Metals derived from implants found in cerebrospinal fluid

Research carried out by charity – University Berlin has noted that the metallic particles of artificial joint implants can enter the central nervous system and accumulate in cerebrospinal fluid, which raises concerns concerning potential neurological effects.

Joint replacement surgery has transformed orthopedic care, improving mobility and quality of life for millions of people. Modern implants, made from metal combinations, are designed for sustainability and biocompatibility.

Over time, wear and corrosion of these materials can release microscopic particles in the surrounding tissues. These by-products have been linked to problems near the implant site, including inflammation, tissue lesions and the joint relaxation.

Emerging concerns indicate the possibility that the metallic particles entering the blood circulation and affecting the organs far from the implant. Case relationships have described serious effects on the heart, the thyroid and the nervous system in patients with high levels of certain metals, in particular cobalt and chrome. Neurological changes have been reported in some patients after joint replacement.

Previous research has largely focused on these two metals and relied on blood and serum measurements, leaving the question of whether these particles reach the central nervous system.

In the study, “metallic concentrations in the blood and cerebrospinal fluid of patients with arthroplasty implants”, published in Jama Network OpenThe researchers conducted a single site transversal study to determine whether metals from joint implants can be found in cerebrospinal fluid and blood circulation.

A cohort was estimated by 204 adult participants, 102 with a large existing spouse implant (median age of 71.7) and 102 in a control group which had never undergone joint replacement surgery (67.2 years median).

Samples were taken during elective surgery under vertebral anesthesia or during lumbar puncture for routine diagnostic or therapeutic reasons. The plasma mass spectrometry with inductive coupling has measured the concentrations of ten metals in the blood, serum and cerebrospinal fluid, including cobalt, chrome, titanium, niobium, zirconium and others known to be used in implant materials.

Cobalt levels in cerebrospinal fluid were significantly higher in patients with joint implants than in paired witnesses. Cobalt median concentrations were 0.03 μg / L in the implant group and 0.02 μg / L in the control group. Strong correlations have been observed between cobalt levels in cerebrospinal fluid and those of serum and total blood, which suggests that systemic exposure can reach the central nervous system.

Patients with implants also had higher levels of chrome, titanium, niobium and zirconium in blood and serum. In the cerebrospinal fluid, titanium, niobium and zirconium were significantly high, but only when the serum rates of these metals also increased. This is an important observation because it supports the accuracy of a less invasive blood sampling as an indicator of a possible flood of the cerebrospinal fluid.

Patients with implant components containing cobal-chrome-molybdenum alloys had the highest cerebrospinal fluid concentrations of cobalt and chrome. Cobalt levels in cerebrospinal fluid were significantly high, even in patients with implants in place for less than ten years. The pain in the joint containing the implant was also associated with higher cobalt levels in cerebrospinal fluid.

No increase in cerebrospinal metal levels was observed in patients with implants without cobal-cholyben components. Patients with cemented implants showed high levels of zirconium in blood and serum, but not in cerebrospinal fluid. Aluminum did not appear high in the group of implants despite its presence in certain implant alloys.

The integrity of the blood-brain barrier, evaluated by the serum rates of S-100B, does not seem to be affected and without compromise in the implant group. Among those with cobalt or high cerebrospinal liquid zirconium, the serum S-100B rates were lower than those of the paired witnesses.

The results indicate that the metallic particles released from joint implants can accumulate in the central nervous system, in particular those containing cobal-chrome-molybdenum.

The results suggest that exposure to metals related to arthroplasty is not limited to local tissues but extends systematically and can involve the brain. Although the dysfunction of the blood-brain barrier is not obvious, the presence of these metals in the cerebrospinal fluid raises questions about long-term neurological security.

Additional research is necessary to determine whether the exhibitions observed can contribute to cognitive changes or to neurodegenerative diseases, in particular in those with components containing cobalt or unexplained neurological symptoms after arthroplasty. As a pilot study with exploratory objectives, no causal link can be established from this data.

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