The toxicity of metals used in orthopaedic prostheses. An experimental study using cultured human synovial fibroblasts

Abstract

Some ofthe component metals ofthe alloys used for totaljoint prostheses are toxic and dissolve in the body fluids. It is important to establish how toxic these metals are and to assess the risk oflocalised tissue necrosis around the prostheses. This has been investigated by incubating primary monolayer cultures of human synovial fibroblasts with various preparations of metals for periods up to 18 days. Morphological changes were evident after exposure to cobalt chloride at a concentration of 50 nanomoles per mililitre and to nickel chloride at 200 nanomoles per millilitre. Chromic chloride, ammonium molybdate and ferric chloride produced no changes up to 500 nanomoles per mililitre. Cultures exposed to particulate pure metals were poisoned by cobalt and vanadium but were not affected under the same conditions by nickel, chromium, molybdenum, titanium or aluminium. Particulate cobalt and vanadium were probably toxic due to their relatively high solubility (four and one micromoles per millilitre respectively after seven days incubation). Particulate nickel also dissolved (three nanomoles per millilitre after seven days) but not in sufficient quantities to be toxic. It appears, therefore, that potentially the most harmful components are cobalt from cobaltchromium alloy, nickel from stainless steel, and vanadium from titanium alloy. As far as can be estimated, the only combination of materials which is likely to give rise to toxic levels of metal under clinical conditions, is cobalt-chromium alloy articulating against itselfto produce relatively high levels of cobalt.

Nickel-free austenitic stainless steels for medical applications

“…These factors probably lead to an early fracture or failure of the implants, and corrosion of the implanted devices may result in release of harmful products into the body [4][5][6]. Finally, the most important problem is the negative effect of metal ions or fretting debris [6][7][8][9][10][11], which can be released from the stainless steel implant devices because of corrosion, wear or other reasons. Nickel and chromium are known as potentially harmful elements in the medical stainless steel [7,11].…”

“…Finally, the most important problem is the negative effect of metal ions or fretting debris [6][7][8][9][10][11], which can be released from the stainless steel implant devices because of corrosion, wear or other reasons. Nickel and chromium are known as potentially harmful elements in the medical stainless steel [7,11]. Nickel ions act as the allergens, which may cause cutaneous inflammations such as swelling, reddening, eczema and itching on skins, and may also lead to allergy reactions, teratogenicity and carcinogenicity in human body [10][11][12][13][14][15][16][17][18][19][20].…”

“…Nickel and chromium are known as potentially harmful elements in the medical stainless steel [7,11]. Nickel ions act as the allergens, which may cause cutaneous inflammations such as swelling, reddening, eczema and itching on skins, and may also lead to allergy reactions, teratogenicity and carcinogenicity in human body [10][11][12][13][14][15][16][17][18][19][20].…”

Surface analysis of a femoral stem after failed total hip replacement

“…The high resistance to corrosion in a physiological environment is related to the formation of a passive oxide layer on the surface of the implant. Titanium, titanium alloys and titanium dioxide show little toxicity [1,5] : the in vitro toxicity is dependent on several factors, such as size, shape and impurity content [4]. However, Willert et al [6] reported the models of corrosion which could develop on the surface of Ti loosened cemented stems, which were pitting associated with abrasion of the cement, and crevice corrosion caused by depletion of oxygen at the implant-cement interface, which reduces the formation of the surface layer.…”

Cytocompatibility Evaluation of Ti-Ni and Ti-Mo-Al System Shape Memory Alloys

“…It is also proved that the results of the cytotoxicity evaluation correlate well to the levels of inflammation observed by in vivo implantation tests. 19) Cytotoxicity evaluation has been performed for the specimens of pure metals and alloys, [20][21][22][23][24] metal salts, [25][26][27][28] particulate metals, [29][30][31][32] and metallic debris. 33,34) In this study, the cytocompatibility of newly developed nickel-free shape memory alloys, Ti-Mo-Al, is evaluated using human normal diploid fibroblasts in static and dynamic conditions, comparing with that of a conventional Ti-Ni shape memory alloy.…”