Fatal Cobalt Toxicity after a Non-Metal-on-Metal Total Hip Arthroplasty

Abstract

This case illustrates the potential for systemic cobalt toxicity in non-metal-on-metal bearings and its potentially devastating consequences. We present a 71-year-old male with grinding sensations in his right hip following ceramic-on-ceramic total hip arthroplasty (THA). After diagnosing a fractured ceramic liner, the hip prosthesis was revised into a metal-on-polyethylene bearing. At one year postoperatively, X-rays and MARS-MRI showed a fixed reversed hybrid THA, with periarticular densities, flattening of the femoral head component, and a pattern of periarticular metal wear debris and pseudotumor formation. Before revision could take place, the patient was admitted with the clinical picture of systemic cobalt toxicity, supported by excessively high serum cobalt and chromium levels, and ultimately died. At autopsy dilated cardiomyopathy as cause of death was hypothesized. A third body wear reaction between ceramic remnants and the metal femoral head very likely led to excessive metal wear, which contributed systemic cobalt toxicity leading to neurotoxicity and heart failure. This case emphasizes that fractured ceramic-on-ceramic bearings should be revised to ceramic-on-ceramic or ceramic-on-polyethylene bearings, but not to metal-on-polyethylene bearings. We aim to increase awareness among orthopedic surgeons for clinical clues for systemic cobalt intoxication, even when there is no metal-on-metal bearing surface.

Analysis of Cellular Activity and Induction of Inflammation in Response to Short-Term Exposure to Cobalt and Chromium Ions in Mature Human Osteoblasts

“…Serum cobalt concentrations of 2–7 µg/L (0.002–0.007 ppm) or 10 µg/L (0.010 ppm) were stated respectively in a European multidisciplinary consensus statement [11] or by the Mayo Clinic [12] as indicative of metallic wear and implant loosening. The systemic concentrations reported in patients with acute cobalt poisoning after excessive wear particle release with fatal or near fatal outcomes were approximately a hundred times higher (serum levels of around 0.40–0.64 ppm cobalt and 0.05–0.08 ppm chromium) than the suggested threshold, with even higher values excreted in urine [13,14,15,16,17]. While cobalt concentrations are higher than chromium concentrations in serum this is reversed in the periprosthetic tissue, partially due to the above mentioned reasons.…”

Cobalt-related cardiomyopathy: A real concern! A review of published evidence

“…Thirteen cases were included in the probable group [11][12][13][14][16][17][18][19][20][21][22][23] based on the presence of either cardiac histopathology or Co systemic toxicity features and evidence of pre-existing risk factors for CMP (Table 4). Mean blood Co level was 425 mg/L with a range of 112-1556 mg/L.…”

Cobalt cardiomyopathy in hip arthroplasty

“…Thirteen cases were included in the probable group [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23] based on the presence of either cardiac histopathology or cobalt systemic toxicity features and evidence of pre-existing risk factors for CMP (Table 3). Mean blood cobalt level was 425 ppb (range 112-1556).…”