“…The most common orthopaedic soluble metal (ions) sensitizers include nickel, Ni, [16,23,30,35] cobalt, Co, [35] and chromium, Cr, [35] while occasional responses have been reported to tantalum, Ta, [ 11 titanium, Ti, [33,43] and vanadium, V [l]. Nickel is the most common metal sensitizer in humans followed by Co and Cr [2,16,23,30] and cross reactivity between Ni and Co is common [2]. The incidence of metal sensitivity among the general population is approximately 10% and among patients with well functioning and poorly functioning implants is approximately 25% and 6O%, respectively, in reported compiled analyses of numerous investigations [ 191. What remained poorly characterized were the specific metals that mediate implant related metal hypersensitivity reactions, the incidence of THA metal hypersensitivity using modern immunological testing methods and the relation of metal hypersensitivity to implant performance.…”