gms | German Medical Science

Objectives: Arthroprosthetic metal exposure has been linked to new-onset neurological dysfunctions. Evidence of systemic distribution of all so-called arthroplasty metals including respective concentrations in cerebrospinal fluid (CSF) is largely missing. Whether and to what extent arthroplasty metals may pass neural barriers may be identified by multi-element analyses (MEA). We aimed at providing an assessment regarding CSF, whole blood and serum levels of all arthroplasty-relevant metals in patients who have a history of large joint replacement versus arthroplasty-naïve controls.

Methods: This prospective single-center observational study was approved by the local ethics committee and prospectively registered (DRKS00014555/6). CSF and blood of patients with at least one large joint replacement in situ (implant group) and of age- and sex- matched arthroplasty-naïve patients (control group) were sampled in the course of routine spinal anesthesia or lumbar puncture. MEA were performed using inductively coupled plasma mass spectrometry and included quantification of Al, Co, Cr, Mo, Ni, Nb, Ta, Ti, V and Zr. Basic demographic, general health and orthopedic history data were collected. The Shapiro-Wilk test, Spearman correlation analysis, Wilcoxon matched-pairs signed rank test, Mann Whitney test and Fisher’s exact test were applied as appropriate. Statistical significance was set at P<0.05.

Results: 204 patients (118 women, 86 men; median age 69.4 years) were included, 102 with arthroplasty implant/s and 102 controls. The two groups did not differ significantly regarding basic demographics. Whole blood analyses demonstrated significantly higher levels of Co, Cr, Ti, Nb, Ta and Zr in the implant group. Serum analyses showed significantly higher levels of Co, Cr, Ni, Ti, V, Nb and Zr in the implant group. In CSF, Co levels were significantly higher in patients of the implant group. Co levels in CSF were significantly correlated with Co levels in serum and whole blood. Patients of the implant group with elevated Co levels in whole blood or serum exhibited significantly higher Co levels in CSF as compared to matched controls. Patients of the implant group with elevated Ti, Nb and Zr levels in serum were found to have significantly higher levels of Ti, Nb and Zr in CSF than matched controls.

Conclusion: Patients with arthroplasty implant/s are systematically exposed to multiple arthroplasty metals. Chronic exposure to arthroprosthetic wear and corrosion products contributes to metal accumulation in CSF. We showed that Co, Ti, Nb and Zr released from arthroplasty implants may cross the blood-central nervous system barriers and significantly accumulate in CSF. Merely Co levels were found to be significantly correlated between blood and CSF, suggesting specific cellular transport. Especially in view of the previously described neurotoxic potential of Co this should be considered particularly in patients with new-onset neurological or psychiatric disorders following arthroplasty.