Joint Surgery American Volume, 2013Co-Authors: George Grammatopoulos, D W Murray, H S Gill, Hemant Pandit, S Glynjones, Amir Kamali, Francesca Maggiani, N A AthanasouAbstract:Background: Tissue necrosis and a macrophage and perivascular lymphocytic infiltrate are commonly seen in periprosthetic tissues around metal-on-metal Hip Resurfacing implants, including pseudotumors associated with these implants. The purpose of the present study was to correlate pathological changes in periprosthetic tissues with clinical findings and the amount of implant-derived metal wear. Methods: We analyzed morphological changes in the periprosthetic soft tissues around fifty-six failed metal-on-metal Hip Resurfacing implants. The most common reason for failure was the presence of a symptomatic pseudotumor (n = 45). The extent of necrosis and the nature of the inflammatory cell infiltrate, including aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), was evaluated semiquantitatively. Bearing surface wear was determined for all patients. Prostheses were considered to be highly worn if the total linear wear rate was ≥4 μm/yr. Results: Substantial necrosis and a heavy macrophage infiltrate were noted in most periprosthetic tissues, including all pseudotumors, many of which contained a prominent ALVAL infiltrate. Most pseudotumors (80%) were associated with highly worn prostheses. It was noted that the extent of necrosis and macrophage infiltration correlated with the volume of generated metal wear. Although increased wear volume moderately correlated with a high ALVAL response, all pseudotumors associated with low wear had a strong ALVAL response. Conclusions: The majority of pseudotumors are associated with increased implant wear. This increased wear is associated with soft-tissue necrosis and a heavy nonspecific foreign-body macrophage response coupled with a variable adaptive or specific immune response (ALVAL). A minority of pseudotumors are associated with low wear and a prominent immune response. These findings confirm that minimizing wear from metal-on-metal Hip Resurfacing arthroplasty prostheses would lead to a reduction in the incidence of pseudotumor. However, a small number of pseudotumors are still likely to occur, which may be due to an exacerbated adaptive immune response. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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individual motion patterns during gait and sit to stand contribute to edge loading risk in metal on metal Hip Resurfacing
Proceedings of the Institution of Mechanical Engineers Part H: Journal of Engineering in Medicine, 2013Co-Authors: Stephen J Mellon, D W Murray, Hemant Pandit, George Grammatopoulos, Michael Skipper Andersen, Elise Pegg, H S GillAbstract:The occurrence of pseudotumours (soft tissue masses relating to the Hip joint) following metal-on-metal Hip Resurfacing arthroplasty has been associated with higher than normal bearing wear and high serum metal ion levels although both these findings do not necessarily coexist. The purpose of this study was to examine patient activity patterns and their influence on acetabular component edge loading in a group of subjects with known serum metal ion levels. Fifteen subjects with metal-on-metal Hip Resurfacing arthroplasty (eight males and seven females) were recruited for motion analysis followed by computed tomography scans. They were divided into three groups based on their serum metal ion levels and the orientation of their acetabular component: well-positioned acetabular component with low metal ions, mal-positioned acetabular component with low metal ions and mal-positioned acetabular component with high ions. A combination of motion analysis, subject-specific modelling (AnyBody Modeling System, Aalbo...
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the ten year survival of the birmingham Hip Resurfacing an independent series
Journal of Bone and Joint Surgery-british Volume, 2012Co-Authors: D W Murray, H S Gill, Hemant Pandit, George Grammatopoulos, R Gundle, P MclardysmithAbstract:Recent events have highlighted the importance of implant design for survival and wear-related complications following metal-on-metal Hip Resurfacing arthroplasty. The mid-term survival of the most widely used implant, the Birmingham Hip Resurfacing (BHR), has been described by its designers. The aim of this study was to report the ten-year survival and patient-reported functional outcome of the BHR from an independent centre. In this cohort of 554 patients (646 BHRs) with a mean age of 51.9 years (16.5 to 81.5) followed for a mean of eight years (1 to 12), the survival and patient-reported functional outcome depended on gender and the size of the implant. In female Hips (n = 267) the ten-year survival was 74% (95% confidence interval (CI) 83 to 91), the ten-year revision rate for pseudotumour was 7%, the mean Oxford Hip score (OHS) was 43 (sd 8) and the mean UCLA activity score was 6.4 (sd 2). In male Hips (n = 379) the ten-year survival was 95% (95% CI 92.0 to 97.4), the ten-year revision rate for pseudotumour was 1.7%, the mean OHS was 45 (sd 6) and the mean UCLA score was 7.6 (sd 2). In the most demanding subgroup, comprising male patients aged < 50 years treated for primary osteoarthritis, the survival was 99% (95% CI 97 to 100). This study supports the ongoing use of Resurfacing in young active men, who are a subgroup of patients who tend to have problems with conventional THR. In contrast, the results in women have been poor and we do not recommend metal-on-metal Resurfacing in women. Continuous follow-up is recommended because of the increasing incidence of pseudotumour with the passage of time.
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characterization of metal wear nanoparticles in pseudotumor following metal on metal Hip Resurfacing
Nanomedicine: Nanotechnology Biology and Medicine, 2011Co-Authors: Youngmin Kwon, Zhidao Xia, Shahid Mehmood, Clive Downing, Kerstin Jurkschat, D W MurrayAbstract:Abstract Biopsies from a typical case of pseudotumor following metal-on-metal Hip Resurfacing (MoMHR) were analyzed using light and transmission electron microscopy, backscatter scanning electron microscopy and energy dispersive x-ray spectrometry (EDS). Heavy macrophage infiltration was observed in all black pigmented specimens. Metal nanoparticles (NPs) were observed exclusively within phagosomes of living macrophages and fragments of dead macrophages. Although dead fibroblasts were found to be juxtaposed with dead and disintegrated macrophages, the NPs were not seen within either live or dead fibroblasts. Chromium (Cr) but not cobalt (Co) was the predominant component of the remaining wear NPs in tissue. The current study finding suggests that corrosion of Co in phagosomes of macrophages and resultant Co ion release lead to tissue necrosis and adverse soft tissue reactions (pseudotumors). Further studies are required to elucidate the precise mechanism of intracellular corrosion of metal NPs and the long-term toxicity of the Cr remaining in the peri-prosthetic tissues. From the Clinical Editor In this study of metal-on-metal Hip Resurfacing-related tissue necrosis and pseudotumor formation, corrosion and decomposition of metallic cobalt in phagosomes of macrophages and resultant cobalt ion release were demonstrated to be the key elements of pathogenesis.
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Hip Resurfacing and pseudotumour
Hip International, 2011Co-Authors: D W Murray, Hemant Pandit, George Grammatopoulos, R Gundle, C L M H Gibbons, D Whitwell, A Taylor, S Glynjones, S Ostlere, H S GillAbstract:Metal on metal Hip Resurfacing has been used widely over the last ten years but there has been recent concern about destructive soft tissue reactions, which have been called pseudotumours by some authors. This has generated considerable controversy. This review explains why pseudotumours occur after Resurfacing and how they can be prevented. It also supports the continued use of Resurfacing in appropriate patients by appropriately trained surgeons.
T J Joyce - One of the best experts on this subject based on the ideXlab platform.
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volumetric wear assessment of failed metal on metal Hip Resurfacing prostheses
Wear, 2011Co-Authors: J Lord, D J Langton, A V F Nargol, T J JoyceAbstract:Abstract Recent advancements in Hip arthroplasty have allowed the operation to boast excellent results and high survivorsHip. However, failures do still occur and a major cause is complications arising from wear debris. It is essential therefore that debris is minimized by reducing wear at the bearing surface. One proposed method of achieving this wear reduction is through the use of metal-on-metal articulations. One of the latest manifestations of this biomaterial combination is in designs of Hip Resurfacing which are aimed at younger, more active patients who might wear out a conventional metal-on-polymer Hip prosthesis. However, do these metal-on-metal Hip Resurfacings show less wear when implanted into patients? Using a co-ordinate measuring machine and a bespoke computer program, volumetric wear measurements for retrieved Articular Surface Replacements (ASR™, DePuy) metal-on-metal Hip Resurfacings were undertaken. Thirty-two femoral heads and twenty-two acetabular cups were measured. Acetabular cups exhibited mean volumetric wear of 29.00 mm3 (range 1.35–109.72 mm3) and a wear rate of 11.02 mm3/year (range 0.30–63.59 mm3/year). Femoral heads exhibited mean wear of 22.41 mm3 (range 0.72–134.22 mm3) and a wear rate of 8.72 mm3/year (range 0.21–31.91 mm3/year). In the 22 cases where both head and cup from the same prosthesis were available, mean total wear rates of 21.66 mm3/year (range 0.51–95.50 mm3/year) were observed. Compared with in many vitro tests, these are significantly higher than those expected in a well functioning metal-on-metal Hip Resurfacing prosthesis and are of concern.
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reducing metal ion release following Hip Resurfacing arthroplasty
Orthopedic Clinics of North America, 2011Co-Authors: D J Langton, T J Joyce, J Lord, M Van Orsouw, Navjeet Mangat, Koen De Smet, A V F NargolAbstract:Recent guidelines have suggested that routine postoperative care of patients with metal-on-metal Hip prostheses should involve metal ion analysis. This study sought to investigate the relationsHip between bearing surface wear rates of metal components and serum metal ion analysis and also to quantify the incidence of excessive increases in serum metal ion concentrations post?Hip Resurfacing arthroplasty.
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adverse reaction to metal debris following Hip Resurfacing the influence of component type orientation and volumetric wear
Journal of Bone and Joint Surgery-british Volume, 2011Co-Authors: D J Langton, T J Joyce, S S Jameson, J Lord, M Van Orsouw, James P Holland, A V F Nargol, K De SmetAbstract:We sought to establish the incidence of joint failure secondary to adverse reaction to metal debris (ARMD) following metal-on-metal Hip Resurfacing in a large, three surgeon, multicentre study involving 4226 Hips with a follow-up of 10 to 142 months. Three implants were studied: the Articular Surface Replacement; the Birmingham Hip Resurfacing; and the Conserve Plus. Retrieved implants underwent analysis using a co-ordinate measuring machine to determine volumetric wear. There were 58 failures associated with ARMD. The median chromium and cobalt concentrations in the failed group were significantly higher than in the control group (p
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early failure of metal on metal bearings in Hip Resurfacing and large diameter total Hip replacement a consequence of excess wear
Journal of Bone and Joint Surgery-british Volume, 2010Co-Authors: D J Langton, T J Joyce, S S Jameson, Nadim J Hallab, S Natu, A V F NargolAbstract:Early failure associated with adverse reactions to metal debris is an emerging problem after Hip Resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal Resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total Hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p < 0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal Hip Resurfacing and replacement.
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blood metal ion concentrations after Hip Resurfacing arthroplasty a comparative study of articular surface replacement and birmingham Hip Resurfacing arthroplasties
Journal of Bone and Joint Surgery-british Volume, 2009Co-Authors: D J Langton, T J Joyce, Andrew P Sprowson, M Reed, I Carluke, P Partington, A V F NargolAbstract:There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available Hip Resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) Hip Resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p 45° and anteversion angles of 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55°. A significant relationsHip was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p 20°. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p