Blood Metal Ion Concentrations Research Articles

The Withdrawn ASR™ THA and Hip Resurfacing Systems: How Have Our Patients Fared Over 1 to 6 Years?

The Articular Surface Replacement™ (ASR™) metal-on-metal hip arthroplasty system (DePuy Orthopaedics, Inc, Warsaw, IN, USA) reportedly has a higher than anticipated early failure rate leading to a voluntary recall. This prompted us to evaluate all ASR™ components implanted at our center. In all ASR™ components, we reported (1) revision rate, (2) blood metal ion levels, and (3) intraoperative findings for revisions related to adverse reaction to metal debris (ARMD). We retrospectively reviewed all 172 patients (190 hips) who underwent THA (149 hips) or hip resurfacing (41 hips) with the ASR™ system. We determined failure rates. We obtained blood metal ion concentrations from 93 patients at last followup. We evaluated MRI studies and intraoperative histopathology. Minimum followup was 12months (mean, 40months; range, 12-74months). At latest followup, we had revised 24 of 190 hips (13%): in 18 patients with THA and five patients with resurfacing. Mean time to revision was 45months (range, 12-75months). Mean blood concentrations were 13μg/L (range, 0-150μg/L) for cobalt and 6μg/L (range, 0-87μg/L) for chromium. Mean prerevision blood metal ion levels were higher in the revised group (cobalt: 48μg/L; chromium: 18μg/L) than in the nonrevised group (cobalt: 5μg/L; chromium: 2μg/L). ARMD was present in 14 of the 24 hips revised in this study. Surgeons must have a low threshold for concern for ARMD in patients with ASR™ systems. Blood metal ion levels and MRI can be used to evaluate patients with underperforming implants. Intraoperative histopathologic analysis and joint fluid cytology can help diagnose ARMD at the time of revision. Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

An analysis of metal ion levels in the joint fluid of symptomatic patients with metal-on-metal hip replacements

We retrospectively analysed concentrations of chromium and cobalt ions in samples of synovial fluid and whole blood taken from a group of 92 patients with failed current-generation metal-on-metal hip replacements. We applied acid oxidative digestion to our trace metal analysis protocol, which found significantly higher levels of metal ion concentrations in blood and synovial fluid than a non-digestive method. Patients were subcategorised by mode of failure as either 'unexplained pain' or 'defined causes'. Using this classification, chromium and cobalt ion levels were present over a wider range in synovial fluid and not as strongly correlated with blood ion levels as previously reported. There was no significant difference between metal ion concentrations and manufacturer of the implant, nor femoral head size below or above 50 mm. There was a moderately positive correlation between metal ion levels and acetabular component inclination angle as measured on three-dimensional CT imaging. Our results suggest that acid digestion of samples of synovial fluid samples is necessary to determine metal ion concentrations accurately so that meaningful comparisons can be made between studies.

Blood metal ion concentrations after hip resurfacing arthroplasty: A comparative study of articular surface replacement and Birmingham Hip Resurfacing arthroplasties

Blood metal ion concentrations after hip resurfacing arthroplasty: A comparative study of articular surface replacement and Birmingham Hip Resurfacing arthroplasties

Bioavailability of aluminum from drinking water

Aluminum, present in our drinking water as hydroxide or sulfate, is limited by solubility to 2.5 mg/liter at pH 7.0. This study was carried out to determine if aluminum at doses typically found in drinking water would accumulate in rat tissues if a ligand such as citrate at neutral or acid pH is coadministered, or in the absence of citrate at acid pH. Al(OH) 3 or AlCl 3 was given ad libitum in drinking water to male Sprague-Dawley rats at 0, 0.1, 2.0, or 100 mg/liter, in 4 m m acetate, pH 3.2 (A), 4 m m citrate, pH 2.6 (C), 4 m m citrate, pH 7.0 (7C), or distilled water, pH 7.0 (W). After 10 weeks, rats were killed and tissues were wet-ashed in nitric acid for determination of aluminum by flameless atomic absorption. Copper, iron, and zinc were determined by flame atomic absorption. Metal ion concentrations in tibia, brain, liver, blood, and kidney did not differ significantly between treatment groups. Aluminum accumulated in intestinal cells of all 100 mg Al/liter rats, with the C group accumulating more aluminum than the A or W groups. In the C group, intestinal aluminum content increased significantly in a dose-dependent manner. Intestinal iron was decreased significantly in all the 100 mg Al/liter groups. Intestinal copper was decreased in the W group at 100 mg Al/liter, with a trend toward a decrease in A and C groups. We conclude that at these low levels studied, aluminum accumulates in intestinal tissue, and that this accumulation is enhanced by citrate ligand. At 100 mg Al/liter, intestinal iron accumulation is decreased, and copper accumulation is marginally decreased.

Bioavailability of Aluminum from Drinking Water

Bioavailability of Aluminum from Drinking Water. FULTON, B., JAW, S., AND JEFFERY, E. H. (1989). Fundam Appl. Toxicol. 12, 144–150. Aluminum, present in our drinking water as hydroxide or sulfate, is limited by solubility to 2.5 mg/liter at pH 7.0. This study was carried out to determine if aluminum at doses typically found in drinking water would accumulate in rat tissues if a ligand such as citrate at neutral or acid pH is coadministered, or in the absence of citrate at acid pH. Al(OH)3 or AlCl3 was given ad libitum in drinking water to male Sprague-Dawley rats at 0, 0.1, 2.0, or 100 mg/liter, in 4 mM acetate, pH 3.2 (A), 4 mM citrate, pH 2.6 (C), 4 mM citrate, pH 7.0 (7C), or distilled water, pH 7.0(W). After 10 weeks, rats were killed and tissues were wet-ashed in nitric acid for determination of aluminum by flameless atomic absorption. Copper, iron, and zinc were determined by flame atomic absorption. Metal ion concentrations in tibia, brain, liver, blood, and kidney did not differ significantly between treatment groups. Aluminum accumulated in intestinal cells of all 100 mg Al/liter rats, with the C group accumulating more aluminum than the A or W groups. In the C group, intestinal aluminum content increased significantly in a dose-dependent manner. Intestinal iron was decreased significantly in all the 100 mg Al/liter groups. Intestinal copper was decreased in the W group at 100 mg Al/liter, with a trend toward a decrease in A and C groups. We conclude that at these low levels studied, aluminum accumulates in intestinal tissue, and that this accumulation is enhanced by citrate ligand. At 100 mg Al/liter, intestinal iron accumulation is decreased, and copper accumulation is marginally decreased.