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Thomas P Schmalzried - One of the best experts on this subject based on the ideXlab platform.
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How I choose a Bearing Surface for my patients.
The Journal of arthroplasty, 2020Co-Authors: Thomas P SchmalzriedAbstract:There is insufficient clinical data to demonstrate the overall superiority of any one Bearing couple for all total hip cases. It is therefore reasonable to individualize the choice of Bearing Surface. The fundamental exercise in choosing a Bearing Surface is maximizing the benefit to risk ratio. There are at least 3 perspectives to consider: the patient's, the surgeon's, and that of the health care delivery system. The following question should be addressed on a patient-by-patient basis: what available Bearing is most likely to meet the needs of this patient, with an acceptable risk of revision surgery during his or her lifetime, is accepted in my community, and is there a means to pay for it?
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Bearing Surface options for total hip replacement in young patients
Journal of Bone and Joint Surgery American Volume, 2003Co-Authors: Christian Heisel, Mauricio Silva, Thomas P SchmalzriedAbstract:Total hip arthroplasty is one of the most successful and cost-effective surgical interventions in medicine1 and is the most effective treatment for osteoarthritis of the hip joint. Long-term studies of selected patient cohorts2-4 and the Scandinavian hip registries5,6 have demonstrated high survivorship rates after more than twenty years. On the basis of this success, total hip replacement is being performed on increasingly younger and more active patients. However, there are at least two problems that a young or active patient faces with regard to the prosthetic joint. First, the use of the implant is more intense in proportion to their physical activities7. Second, the patient's life expectancy is longer and the potential total number of loading cycles is increased proportionally. Patient-related factors contribute to implant wear regardless of the type of Bearing8. Higher patient activity results in higher wear rates8. Follow-up studies of young patients have demonstrated a relationship between the amount of wear and the age of the patient9,10, the revision rate11, osteolysis9,12,13, and aseptic loosening12. The overall rate of survival of total hip arthroplasty implants in young patients is reduced compared with that in average patient groups3. The survival rate of artificial joints in patients younger than fifty years of age is approximately 80% after ten years or more, regardless of the fixation technique and Bearing combination11,12,14-18. To our knowledge, only one recent study, by Kim et al.10, demonstrated a survival rate of 99% after ten years in patients less than fifty years of age. In chronological order, the categorical factors limiting the function and longevity of a total hip prosthesis are the surgical technique, fixation of the implant to the bone, osteolysis (often associated with wear of the Bearing), fatigue failure of the implants, and long-term skeletal remodeling. No implant system can overcome inadequate surgical technique. A …
Daniel J Berry - One of the best experts on this subject based on the ideXlab platform.
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the epidemiology of Bearing Surface usage in total hip arthroplasty in the united states
Journal of Bone and Joint Surgery American Volume, 2009Co-Authors: Kevin J Bozic, Steven M. Kurtz, Vanessa Chiu, Thomas P Vail, Harry E Rubash, Daniel J BerryAbstract:Background: Hard-on-hard Bearings offer the potential to improve the survivorship of total hip arthroplasty implants. However, the specific indications for the use of these advanced technologies remain controversial. The purpose of this study was to characterize the epidemiology of Bearing Surface utilization in total hip arthroplasty in the United States with respect to patient, hospital, geographic, and payer characteristics. Methods: The Nationwide Inpatient Sample database was used to analyze Bearing type and demographic characteristics associated with 112,095 primary total hip arthroplasties performed in the United States between October 1, 2005, and December 31, 2006. The prevalence of each type of total hip arthroplasty Bearing was calculated for population subgroups as a function of age, sex, census region, payer class, and hospital type. Results: The most commonly reported Bearing was metal-on-polyethylene (51%) followed by metal-on-metal (35%) and ceramic-on-ceramic (14%). Metal-on-polyethylene Bearings were most commonly reported in female Medicare patients who were sixty-five to seventy-four years old, while metal-on-metal and ceramic-on-ceramic Bearings were most commonly reported in privately insured male patients who were less than sixty-five years old. Thirty-three percent of patients over sixty-five years old had a hard-on-hard Bearing reported. There was substantial regional variation in Bearing usage; the highest prevalence of metal-on-polyethylene Bearings was reported in the Northeast and at nonteaching hospitals, and the highest prevalence of metal-on-metal Bearings was reported in the South and at teaching hospitals. Conclusions: The usage of total hip arthroplasty Bearings varies considerably by patient characteristics, hospital type, and geographic location throughout the United States. Despite uncertain advantages in older patients, hard-on-hard Bearings are commonly used in patients over the age of sixty-five years. Further study is necessary to define the appropriate indications for these advanced technologies in total hip arthroplasty.
Christian Heisel - One of the best experts on this subject based on the ideXlab platform.
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Bearing Surface options for total hip replacement in young patients
Journal of Bone and Joint Surgery American Volume, 2003Co-Authors: Christian Heisel, Mauricio Silva, Thomas P SchmalzriedAbstract:Total hip arthroplasty is one of the most successful and cost-effective surgical interventions in medicine1 and is the most effective treatment for osteoarthritis of the hip joint. Long-term studies of selected patient cohorts2-4 and the Scandinavian hip registries5,6 have demonstrated high survivorship rates after more than twenty years. On the basis of this success, total hip replacement is being performed on increasingly younger and more active patients. However, there are at least two problems that a young or active patient faces with regard to the prosthetic joint. First, the use of the implant is more intense in proportion to their physical activities7. Second, the patient's life expectancy is longer and the potential total number of loading cycles is increased proportionally. Patient-related factors contribute to implant wear regardless of the type of Bearing8. Higher patient activity results in higher wear rates8. Follow-up studies of young patients have demonstrated a relationship between the amount of wear and the age of the patient9,10, the revision rate11, osteolysis9,12,13, and aseptic loosening12. The overall rate of survival of total hip arthroplasty implants in young patients is reduced compared with that in average patient groups3. The survival rate of artificial joints in patients younger than fifty years of age is approximately 80% after ten years or more, regardless of the fixation technique and Bearing combination11,12,14-18. To our knowledge, only one recent study, by Kim et al.10, demonstrated a survival rate of 99% after ten years in patients less than fifty years of age. In chronological order, the categorical factors limiting the function and longevity of a total hip prosthesis are the surgical technique, fixation of the implant to the bone, osteolysis (often associated with wear of the Bearing), fatigue failure of the implants, and long-term skeletal remodeling. No implant system can overcome inadequate surgical technique. A …
Steven M. Kurtz - One of the best experts on this subject based on the ideXlab platform.
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POLYETHYLENE Bearing Surface WEAR IN REVERSE TOTAL SHOULDER ARTHROPLASTY
2018Co-Authors: Daniel W. Macdonald, M. Kraay, Clare M. Rimnac, Gerald Williams, J. Abboud, Steven M. KurtzAbstract:Utilization of reverse total shoulder arthroplasty (RTSA) has steadily increased since its 2003 introduction in the American market. Although RTSA was originally indicated for elderly, low demand patients, it is now being increasingly used to treat rotator cuff arthropathy, humeral fractures, neoplasms and failed total and hemi shoulder arthroplasty. There is, therefore, a growing interest in Bearing Surface wear of RTSA polyethylene humeral liners. In the current study, we examined humeral liners retrieved as part of an IRB approved study to determine the amount of Bearing Surface wear. We hypothesized that wear of the Bearing Surface by intentional contact with the glenosphere (mode I) would be minor compared to that produced by scapular notching and impingement of the humeral liner (mode II).Twenty-three retrieved humeral liners were retrieved at revision surgery after an average of 1.5 years implantation time. The average age at implantation was 68 years (range 50–85). Shoulders were revised for loose...
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POLYETHYLENE Bearing Surface WEAR IN REVERSE TOTAL SHOULDER ARTHROPLASTY
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Daniel W. Macdonald, M. Kraay, Clare M. Rimnac, Gerald Williams, J. Abboud, Steven M. KurtzAbstract:Utilization of reverse total shoulder arthroplasty (RTSA) has steadily increased since its 2003 introduction in the American market. Although RTSA was originally indicated for elderly, low demand patients, it is now being increasingly used to treat rotator cuff arthropathy, humeral fractures, neoplasms and failed total and hemi shoulder arthroplasty. There is, therefore, a growing interest in Bearing Surface wear of RTSA polyethylene humeral liners. In the current study, we examined humeral liners retrieved as part of an IRB approved study to determine the amount of Bearing Surface wear. We hypothesized that wear of the Bearing Surface by intentional contact with the glenosphere (mode I) would be minor compared to that produced by scapular notching and impingement of the humeral liner (mode II). Twenty-three retrieved humeral liners were retrieved at revision surgery after an average of 1.5 years implantation time. The average age at implantation was 68 years (range 50–85). Shoulders were revised for loosening (7), instability (6), infection (6), pain (2), and other/unknown reasons (2). The liners were scanned using microCT at a resolution of 50 µm and then registered against unworn Surfaces to estimate the Bearing Surface wear depth. The depth of Surface penetration due to impingement of the liner with surrounding structures was measured and the location of the deepest penetration was noted. Mode I wear of the Bearing Surface was detectable for five of the retrieved liners. The penetration depth was 100 µm or less for four of the liners and approximately 250 microns for the fifth liner. It was noted that the liners with discernable mode I wear were those with longer implantation times (average 2.4 years). Material loss and abrasion of the rim due to mode II wear was noted with measurable penetration in 18 of the liners. Mode II wear penetrated to the Bearing Surface in 11 liners. It was generally noted that volumetric material loss was dominated by mode II wear (Figure 1). In this study of short to medium term retrieved RTSA humeral liners, mode I wear of the Bearing Surface was a minor source of material loss. Mode II wear due to scapular notching or impingement of the rim was the dominant source of volumetric wear. This is in agreement with a previous study that we have performed on a smaller cohort of seven liners. It is noteworthy that we were able to detect measurable mode I wear for liners with moderate implantation times. The quantity of Bearing Surface wear that will be seen in long term retrievals remains unknown at this time.
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the epidemiology of Bearing Surface usage in total hip arthroplasty in the united states
Journal of Bone and Joint Surgery American Volume, 2009Co-Authors: Kevin J Bozic, Steven M. Kurtz, Vanessa Chiu, Thomas P Vail, Harry E Rubash, Daniel J BerryAbstract:Background: Hard-on-hard Bearings offer the potential to improve the survivorship of total hip arthroplasty implants. However, the specific indications for the use of these advanced technologies remain controversial. The purpose of this study was to characterize the epidemiology of Bearing Surface utilization in total hip arthroplasty in the United States with respect to patient, hospital, geographic, and payer characteristics. Methods: The Nationwide Inpatient Sample database was used to analyze Bearing type and demographic characteristics associated with 112,095 primary total hip arthroplasties performed in the United States between October 1, 2005, and December 31, 2006. The prevalence of each type of total hip arthroplasty Bearing was calculated for population subgroups as a function of age, sex, census region, payer class, and hospital type. Results: The most commonly reported Bearing was metal-on-polyethylene (51%) followed by metal-on-metal (35%) and ceramic-on-ceramic (14%). Metal-on-polyethylene Bearings were most commonly reported in female Medicare patients who were sixty-five to seventy-four years old, while metal-on-metal and ceramic-on-ceramic Bearings were most commonly reported in privately insured male patients who were less than sixty-five years old. Thirty-three percent of patients over sixty-five years old had a hard-on-hard Bearing reported. There was substantial regional variation in Bearing usage; the highest prevalence of metal-on-polyethylene Bearings was reported in the Northeast and at nonteaching hospitals, and the highest prevalence of metal-on-metal Bearings was reported in the South and at teaching hospitals. Conclusions: The usage of total hip arthroplasty Bearings varies considerably by patient characteristics, hospital type, and geographic location throughout the United States. Despite uncertain advantages in older patients, hard-on-hard Bearings are commonly used in patients over the age of sixty-five years. Further study is necessary to define the appropriate indications for these advanced technologies in total hip arthroplasty.
Michael Bushelow - One of the best experts on this subject based on the ideXlab platform.
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An investigation into PEEK-on-PEEK as a Bearing Surface candidate for cervical total disc replacement
The Spine Journal, 2012Co-Authors: Markus Kraft, David Koch, Michael BushelowAbstract:Abstract Background context Total disc replacement (TDR) is a relatively new reconstructive non-fusion technology for the spine that aims to overcome some of the limitations of fusion technology. The first generation artificial discs were mainly based on well-known material combinations from total hip replacement. Purpose To evaluate the feasibility of PEEK-on-PEEK as a Bearing Surface material for use in cervical TDR. Study design In vitro biotribological study including the assessment of different parameters, including the influence of radial clearance, axial load, and angular motion on the wear performance of a PEEK-on-PEEK Bearing. Methods PEEK-on-PEEK Bearing couples with ball-and-socket articulation were prepared using standard production methods. Two groups of Bearing couples, one with large radial clearances and the other with small radial clearances, were manufactured for testing. Wear tests were performed using a servo-hydraulic wear simulator that allowed controlled motions to be applied in three axes corresponding to flexion-extension, lateral bending, and axial rotation. In addition, a dynamic axial compressive load was applied to simulate the weight of the head. All tests were performed at 37°C (±2°C) in bovine calf serum with a 30 g/l protein concentration. In the first test series, the influence of the radial clearance on the wear behavior was evaluated using the load and motion parameters for cervical TDR as defined in the ISO standard 18192-1. Subsequent tests were performed to check if Surface degradation was influenced by thermal effects. Finally, in a third series of tests, the effect of load and motion profiles on wear performance was investigated by applying increased loads and corresponding motion parameters for lumbar TDR as defined in the ISO standard 18192-1. Results The measured wear rates for a PEEK-on-PEEK Bearing under cervical test conditions were considerably larger than those of similar testing using UHMWPE-on-CoCr and seemed to depend on initial radial clearances. The PEEK Bearing Surfaces exhibited severe Surface degradation for large and small clearances, but the group with smaller clearances seemed to have less severe damage. Thermal effects were not found to play a role in the Surface degradation, as the temperature near the Bearing Surface was measured and found to vary only a few degrees during testing. A change of the wear test parameters to simulate lumbar loading resulted in a considerable wear rate reduction as well as in the preservation of the Bearing Surfaces. Conclusions It was found that a cervical TDR using a PEEK-on-PEEK Bearing may be subjected to severe long-term degradation of the Bearing Surfaces. In this study, the use of PEEK as an articulation material for cervical TDR was found to be sensitive to loading conditions as well as to the initial clearance of the Bearing Surfaces. Despite the excellent properties of PEEK as an implant material, its use for articulating Surfaces for cervical TDR must be critically reviewed.
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An investigation into PEEK-on-PEEK as a Bearing Surface candidate for cervical total disc replacement
Spine Journal, 2012Co-Authors: Markus Kraft, David K. Koch, Michael BushelowAbstract:Background context: Total disc replacement (TDR) is a relatively new reconstructive non-fusion technology for the spine that aims to overcome some of the limitations of fusion technology. The first generation artificial discs were mainly based on well-known material combinations from total hip replacement. Purpose: To evaluate the feasibility of PEEK-on-PEEK as a Bearing Surface material for use in cervical TDR. Study design: In vitro biotribological study including the assessment of different parameters, including the influence of radial clearance, axial load, and angular motion on the wear performance of a PEEK-on-PEEK Bearing. Methods: PEEK-on-PEEK Bearing couples with ball-and-socket articulation were prepared using standard production methods. Two groups of Bearing couples, one with large radial clearances and the other with small radial clearances, were manufactured for testing. Wear tests were performed using a servo-hydraulic wear simulator that allowed controlled motions to be applied in three axes corresponding to flexion-extension, lateral bending, and axial rotation. In addition, a dynamic axial compressive load was applied to simulate the weight of the head. All tests were performed at 37°C (±2°C) in bovine calf serum with a 30 g/l protein concentration. In the first test series, the influence of the radial clearance on the wear behavior was evaluated using the load and motion parameters for cervical TDR as defined in the ISO standard 18192-1. Subsequent tests were performed to check if Surface degradation was influenced by thermal effects. Finally, in a third series of tests, the effect of load and motion profiles on wear performance was investigated by applying increased loads and corresponding motion parameters for lumbar TDR as defined in the ISO standard 18192-1. Results: The measured wear rates for a PEEK-on-PEEK Bearing under cervical test conditions were considerably larger than those of similar testing using UHMWPE-on-CoCr and seemed to depend on initial radial clearances. The PEEK Bearing Surfaces exhibited severe Surface degradation for large and small clearances, but the group with smaller clearances seemed to have less severe damage. Thermal effects were not found to play a role in the Surface degradation, as the temperature near the Bearing Surface was measured and found to vary only a few degrees during testing. A change of the wear test parameters to simulate lumbar loading resulted in a considerable wear rate reduction as well as in the preservation of the Bearing Surfaces. Conclusions: It was found that a cervical TDR using a PEEK-on-PEEK Bearing may be subjected to severe long-term degradation of the Bearing Surfaces. In this study, the use of PEEK as an articulation material for cervical TDR was found to be sensitive to loading conditions as well as to the initial clearance of the Bearing Surfaces. Despite the excellent properties of PEEK as an implant material, its use for articulating Surfaces for cervical TDR must be critically reviewed. © 2012 Elsevier Inc. All rights reserved.