Cobalt Poisoning Cases Identified With No Hip Pain Symptoms

Two separate medical cases, published in leading medical journals the same week, highlight mysterious symptoms that were eventually attributed to metal poisoning from a metal-on-metal (MoM) hip prosthesis.

A paper published February 8, in the British medical journal, The Lancet, described a German patient’s quest for an accurate diagnosis. His condition worsened over about three years. His heart was weakening and could not pump blood through his body. He was almost blind and had lost his hearing and was losing his vision. He had low thyroid hormones. What didn’t make sense to this doctor was the fact that the man’s arteries did not show any sign of coronary artery disease.

A hip implant at the center of a medical mystery? Go figure.

The article reports the ailing man ended up in the German clinic of a Dr. Juergen R. Schafer, of Phillips University, Marburg, who happened to be a fan of the television show “House,” about a cantankerous doctor with uncanny diagnostic powers. In one particular episode, Dr. Juergen remembered the diagnosis after similar symptoms presented – cobalt poisoning from an artificial hip. This particular man had a metal hip implanted in November 2010 just before his symptoms began.

Blood tests show his cobalt level was one-thousand times over the normal level. Apparently when the patient’s original ceramic hip was removed it broke and left pieces behind that ground into the new metal hip. After his metal hip was replaced, his heart function returned almost to normal. There was no fever but his eyesight and hearing were never restored to normal.

The article in The Lancet, “Cobalt intoxication diagnosed with the help of Dr. House,” was authored by Dr. Juergen, along with others and concludes “cobalt intoxication is an increasingly recognized and life-threatening problem.”

The other article appears in The New England Journal of Medicine (February 6) concerning a woman from Denver who had suddenly gained 10 pounds, felt ill and had fluid accumulating around her heart. Her heart was failing and she underwent a heart transplant in September 2011. Blood tests revealed cobalt levels 300 times normal and her cardiologist suspected the toxic metal was poisoning her organs. Her metal-on-metal hips were replaced, both of them, with a polyethylene liner which brought the cobalt levels down. Her energy increased.

Without any symptoms of a failing hip it’s difficult and unlikely that cobalt poisoning would be diagnosed, reports her transplant specialist at the University of Colorado.

Cobalt poisoning was first identified among beer drinkers in Quebec in the 1960s. The foam of their beverage had been stabilized with a substance that contained cobalt. The Lancet article also points to the exposure of steel workers to cobalt who developed cardiomyopathy.

It was thought that cobalt was stabilized when combined with chromium and molybdenum but when metal-on-metal parts grind or ceramic debris is left behind to corrode the metal, the stage is set for metal toxicity. Clearly there needs to be more interpretation of MoM poisoning in clinical practice.

DePuy, a unit of Johnson & Johnson, has offered $2.47 billion to thousands of hip implant victims who required early revision surgeries to remove the DePuy ASR metal-on-metal hip. The company promises to settle more cases as they come in. The article above raises the question of how many hip patients may have symptoms not attributed to their metal hips gone wrong and how many may never know why their health suddenly went downhill.