gms | German Medical Science

Objectives: Arthroplasty-associated metal exposure has been linked to systemic toxicity. Neurological, cardiac and thyroid dysfunctions following cobalt-chromium exposure due to implant wear and corrosion have been reported most commonly. Moreover, potential immunotoxicity, cancerogenicity and teratogenicity of cobalt and chromium species, but also of all other metals released from joint prostheses, have become a focal point of interest. However, evidence of systemic distribution of these 'arthroplasty metals', as a prerequisite for any proclaimed systemic effect, is largely missing. Whether, to what extent and in which form these metals enter the patient's blood may be identified by multi-element analysis. We aimed to provide a preliminary assessment regarding the systemic levels of all arthroplasty-relevant metals in patients who have a history of hip and/or knee joint replacement.

Methods: As part of our institution's diagnostic standard, whole blood multi-element analyses (MEA) were conducted for any patient of any sex and age who underwent elective revision total hip or knee replacement at our institution between 06/2018 and 09/2019. MEA were performed with inductively coupled plasma mass spectrometry (ICP-MS) and included quantification of concentrations of aluminum, cobalt, chromium, molybdenum, nickel, niobium, tantalum, titanium, vanadium and zirconium. Demographic and implant-related data were collected retrospectively by chart-review. Considering this analysis' explorative character, statistics were limited to descriptive analyses.

Results: MEA of whole blood of 118 patients who underwent revision hip or knee replacement were included in this study; the results are summarized in Table 1. We found that in 58% (68/118) of these patients the blood level of at least one arthroplasty metal was above normal. We learned that in patients with elevated systemic cobalt concentrations chromium levels were also always raised, that systemic titanium levels might rise by several magnitudes, elevated niobium and vanadium levels only occurred in patients in whom titanium was also significantly elevated, and that cement leakage into periprosthetic soft tissues was associated with elevated systemic concentrations of zirconium. MEA did not detect any significantly elevated aluminum concentration in any of the patients included.

Conclusion: Multi-element analyses of whole blood provide information on whether and to what extent systemic metal levels rise in people who underwent arthroplasty. Their results may compliment and facilitate differential diagnostics of new-onset symptoms and diseases potentially affecting different organ systems in the aftermath of joint replacement.