How do metal ion levels change over time in hip resurfacing patients? A cohort study

Psychiatric Disorders and Genotoxicity Following Primary Metal on Polyethylene Total Hip Arthroplasty and Their Correlation to Cobalt/Chromium Levels

Introduction

Hip arthroplasty (HA) using implantable metal components is among the commonest orthopedic interventions. However, it can be followed by several complications following corrosion and the release of metal ions. Several studies proved that damaged genomic DNA may contribute to the pathophysiology of mental disorders.

Aim

The current work aims to evaluate the psychiatric disorders in metal on polyethylene hip arthroplasty (MOP-HA) patients and its correlation to cobalt/chromium (Co/Cr) levels and genotoxicity.

Methods

The work was a longitudinal follow-up study including 34 adults with unilateral primary MOP-HA meeting the inclusion and exclusion criteria. Preoperatively, 6, 12-months-postoperatively, patients were examined for cognitive impairment using mini-mental-state-examination (MMSE), depression using major-depressive-inventory (MDI), and blood samples were collected for estimation of Co/Cr, detection of genotoxicity by single-cell-gel-electrophoresis (comet assay) and serum 8-hydroxy-2'-deoxyguanosine (8-OHdG).

Results

Cognitive impairment was reported in 18.5% and 14.8% at 6-months, and 12-months postoperative, respectively. Depressive disorder was recorded in 22.2% at 6-months and 14.8% at 12-months postoperative. The marginal homogeneity tests proved a non-significant difference. There was a non-significant difference in preoperative, 6-months, 12-months postoperative MMSE, and MDI scores. There were significantly increased Co/Cr levels at 6-months postoperative. The levels decreased at 12-months postoperative, however, still significantly higher than preoperative values. There was a significant increase in serum 8-OHdG and the levels were positively correlated to cobalt levels at both 6 and 12-months-postoperative. There was a non-significant difference among preoperative, 6-months, and 12-months postoperative comet assay measurements.

Conclusion

From previous findings, we can conclude that will-functioning MOP hip arthroplasty can induce increased ion levels and positively correlated increase in biochemical markers of genotoxicity (8-OHdG).

Self-reported systemic complaints in patients with metal-on-metal hip arthroplasty

Introduction

An increase in blood serum metal ion levels is seen after implantation of all metal-on-metal (MoM) hip prosthesis. Systemic complaints contributed to raised cobalt ion concentrations in patients with MoM arthroplasty may lead to a variety of symptoms. The aim of this study is to investigate self-reported systemic complaints in association with cobalt ion concentrations in patients with any type of MoM hip prosthesis.

Methods

A cohort study was conducted. Patients with both unilateral and bilateral, resurfacing and large head metal on metal total hip arthroplasties (LHMoM THA) were included. Cobalt ion concentrations were measured by inductively coupled plasma mass spectrometry. Based on the known cobalt toxicity symptoms of case-reports and toxicology reports a new non-validated questionnaire was developed. Analysis was performed on two groups; a low cobalt ion concentration group and a high cobalt ion concentration group.

Results

A total of 62 patients were included with a mean age at surgery of 60.8 ± 9.3 years and a mean follow up of 6.3 ± 1.4 years. Mean cobalt ion concentrations were 104 ± 141 nmol/L (9-833). Based on the different thresholds (120-170 or 220 nmol/L) the low cobalt ion concentration group consisted of 44 (71%), 51 (82%) or 55 (89%) subjects respectively. In the 120 nmol/L and 170 nmol/L thresholds a significant difference in age was found. The composite score for OVS increased from 54% to 57%-68% with rising threshold value, a hint at the correlation between ion concentration and symptom prevalence.

Discussion

Ocular-vestibular symptoms were more common in high cobalt ion concentration groups for the three threshold levels tested and with increasing prevalence for higher threshold values. With regards to proactively inquired, self-reported symptoms the threshold where effects may be present could be lower than values currently applied in clinical follow-up.

Chromium and Nickel Concentrations in Subjects with a Stainless Steel Metal-on-Metal Cervical Disc Arthroplasty: Results from a Prospective Longitudinal Study with 7 Years Follow-Up

Background

Cervical disc arthroplasty (CDA) has emerged as an alternative to anterior cervical discectomy and fusion for degenerative cervical disc disease. The artificial discs provide intervertebral motion using multicomponent articulation and thus tend to generate particulate debris and soluble metal ions. Limited information is available on the long-term metal concentrations and associated systemic adverse events observed in metal-on-metal CDA. Serum chromium (Cr) and nickel (Ni) concentrations were assessed in patients implanted with ball-in-trough stainless steel-based cervical disc through 7 years.

Methods

A prospective, nonrandomized longitudinal study was conducted that included 25 patients following rigorous exclusion criteria that included no previous permanent metal implants and no professional exposure to metal particles. Blood serum Cr and Ni concentrations were assayed preoperatively and at 3, 6, 12, 24, 36, 60, and 84 months postoperatively using high-resolution inductively coupled plasma-mass spectrometry. Longitudinal statistical comparisons were made using the Friedman test with statistical significance at P < .05.

Results

Median serum concentrations determined preoperatively and at 3, 6, 12, 24, 36, 60, and 84 months postoperatively were 0.074, 0.106, 0.132, 0.170, 0.172, 0.274, 0.192, and 0.203 ng/mL for Cr and 0.085, 0.178, 0.222, 0.175, 0.205, 0.284, 0.181, and 0.194 ng/mL for Ni. The serum Cr concentrations were statistically higher for all postoperative time periods compared to preoperative concentration (Friedman P <.01), whereas serum Ni concentration was statistically higher at the 84-month postoperative time period than the preoperative concentration (Friedman P <.01) and then the concentration at 3, 12, 24, and 60 months postoperatively (Friedman P < .03).

Conclusions

The Cr concentrations detected at all postoperative times were statistically higher than preoperative concentrations, whereas Ni concentration was statistically higher than the preoperative concentration only at 84 months.

Potential presence of metals in patients treated with metal-metal coupling prostheses for hip arthroplasty at 7 and 10 years of follow-up

BACKGROUND

Beginning in 2008, metal-on-metal prostheses have been in the spotlight owing to much higher revision rates than expected. Adverse local tissue reactions have been well described in the literature as potential complications.

METHODS

Between 2012 and 2013, 13 patients with metal-on-metal total hip replacements were evaluated clinically and radiologically and with laboratory samples. The same tests were repeated between 2015 and 2016 on eight patients to assess any changes. In the laboratory assessment, we searched for chromium, cobalt, molybdenum, and nickel in blood and urine samples over 24 h.

RESULTS

Clinical assessment has shown good score in all patients except one. On a second examination, between 2015 and 2016, all patients obtained results similar to those obtained in the first assessment, except a patient, who reported a recent fall. In the radiological assessment between 2012 and 2013, results were optimal, apart from a case of aseptic mobilization. The patients reassessed 3 years after the first examination showed radiological results similar to those previously obtained, apart from a patient, who showed signals of mobilization. Metal levels found in their blood decreased in most cases after 3 years. Urine levels of nickel increased in five subjects, and chromium levels increased in four, but levels of cobalt and molybdenum decreased in four patients.

CONCLUSION

It could be hypothesized that the decreasing trend of metal ion levels is associated with a stable wear status. On the contrary, a progressive increase in metal ion levels must be considered as early proof of implant loosening.

Biological effects of metal degradation in hip arthroplasties

Metals and metal alloys are the most used materials in orthopedic implants. The focus is on total hip arthroplasty (THA) that, though well tolerated, may be associated with local and remote adverse effects in the medium-long term. This review aims to summarize data on the biological consequences of the metal implant degradation that have been attributed predominantly to metal-on-metal (MoM) THA. Local responses to metals consist of a broad clinical spectrum ranging from small asymptomatic tissue lesions to severe destruction of bone and soft tissues, which are designated as metallosis, adverse reactions to metal debris (ARMD), aseptic lymphocytic vasculitis associated lesion (ALVAL), and pseudotumors. In addition, the dissemination of metal particles and ions throughout the body has been associated with systemic adverse effects, including organ toxicity, cancerogenesis, teratogenicity, and immunotoxicity. As proved by the multitude of studies in this field, metal degradation may increase safety issues associated with THA, especially with MoM hip systems. Data collection regarding local, systemic and long-term effects plays an essential role to better define any safety risks and to generate scientifically based recommendations.

Relationship between Pelvic Incidence Angle and Blood Concentration of Chromium and Cobalt Ions after Metal-on-Metal Hip Replacement: A Brief Report

BACKGROUND AND AIMS

The wear of metal-on-metal hip implants may increase chromium or cobalt ion blood level. This phenomenon may depend among other things on the particularity of spinopelvic anatomy. The effect of pelvic incidence angle on the wear of metal-on-metal hip implants is not known. The objective of the study was to investigate whether such effect does exist.

MATERIAL AND METHODS

The pelvic incidence and inclination of acetabular component angles of 89 patients after unilateral metal-on-metal hip replacement were compared with blood level of chromium and cobalt ions using Pearson correlation coefficient.

RESULTS

No significant correlations between pelvic incidence angle and the metal ion blood levels were observed. The correlation coefficients varied from -0.02 to 0.2 and all p values were >0.05.

CONCLUSION

No evidence was found on the effect of pelvic incidence angle on metal wear after metal-on-metal hip replacement when measured by the blood levels of chromium and cobalt ions. It is reasonable to assume that other factors than pelvic tilt may affect the rate of implant wear.

Trace metal determination as it relates to metallosis of orthopaedic implants: Evolution and current status

In utilising metal surfaces that are in constant contact with each other, metal-on-metal (MoM) surgical implants present a unique challenge, in the sense that their necessity is accompanied by the potential risk of wear particle generation, metal ion release and subsequent patient toxicity. This is especially true of orthopaedic devices that are faulty and subject to failure, where the metal surfaces undergo atypical degradation and release even more unwanted byproducts, as was highlighted by the recent recall of orthopaedic surgical implants. The aim of this review is to examine the area of metallosis arising from the wear of MoM articulations in orthopaedic devices, including how the surgical procedures and detection methods have advanced to meet growing performance and analytical needs, respectively.