Effect of carbon content on the resistance to localized corrosion of as‐cast cobalt‐based alloys in an aqueous chloride solution

Montero‐Ocampo, C.; Salinas‐Rodríguez, Armando

doi:10.1002/jbm.820290404

Cited by 29 publications

(14 citation statements)

References 9 publications

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“…A problem with enhanced carbide levels is a reduction in corrosion resistance. 25 This may potentially account for the low levels of metal ions observed in patients with the Ultima MOM THA manufactured from wrought CoCrMo with a low carbon content in the femoral head.…”

Section: Discussionmentioning

confidence: 99%

Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty

Clarke

Lee

Arora

et al. 2003

The Journal of Bone and Joint Surgery. British volume

221

130

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etal-on-metal (MOM) bearings for hip arthroplasty are increasing in popularity. Concern remains, however, regarding the potential toxicological effects of the metal ions which these bearings release.The serum levels of cobalt and chromium in 22 patients who had undergone MOM resurfacing arthroplasty were compared with a matched group of 22 patients who had undergone 28 mm MOM total hip arthroplasty (THA).At a median of 16 months (7 to 56) after resurfacing arthroplasty, we found the median serum levels of cobalt and chromium to be 38 nmol/l (14 to 44) and 53 nmol/l (23 to 165) respectively. These were significantly greater than the levels after 28 mm MOM THA which were 22 nmol/l (15 to 87, p = 0.021) and 19 nmol/l (2 to 58, p < 0.001) respectively.Since the upper limit for normal patients without implants is typically 5 nmol/l, both groups had significantly raised levels of metal ions. MOM bearings of large diameter, however, result in a greater systemic exposure of cobalt and chromium ions than bearings of small diameter. This may be of relevance for potential long-term side-effects. It is not known to what extent this difference is due to corrosion of the surfaces of the component or of the wear particles produced. MMetal-on-metal (MOM) bearings were first used in total hip arthroplasty (THA) over 40 years ago.1-3 Because of a limited understanding of the engineering of these bearings and early failures in some cases, they lost popularity to the lowfriction stainless-steel/ultra-high-molecular-weight polyethylene bearing developed by Charnley. 4 Over the past 15 years, with an improved understanding of the aetiology of aseptic loosening and of the science of wear, there has been increased interest in the use of MOM bearings. 5,6 Of the many engineering factors which have contributed to the success of the MOM bearing, the metallurgy, diametric bearing clearance, sphericity and surface finish are thought to be most important. 7-9All metal implants, especially those which include MOM bearings corrode at a rate determined, in part, by their surface area. 10 Further, side-effects relate directly to the particles of metal which are produced and their subsequent fate within the body. Our hypothesis was that the production of wear debris, and thus metal ion release, would be less after resurfacing arthroplasty than after THA using a 28 mm MOM bearing. This was based on the theoretical fluid film lubrication and reduced potential for the production of wear debris which is thought to occur in MOM bearings of large diameter, despite the increased surface area available for corrosion with these implants. 11 Patients and MethodsEvaluation of patients. All joint arthroplasties are prospectively registered on a computerised database. We contacted patients who had undergone either unilateral MOM or resurfacing arthroplasty at least six months earlier and asked them to attend dedicated clinics. They completed a questionnaire and provided a sample of blood for analysis of cobalt and chromium. Since we were interested in estima...

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Section: Discussionmentioning

confidence: 99%

Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty

Clarke

Lee

Arora

et al. 2003

The Journal of Bone and Joint Surgery. British volume

221

130

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“…3 Montero-Ocampa and Rodriguez 4 correlated pitting corrosion to carbon content of the CoCrMo alloy.…”

Section: Introductionmentioning

confidence: 98%

Effect of synovial fluid, phosphate‐buffered saline solution, and water on the dissolution and corrosion properties of CoCrMo alloys as used in orthopedic implants

Lewis

Kilburn

Papageorgiou

et al. 2005

J Biomedical Materials Res

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The corrosion and dissolution of high- and low-carbon CoCrMo alloys, as used in orthopedic joint replacements, were studied by immersing samples in phosphate-buffered saline (PBS), water, and synovial fluid at 37 degrees C for up to 35 days. Bulk properties were analyzed with a fine ion beam microscope. Surface analyses by X-ray photoelectron spectroscopy and Auger electron spectroscopy showed surprisingly that synovial fluid produced a thin oxide/hydroxide layer. Release of ions into solution from the alloy also followed an unexpected pattern where synovial fluid, of all the samples, had the highest Cr concentration but the lowest Co concentration. The presence of carbide inclusions in the alloy did not affect the corrosion or the dissolution mechanisms, although the carbides were a significant feature on the metal surface. Only one mechanism was recognized as controlling the thickness of the oxide/hydroxide interface. The analysis of the dissolved metal showed two mechanisms at work: (1) a protein film caused ligand-induced dissolution, increasing the Cr concentration in synovial fluid, and was explained by the equilibrium constants; (2) corrosion at the interface increased the Co in PBS. The effect of prepassivating the samples (ASTM F-86-01) did not always have the desired effect of reducing dissolution. The release of Cr into PBS increased after prepassivation. The metal-synovial fluid interface did not contain calcium phosphate as a deposit, typically found where samples are exposed to calcium rich bodily fluids.

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“…Also Wang et al (1999) concluded that wear resistance of the couple as-cast Co-Cr on as-cast Co-Cr alloy was superior to the high carbon wrought on the high carbon wrought couple tested. The effect of carbon content on the corrosion resistance of Co-Cr-Mo ASTM-F75 was studied by Montero-Ocampo and Salinas (1995). They studied alloys containing 0.07, 0.15 and 0.28 wt.% C, within the specifications of the ASTM-F75 standard.…”

Section: Introductionmentioning

confidence: 99%

Cooling rate and carbon content effect on the fraction of secondary phases precipitate in as-cast microstructure of ASTM F75 alloy

Ramírez-Vidaurri

Castro‐Román

Herrera-Trejo

et al. 2009

Journal of Materials Processing Technology

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Effect of carbon content on the resistance to localized corrosion of as‐cast cobalt‐based alloys in an aqueous chloride solution

Cited by 29 publications

References 9 publications

Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty

Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty

Effect of synovial fluid, phosphate‐buffered saline solution, and water on the dissolution and corrosion properties of CoCrMo alloys as used in orthopedic implants

Cooling rate and carbon content effect on the fraction of secondary phases precipitate in as-cast microstructure of ASTM F75 alloy

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