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Lee H, Kurtz MA, Gilbert JL. Reactive Oxygen Species, Electrode Potential and pH Affect CoCrMo Alloy Corrosion and Semiconducting Behavior in Simulated Inflammatory Environments. Acta Biomater 2024:S1742-7061(24)00454-9. [PMID: 39147253 DOI: 10.1016/j.actbio.2024.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 07/18/2024] [Accepted: 08/06/2024] [Indexed: 08/17/2024]
Abstract
Crevice corrosion in modular taper junctions of hip or knee replacements using cobalt-chrome-molybdenum (CoCrMo) alloys remains a clinical concern. Non-mechanically-driven corrosion has been less explored compared to mechanically assisted crevice corrosion. This study hypothesized that solution chemistry within crevices, inflammation, and cathodic electrode potential shifts during fretting result in low pH and generate reactive oxygen species (ROS), affecting oxide film behavior. This study investigated how resistance and capacitance of the CoCrMo oxide film (i.e., corrosion resistance) are modified in simulated in vivo crevice environments of modular taper junctions. Six solutions were evaluated (two pH levels: 1 and 7.4 and four hydrogen peroxide (H2O2) concentrations: 0, 0.001, 0.01 and 0.1 M). Rp versus voltage and Mott-Schottky plots were created from symmetry-based electrochemical impedance spectroscopy (sbEIS). At pH 1, the semiconductor transition to p-type occurs at more anodic potentials and higher flat band potentials were found. H2O2 decreased the flat band potential and slope in the Mott-Schottky plot. Higher H2O2 in pH 7.4 solution significantly modified the oxide film, leading to increased donor density (p = 0.0004) and a 150-fold reduction in Rp in the cathodic potential range at -1 V (p = 0.0005). The most unfavorable condition (0.1 M H2O2 pH 1) resulted in a 250-fold lower resistance compared to phosphate buffered saline (PBS) pH 7.4 at -1 V (p = 0.0013). This study highlights the corrosion susceptibility of CoCrMo under adverse chemical and potential conditions, identifying increased defects in the oxide film due to ROS, hydrogen ions and electrode potential. STATEMENT OF SIGNIFICANCE: : Corrosion of cobalt chrome molybdenum alloy caused by direct chemical attack in the crevice region of hip replacements, such as modular taper junctions, remains a clinical concern. The junction environment contains adverse chemical compositions, including high acidity and reactive oxygen species (ROS) due to inflammatory responses against the corrosion products. We simulate inflammatory environments with different pH levels and hydrogen peroxide, representative of ROS. We employ electrochemical impedance spectroscopy and apply stepwise voltage over the range induced by tribocorrosion processes. We relate the effect of adverse chemical components on corrosion and semiconducting behavior of the oxide film using Mott-Schottky analysis. This study shows how pH and ROS concentration compromises the oxide film potentially leading to non-mechanically induced corrosion.
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Affiliation(s)
- Hwaran Lee
- Clemson - Medical University of South Carolina Bioengineering Program, Department of Bioengineering, Clemson University, Bioengineering Building, 101D, MSC 501, 68 Presidents St, BE 325, Medical University of South Carolina, Charleston, SC 29425
| | - Michael A Kurtz
- Clemson - Medical University of South Carolina Bioengineering Program, Department of Bioengineering, Clemson University, Bioengineering Building, 101D, MSC 501, 68 Presidents St, BE 325, Medical University of South Carolina, Charleston, SC 29425
| | - Jeremy L Gilbert
- Clemson - Medical University of South Carolina Bioengineering Program, Department of Bioengineering, Clemson University, Bioengineering Building, 101D, MSC 501, 68 Presidents St, BE 325, Medical University of South Carolina, Charleston, SC 29425.
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BASHA SHAIKAKBAR, SARKAR DEBASISH. COMPETITIVE LIFE TIME ASSESSMENT OF SrO-ZTA/SrO-ZTA AND CoCrMo/UHMWPE HIP PROSTHESIS BEARINGS. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519420500098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hip joint envisages the prime load bearing structure among other joints in the human body. Hip joint failure leads to the replacement of the hip joint prosthesis. This research work focuses on the proper selection of bearing couple materials for the hip joint to improve the performance and life. Herein, the stress and deformation of different bearing couple materials are analysed in the perspective of transient dynamic analysis under jogging load cycle. Selective hip joint bearing (femoral head-liner) couples are SS316L on UHMWPE (MoP), CoCrMo on UHMWPE (MoP), Ti6Al4V on SrO-ZTA (MoC), SrO-ZTA on UHMWPE (CoP) and SrO-ZTA on SrO-ZTA (CoC) encountered, respectively. The SrO-ZTA on SrO-ZTA (CoC) bearing couple generates the less Von Mises stress of 180.88 MPa. Load bearing pressure and Archard law predict the wear depth of CoCrMo on UHMWPE (MoP) and SrO-ZTA on SrO-ZTA (CoC) bearing couples are 0.141 mm/year and 0.031 mm/year, respectively. In simultaneous, the theoretical wear volume for CoCrMo on UHMWPE (MoP) and SrO-ZTA on SrO-ZTA (CoC) bearing couples are found as 35.46[Formula: see text]mm3/year and 2.62[Formula: see text]mm3/year, respectively. The wear depth and wear volume are supporting the available clinical retrievals and exist in well acceptable range. Competitive wear analysis data ensures 15 years safe life of SrO-ZTA on SrO-ZTA (CoC) hip prosthesis bearing.
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Affiliation(s)
- SHAIK AKBAR BASHA
- Department of Ceramic Engineering, National Institute of Technology, Rourkela, India
| | - DEBASISH SARKAR
- Department of Ceramic Engineering, National Institute of Technology, Rourkela, India
- HiLASE, Institute of Physics, ASCR, Prague, Czech Republic
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Wawrose RA, Urish KL. Diagnosis and Management of Adverse Reactions to Metal Debris. OPERATIVE TECHNIQUES IN ORTHOPAEDICS 2019; 29:100732. [PMID: 32296268 PMCID: PMC7158878 DOI: 10.1016/j.oto.2019.100732] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Modern total hip arthroplasty implants have incorporated modularity into their designs, providing the benefits of intraoperative flexibility and the ability to exchange the femoral heads in the future if necessary. However, this feature has unfortunately predisposed patients to the effects of corrosion, potentially resulting in adverse local tissue reactions (ALTR) and even systemic effects. A thorough understanding of the science of corrosion is important for the treating surgeon so that they can understand the underlying pathology, quickly diagnose the condition of ALTR, and risk stratify their patients to determine the best method of treatment. Revision surgery is not always necessary in cases of trunnionosis or ALTR, but the results of revision surgery are generally favorable.
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Affiliation(s)
- Richard A. Wawrose
- Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Suite 1010, Pittsburgh, PA 15213
| | - Kenneth L. Urish
- Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Suite 1010, Pittsburgh, PA 15213
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Urish KL, Giori NJ, Lemons JE, Mihalko WM, Hallab N. Trunnion Corrosion in Total Hip Arthroplasty-Basic Concepts. Orthop Clin North Am 2019; 50:281-288. [PMID: 31084829 PMCID: PMC6521866 DOI: 10.1016/j.ocl.2019.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
There has been increased interest in the role of corrosion in early implant failures and adverse local tissue reaction in total hip arthroplasty. We review the relationship between the different types of corrosion in orthopaedic surgery including uniform, pitting, crevice, and fretting or mechanically assisted crevice corrosion (MACC). Passive layer dynamics serves a critical role in each of these processes. The femoral head-neck trunnion creates an optimal environment for corrosion to occur because of the limited fluid diffusion, acidic environment, and increased bending moment.
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Affiliation(s)
- Kenneth L. Urish
- Corresponding Author: Arthritis and Arthroplasty Design Group, The Bone and Joint Center, Magee Womens Hospital of the University of Pittsburgh Medical Center; Department of Orthopaedic Surgery, Department of Bioengineering, and Clinical and Translational Science Institute, University of Pittsburgh; Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA. .
| | - Nicholas John Giori
- VA Palo Alto Health Care System, Palo Alto, CA and Department of Orthopaedic Surgery, Stanford University, Stanford, CA, 450 Broadway Street, Pavilion C, 4th Floor, Redwood City, CA 94063-6342
| | - Jack E. Lemons
- Department of Orthopaedic Surgery, University of Alabama at Birmingham. Birmingham, AL, 1313 13th Street South, Birmingham, AL 35205-5327
| | - William M. Mihalko
- Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, University of Tennessee Health Science Center, Memphis, TN 1211 Union Avenue, Suite 510, Memphis TN 38104
| | - Nadim Hallab
- Department of Orthopaedic Surgery, Rush University, Chicago, IL 1653 W. Congress Parkway, Chicago, IL 60612
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In vivo electrochemical corrosion study of a CoCrMo biomedical alloy in human synovial fluids. Acta Biomater 2015; 21:228-36. [PMID: 25797841 DOI: 10.1016/j.actbio.2015.03.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 02/09/2015] [Accepted: 03/05/2015] [Indexed: 11/22/2022]
Abstract
The present study was initiated with the aim to assess the in vivo electrochemical corrosion behaviour of CoCrMo biomedical alloys in human synovial fluids in an attempt to identify possible patient or pathology specific effects. For this, electrochemical measurements (open circuit potential OCP, polarization resistance Rp, potentiodynamic polarization curves, electrochemical impedance spectroscopy EIS) were carried out on fluids extracted from patients with different articular pathologies and prosthesis revisions. Those electrochemical measurements could be carried out with outstanding precision and signal stability. The results show that the corrosion behaviour of CoCrMo alloy in synovial fluids not only depends on material reactivity but also on the specific reactions of synovial fluid components, most likely involving reactive oxygen species. In some patients the latter were found to determine the whole cathodic and anodic electrochemical response. Depending on patients, corrosion rates varied significantly between 50 and 750 mg dm(-2)year(-1).
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Cadossi M, Mazzotti A, Baldini N, Giannini S, Savarino L. New couplings, old problems: Is there a role for ceramic-on-metal hip arthroplasty? J Biomed Mater Res B Appl Biomater 2015; 104:204-9. [DOI: 10.1002/jbm.b.33383] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 12/11/2014] [Accepted: 01/22/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Matteo Cadossi
- Department I of Orthopaedics and Traumatology; Rizzoli Orthopaedic Institute; Bologna Italy
- Department of Biomedical and Neuromotor Sciences; Bologna University; Bologna Italy
| | - Antonio Mazzotti
- Department of Biomedical and Neuromotor Sciences; Bologna University; Bologna Italy
| | - Nicola Baldini
- Department of Biomedical and Neuromotor Sciences; Bologna University; Bologna Italy
- Laboratory for Orthopaedic Pathophysiology and Regenerative Medicine; Rizzoli Orthopaedic Institute; Bologna Italy
| | - Sandro Giannini
- Department I of Orthopaedics and Traumatology; Rizzoli Orthopaedic Institute; Bologna Italy
- Department of Biomedical and Neuromotor Sciences; Bologna University; Bologna Italy
| | - Lucia Savarino
- Laboratory for Orthopaedic Pathophysiology and Regenerative Medicine; Rizzoli Orthopaedic Institute; Bologna Italy
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Jakobsen SS, Lidén C, Søballe K, Johansen JD, Menné T, Lundgren L, Bregnbak D, Møller P, Jellesen MS, Thyssen JP. Failure of total hip implants: metals and metal release in 52 cases. Contact Dermatitis 2014; 71:319-25. [PMID: 25041132 DOI: 10.1111/cod.12275] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/14/2014] [Accepted: 05/20/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. OBJECTIVES To assess cobalt, nickel and chromium(VI) release from, and the metal composition of, failed metal-on-ethylene total hip replacements. MATERIALS/METHODS Implant components from 52 revision cases were evaluated with spot tests for free nickel, cobalt, and chromium (VI) ions. Implant composition was determined with X-ray fluorescence spectroscopy, and information on the reason for revision and complications in relation to surgery was collected from the medical charts when possible (72%). For 10 implants, corrosion was further characterized with scanning electron microscopy. RESULTS We detected cobalt release from three of 38 removed femoral heads and from one of 24 femoral stems. Nickel release was detected from one of 24 femoral stems. No chromium(VI) release was detected. CONCLUSIONS We found that cobalt and nickel were released from some failed total hip arthroplasties, and corrosion was frequently observed. Metal ions and particles corroded from metal-on-polyethylene may play a role in the complex aetiopathology of implant failure.
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Affiliation(s)
- Stig S Jakobsen
- Department of Orthopaedic Surgery, Aarhus University Hospital, DK-8000, Aarhus, Denmark
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Hedberg YS, Qian B, Shen Z, Virtanen S, Wallinder IO. In vitro biocompatibility of CoCrMo dental alloys fabricated by selective laser melting. Dent Mater 2014; 30:525-34. [PMID: 24598762 DOI: 10.1016/j.dental.2014.02.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/13/2014] [Accepted: 02/12/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Selective laser melting (SLM) is increasingly used for the fabrication of customized dental components made of metal alloys such as CoCrMo. The main aim of the present study is to elucidate the influence of the non-equilibrium microstructure obtained by SLM on corrosion susceptibility and extent of metal release (measure of biocompatibility). METHODS A multi-analytical approach has been employed by combining microscopic and bulk compositional tools with electrochemical techniques and chemical analyses of metals in biologically relevant fluids for three differently SLM fabricated CoCrMo alloys and one cast CoCrMo alloy used for comparison. RESULTS Rapid cooling and strong temperature gradients during laser melting resulted in the formation of a fine cellular structure with cell boundaries enriched in Mo (Co depleted), and suppression of carbide precipitation and formation of a martensitic ɛ (hcp) phase at the surface. These features were shown to decrease the corrosion and metal release susceptibility of the SLM alloys compared with the cast alloy. Unique textures formed in the pattern of the melting pools of the three different laser melted CoCrMo alloys predominantly explain observed small, though significant, differences. The susceptibility for corrosion and metal release increased with an increased number (area) of laser melt pool boundaries. SIGNIFICANCE This study shows that integrative and interdisciplinary studies of microstructural characteristics, corrosion, and metal release are essential to assess and consider during the design and fabrication of CoCrMo dental components of optimal biocompatibility. The reason is that the extent of metal release from CoCrMo is dependent on fabrication procedures.
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Affiliation(s)
- Yolanda S Hedberg
- Institute of Surface Science and Corrosion, Department of Materials Science and Engineering 4, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany; KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas väg 51, 10044 Stockholm, Sweden.
| | - Bin Qian
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Zhijian Shen
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Sannakaisa Virtanen
- Institute of Surface Science and Corrosion, Department of Materials Science and Engineering 4, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany
| | - Inger Odnevall Wallinder
- KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas väg 51, 10044 Stockholm, Sweden
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Hesketh J, Ward M, Dowson D, Neville A. The composition of tribofilms produced on metal-on-metal hip bearings. Biomaterials 2014; 35:2113-9. [DOI: 10.1016/j.biomaterials.2013.11.065] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/21/2013] [Indexed: 12/12/2022]
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Savarino L, Cadossi M, Chiarello E, Baldini N, Giannini S. Do ion levels in metal-on-metal hip resurfacing differ from those in metal-on-metal THA at long-term followup? Clin Orthop Relat Res 2013; 471:2964-71. [PMID: 23572350 PMCID: PMC3734417 DOI: 10.1007/s11999-013-2981-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 04/02/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND Metal-on-metal hip resurfacing arthroplasty (MOM HR) has become an established alternative to traditional metal-on-metal total hip arthroplasty (MOM THA) for younger, more active patients. Nevertheless, concerns remain regarding wear and corrosion of the bearing surfaces and the resulting systemic metal ion distribution. QUESTIONS/PURPOSES We therefore asked whether (1) serum ion concentrations in patients with MOM HR at the time of long-term followup were higher than concentrations in a control population with no hip implants; (2) the ion concentrations in patients with MOM HR were different from those in patients with MOM THA; and (3) sex would influence ion levels with regard to implant type. METHODS The MOM HR and MOM THA groups consisted of 25 patients (evaluated at a minimum of 96 months) and 16 patients (evaluated at a minimum of 106 months), respectively. Forty-eight healthy donors were recruited for reference values. Cobalt, chromium, nickel, and molybdenum were measured by furnace graphite atomic absorption spectrophotometry. RESULTS Ion concentrations of cobalt, chromium, and molybdenum in MOM HR were higher than in controls. Chromium and cobalt release were higher in MOM HR than in MOM THA. The sex-based analysis showed the difference was because women had higher concentrations in the MOM HR group than in the MOM THA group, whereas there was no difference between the men in the two groups. CONCLUSIONS In MOM HR, high metal ion release persists for the long term. Consequently, it is important to implement strict biomonitoring for patients who have received these implants. The sustained high levels of chromium in females within the MOM HR group are concerning and merits strong consideration when choosing implants in this patient group.
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Affiliation(s)
- Lucia Savarino
- Laboratory for Orthopaedic Pathophysiology and Regenerative Medicine, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy
| | - Matteo Cadossi
- Department I of Orthopaedics and Traumatology, Rizzoli Orthopaedic Institute, Bologna, Italy
| | - Eugenio Chiarello
- Department I of Orthopaedics and Traumatology, Rizzoli Orthopaedic Institute, Bologna, Italy
| | - Nicola Baldini
- Laboratory for Orthopaedic Pathophysiology and Regenerative Medicine, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy ,Bologna University, Bologna, Italy
| | - Sandro Giannini
- Department I of Orthopaedics and Traumatology, Rizzoli Orthopaedic Institute, Bologna, Italy ,Bologna University, Bologna, Italy
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In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators. J Mech Behav Biomed Mater 2012. [PMID: 23182693 DOI: 10.1016/j.jmbbm.2012.08.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces.
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Rudol G, Wilcox R, Jin Z, Tsiridis E. The effect of surface finish and interstitial fluid on the cement-in-cement interface in revision surgery of the hip. ACTA ACUST UNITED AC 2011; 93:188-93. [DOI: 10.1302/0301-620x.93b2.24759] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The mechanical performance of the cement-in-cement interface in revision surgery has not been fully investigated. The quantitative effect posed by interstitial fluids and roughening of the primary mantle remains unclear. We have analysed the strength of the bilaminar cement-bone interface after exposure of the surface of the primary mantle to roughening and fluid interference. The end surfaces of cylindrical blocks of cement were machined smooth (Ra = 200 nm) or rough (Ra = 5 μm) and exposed to either different volumes of water and carboxymethylcellulose (a bone-marrow equivalent) or left dry. Secondary blocks were cast against the modelled surface. Monoblocks of cement were used as a control group. The porosity of the samples was investigated using micro-CT. Samples were exposed to a single shearing force to failure. The mean failure load of the monoblock control was 5.63 kN (95% confidence interval (CI) 5.17 to 6.08) with an estimated shear strength of 36 MPa. When small volumes of any fluid or large volumes were used, the respective values fell between 4.66 kN and 4.84 kN with no significant difference irrespective of roughening (p > 0.05). Large volumes of carboxymethylcellulose significantly weakened the interface. Roughening in this group significantly increased the strength with failure loads of 2.80 kN (95% CI 2.37 to 3.21) compared with 0.86 kN (95% CI 0.43 to 1.27) in the smooth variant. Roughening of the primary mantle may not therefore be as crucial as has been previously thought in clinically relevant circumstances.
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Affiliation(s)
- G. Rudol
- Department of Trauma and Orthopaedics, Leeds General Infirmary, Clarendon A, Great George Street, Leeds LS1 3EX, UK
| | - R. Wilcox
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds, Leeds LS2 9JT, UK
| | - Z. Jin
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds, Leeds LS2 9JT, UK
| | - E. Tsiridis
- University of Thessaloniki, University Campus GR 54124, Thessaloniki, Greece
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Valero Vidal C, Olmo Juan A, Igual Muñoz A. Adsorption of bovine serum albumin on CoCrMo surface: effect of temperature and protein concentration. Colloids Surf B Biointerfaces 2010; 80:1-11. [PMID: 20554436 DOI: 10.1016/j.colsurfb.2010.05.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 05/03/2010] [Accepted: 05/03/2010] [Indexed: 12/01/2022]
Abstract
The adsorption of bovine serum albumin (BSA) onto CoCrMo surface has been studied as a function of concentration of BSA and temperature by electrochemical techniques. The electrochemical impedance spectroscopy (EIS) technique was used to investigate the interfacial behaviour of BSA at open circuit potential (OCP). The charge transfer resistance was very sensitive to the amount of adsorbed protein, indicating that the adsorption process was accompanied by the transfer of charge and influenced the mechanism and kinetics of the corrosion reaction. At all the temperatures studied, adsorption of BSA onto the CoCrMo surface was successfully described with a Langmuir adsorption isotherm. EIS study was also carried out for determine the surface charge density, resulting from protein adsorption, and it was shown to be directly proportional to the amount of adsorbed protein (surface concentration). Thermodynamic data of adsorption was obtained for analyzing the adsorption of BSA onto CoCrMo surface. Gibbs free energy of adsorption, DeltaG(ADS) values, for BSA in the investigated temperature range (-51kJmol(-1)) showed that the molecules have a strong affinity for the CoCrMo surface. Enthalpy (DeltaH(ADS)) and entropy (DeltaS(ADS)) of adsorption suggested that the adsorption process of BSA onto the CoCrMo surface is an endothermic process and the molecule suffers structural changes when adsorbing on the metallic surface.
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Affiliation(s)
- C Valero Vidal
- Departamento de Ingeniería Química y Nuclear, E.T.S.I. Industriales, Universidad Politécnica de Valencia, P.O. Box 22012, E-46071 Valencia, Spain
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Ouerd A, Alemany-Dumont C, Normand B, Szunerits S. Reactivity of CoCrMo alloy in physiological medium: Electrochemical characterization of the metal/protein interface. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.01.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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