Analysis of hematological metal element levels in orthopedic patients with implants

Background: The progressive increase in concentration of circulating metal by-products derived from the metal-based orthopedic implants may have deleterious effects in the patients over the long term. Therefore, it is necessary to profile the metal levels in the body of the patients receiving metal implants using appropriate highly sensitive techniques and strategies. Hence, in this study, we estimated the levels of metal in serum of patients with metal implants. Materials and Methods: Blood samples of 25 patients with metallic implants were collected at 6 months postsurgery. The blood samples were subjected to triple acid digestion and then analyzed through inductively coupled plasma–mass spectroscopy, and the blood levels of various metals were quantified. Results: An increase in serum levels of titanium was observed in the patients with metal implants at 6 months postsurgical implant. However, the levels of titanium were within the normal range (normal level <7.2 μg/l), and we did not observe any signs of detectable systemic toxicity. In contrast, the mean serum levels of cobalt (0.19–2.6 μg/l) and nickel (0.05–1.08 μg/l) were above the normal range. Conclusion: Orthopedic patients with metal implants had the serum levels of titanium within the normal range but had serum levels of cobalt and nickel above the normal range. Despite increase in the serum levels of cobalt and nickel, the patients did not show any clinical signs of toxicity.