Clarke IC: Metal-on-metal bearing in hip prosthesis generates 100 ..
The metal content was measured in different areas of the periprosthetic tissues. The tissues were sampled at the time of surgery from the bursa, the capsule, from the proximal femur, and behind the acetabular cup after implant removal. Tissues were then fixed in 5% formalin. All tissues were dried at 55°C to constant weight followed by chemical digestion with 65% nitric acid and 30% hydrogen peroxide in a microwave oven (EN 13805:2002). This treatment does not modulate the amount of metal content of the tissue. The dissolved tissues were analyzed by inductively coupled plasma optical emission spectrometry (EN ISO 11885:2009) for cobalt (Co), chromium (Cr), nickel (Ni), molybdenum (Mo), titanium (Ti), and iron (Fe). The detection limit for Co is 25 ng/g, Ni 25 ng/g, Mo 20 ng/g, Ti 15 ng/g, Cr 5 ng/g, and Fe 2.5 ng/g. The results were then normalized per grams of tissue. Additionally, results of Ti determination were audited by Zeemann graphite-furnace AAS (Varian Z880).
for use in a metal-on-metal hip prosthesis.
To confirm the metallurgy of the implant materials and to prepare for the electrochemical inspection, the CLS-Spotorno stem and LDH Metasul adapter were analyzed by x-ray fluorescence. For evidence of electrochemical reaction between the stem and adapter, a minicell electrode was made by using platinum wire. The open circuit potential was measured against the reference system SE 11 (Ag/AgCl sat. reference system, Meinsberg).
We therefore determined: (1) if corrosion occurred at the cone/taper interface leading to instability in patients with revised large-diameter THAs; (2) how patients presented clinically and radiographically; (3) if an adverse reactions to the metallic debris occurred; (4) if the metal released from the implant components was retained in periprosthetic tissues; and (5) if head size correlated with metal release from the unstable cone/taper interfaces.