Prosthetic hip-associated cobalt toxicity: a systematic review of case series and case reports

Abstract

Prosthetic hip-associated cobalt toxicity (PHACT) is caused by elevated blood cobalt concentrations after hip arthroplasty. The aim of this study is to determine which symptoms are reported most frequently and in what type of bearing. We also try to determine the blood level of cobalt concentrations associated with toxicological symptoms. A systematic review was conducted on the 10th of July according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A methodological quality assessment (risk of bias (RoB)) was performed. Primary outcomes were the reported symptoms of cobalt toxicity and the level of cobalt concentrations in blood. These levels were associated with toxicological symptoms. A total of 7645 references were found of which 67 relevant reports describing 79 patients. The two most used bearings in which PHACT was described were metal-on-metal (MoM) bearings (38 cases) and revised (fractured) ceramic-on-ceramic (CoC) bearings where the former ceramic head was replaced by a metal head (32 cases). Of all reported symptoms, most were seen in the neurological system, of which 24% were in the sensory system and 19.3% were in central/peripheral system, followed by the cardiovascular (22.1%) system. The mean cobalt concentration for MoM-bearings was 123.7 ± 96.8 ppb and 1078.2 ± 1267.5 ppb for the revised fractured CoC-bearings. We recommend not to use a metal-based articulation in the revision of a fractured CoC bearing and suggest close follow-up with yearly blood cobalt concentration controls in patients with a MoM bearing or a revised fractured CoC bearing. Level of Evidence: Level V, systematic review

Assessing brain integrity in patients with long‐term and well‐functioning metal‐based hip implants

“…We believe that this nonlinear relationship arises, most likely, from the blood-brain barrier that regulates components into the brain. Similarly, it might be possible thatrisk of developing diseases appears at 100 μg/L, or more, as suggested in 12 and that cobalt concentrations slightly above the risk threshold could beordinary for implanted patients. Many studies have criticized the 7 μg/L cut-off due to the lack of standardization in assessment and the likely interference of patient-specific factors in systemic cobalt toxicity.…”

“…Second, the lack of statistically significant differences suggests that the measured levels of metal ions in patients may still fall within biologically acceptable ranges. Alternatively, it is possible that the blood‐brain barrier restricts the entry of these metal ions into the brain, or once inside the brain, they bind with other components, like albumin, to mitigate their toxicity, thus preserving the diamagnetic susceptibility of healthy myelin that counters the paramagnetic susceptibility from iron, cobalt, and chromium 12 . Across both implanted and control subjects, the deep brain structures were observed to have significantly greater susceptibility compared to their middle and cortical brain counterparts, suggesting that the increased susceptibility of the deep brain structures is due to normal brain physiology, rather than implant wear and corrosion.…”

“…Previous case series have describedneurological symptoms associated with excessively high levels of metal ions, such as cobalt, in the blood. Hearing loss, depression, short‐term memory deficit, cognitive impairment, and Parkinson's disease have all been reported with excessively high cobalt content in the blood, with at least partial resolution following revision sugery 4–12 . However, most studies are based on adverse reactions, or unsuccessful implants, which primarily investigatethe extreme release of metal ion concentrations to the bloodstream or metal hypersensitivity.…”

“…impairment, and Parkinson's disease have all been reported with excessively high cobalt content in the blood, with at least partial resolution following revision sugery. [4][5][6][7][8][9][10][11][12] However, most studies are based on adverse reactions, or unsuccessful implants, which primarily investigatethe extreme release of metal ion concentrations to the bloodstream or metal hypersensitivity. There has beenno study that hasconsidered the joint evaluation of both brain anatomy and physiology (brain integrity) in well-functioning devices versus population-based controls without joint replacement.…”

Health risk assessment and metal contamination in fish, water and soil sediments in the East Kolkata Wetlands, India, Ramsar site

“…In the present investigation, Nickel (Ni) was determined to be below 2 mg kg −1 in all the tissues, which is considered a concentration well within the safe level. Ni is essential for normal growth and reproduction in animals, including fish, and at the same time, it shows carcinogenic effects in higher consumption 71 . Generally, it presents in open aquatic systems through natural or human sources, which are circulated into the system by two processes, chemical and physical, using biological transport mechanisms of living organisms 72 .…”