Is end-organ surveillance necessary in patients with well-functioning metal-on-metal hip resurfacings?

Abstract

Aims Cardiac magnetic resonance (CMR) was used to assess whether cardiac function or tissue composition was affected in patients with well-functioning metal-on-metal hip resurfacing arthroplasties (MoMHRA) when compared with a group of controls, and to assess if metal ion levels correlated with any of the functional or structural parameters studied. Patients and Methods In all, 30 participants with no significant cardiac history were enrolled: 20 patients with well-functioning MoMHRA at mean follow-up of 8.3 years post-procedure (ten unilateral, ten bilateral; 17 men, three women) and a case-matched control group of ten non-MoM total hip arthroplasty patients (six men, four women). The mean age of the whole cohort (study group and controls) at the time of surgery was 50.6 years (41.0 to 64.0). Serum levels of cobalt and chromium were measured, and all patients underwent CMR imaging, including cine, T2* measurements, T1 and T2 mapping, late gadolinium enhancement, and strain measurements. Results None of the MoMHRA patients showed clinically significant cardiac functional abnormality. The MoMHRA patients had larger indexed right and left end diastolic volumes (left ventricular (LV): 74 ml/m2 vs 67 ml/m2, p = 0.045; right ventricular: 80 ml/m2 vs 71 ml/m2, p = 0.02). There was a small decrease in T2 time in the MoMHRA patients (median 49 ms vs 54 ms; p = 0.0003). Higher metal ion levels were associated with larger LV volumes and with shorter T2 time. Conclusion Although cardiac function is not clinically adversely affected in patients with well-functioning MoMHRA, modern imaging is able to demonstrate subtle changes in structure and function of the heart. As these changes correlate with systemic ion measurements, they may be consequences of wear debris deposition. Longer, longitudinal studies are necessary to determine whether cardiac function will become affected. Cite this article: Bone Joint J 2019;101-B:540–546.

Cobalt-induced cardiomyopathy – do circulating cobalt levels matter?

“…A small increase in heart complications in metal bearing surfaces compared to non-metal surfaces was identified after controlling for confounding factors and this was most pronounced in MoM versus CoC in patients over 75 years of age. 68 These studies represent a range of different experimental designs including cross-sectional observational studies 65 , 66 and population-based cohort studies, 67 , 68 and they find broadly similar results.…”

“…This suggests that adverse cardiac processes may be at work in asymptomatic MoM patients, even when they have normal or minimally elevated blood cobalt levels. 66 Population-wide studies have demonstrated cardiac complications in MoM patients without studying individual blood cobalt levels. A retrospective cohort study of the Australian Government Department of Veterans’ Affairs demonstrated that men with an ASR XL THA had a statistically significant higher rate of hospitalization for heart failure than men with a MoP THA.…”

Systemic toxicity of metal ions release from specific types of implanted medical devices: Systemic review of clinical studies

“…Berber et al [53] evaluated 90 patients with either ceramic on ceramic, MoM hips with low ion levels, and MoM hips with high ion levels (>7 µg L -1 ). In this study, there was no difference in cardiac MRI results.…”