While it may seem worrying when an automobile is recalled due to a manufacturing error or product failure, a product recall takes on a whole new dimension when it relates to a surgically implanted medical prosthesis. But this is what has recently happened with a large scale hip replacement recall due to the danger of cobalt and chromium poisoning in those affected.
The cause of the problem is a chrome cobalt metal-on-metal hip arthroplasty prosthesis where abrasion of the metal ball and cup components is causing high blood levels particularly of cobalt in those affected.
Cobalt-chromium metal-on-metal hip prostheses have been deployed with increasing frequency over the last decade - especially in relatively active younger patients.
In April 2010, the UK’s Medical Products and Healthcare Devices Regulatory Agency issued a medical device alert that recommended annual blood testing for cobalt toxicity of all those who have received metal-on-metal hip replacements for 5 years post-operatively.
Then in August 2010 DePuy Orthopedics, a division of Johnson & Johnson, recalled two of its metal-on-metal hip replacement systems - the ASR Hip Resurfacing System and the ASR XL Acetabular System - due to high failure rates. The recall was initiated after the U.S. Food & Drug Administration (FDA) received hundreds of complaints from angry hip implant patients whose DePuy implants had failed shortly after surgery or caused other health problems.
Estimates are that approximately one-third of all hip replacements may be at issue with 39,000 Americans affected. 12% of DePuy hip implant patients may need to undergo revision surgery within just five years which is an unacceptable percentage by any standards.
There have been several case reports published detailing a catalogue of symptoms following placement of the hip prostheses. In such cases upon surgical revision the femoral head of the implants has shown almost total deterioration within just a couple of years and the bone and surrounding tissues are reported to have been extensively contaminated with metal debris.
Tissue samples taken at the time of surgery have revealed metallosis indicated by the formation of giant cells and fibrosis. Serum and fluid samples have shown high levels of cobalt, chromium and molybdenum with the concentration of cobalt, in particular, being remarkably high - in some cases over 100 fold normal physiologic levels.
Surgical replacement of the troublesome prostheses has resulted in an improvement in some or all symptoms in many patients.
Lawsuits now allege that Johnson & Johnson had known about the high failure rates and metal toxicity issues long before initiating the recall and had failed to warn patients about the potential side-effects and likelihood of having to undergo further surgery.
In an unrelated case, another hip prosthesis - the Zimmer durom cup implant - has also recently been recalled in the US only because of problems with the coating on the cup causing a failure to integrate with the pelvic bone.
The word cobalt comes from the German kobold meaning 'goblin' because early attempts to smelt the ores to obtain copper and nickel were unsuccessful and many were poisoned by the toxic arsenic vapours given off in the process.
Cobalt is produced as a by-product of copper and nickel mining and the copper belt in the Congo is the biggest source. The pure metal is not found in nature, but cobalt compounds are relatively common. The various chemical processes used to process the ores from copper and nickel can also contaminate water supplies with arsenic compounds and cobalt too can also leach into the environment from the slag.
Cobalt metal is used in:
Corrosion and wear-resistant alloys used in applications such as turbine blades and drill bits
Dental and medical prostheses including hip and knee replacements
Rich blue colourings and pigments used to colour glasses and ceramics
Radioisotopes of cobalt are used in radiotherapy and various industrial applications including radiation sterilisation of medical supplies and waste and foodstuffs. The radioactive half-life of cobalt-60 is just over 5 years which means that the radioactive source has to be replaced fairly regularly. One of the worst radiation contamination incidents in history occurred in 1984 when a discarded radiotherapy unit containing cobalt-60 was mistakenly disassembled in a scrap yard in Mexico.
Lithium-cobalt and other batteries
Platinum jewellery and
The production of petroleum and tyres.
The naturally occurring mineral form of cobalt is incorporated into vitamin B12 or cobalamin, and is an essential trace element with deficiency causing anaemia. The human body also employs some cobalt-containing enzymes in extracting energy from proteins and fats.
Most diets provide adequate intakes of cobalt but increasing amounts in the soil have been shown to markedly improve the health of grazing animals.
Symptoms of cobalt toxicity
Up until recently cobalt toxicity was largely an industrial issue relating to workers habitually exposed to cobalt dust from drilling or polishing. Inhalation of cobalt dust is known to cause respiratory problems including coughing, wheezing, shortness of breath, asthma and pulmonary fibrosis.
Cobalt dust can also cause irritation of the eyes and prolonged contact with cobalt can cause sensitisation and is the second most common cause of contact dermatitis after nickel. Accidental ingestion can also cause abdominal pain and vomiting.
Cobalt has been confirmed to be a carcinogen in animal studies and is considered a possible carcinogen in humans. It is also known to be toxic to aquatic organisms and to bioaccumulate up the aquatic food chain.
Here are just some of the metal toxicity symptoms associated with cobalt poisoning:
Vertigo and problems with balance
Poor memory and cognitive function
Tinnitus and hearing problems including deafness
Visual impairments including blindness
Cardiomyopathy (where the heart becomes ineffective at pumping blood), thickening of the blood and heart failure. In 1966, cobalt added to Canadian beer to stabilise the foam caused widespread 'beer drinker's cardiomyopathy'.
Peripheral neuropathy with tremors and loss of coordination
Kidney failure and
Anxiety and irritability.
The affected patients should be vigilant for any of the above signs in addition to local signs and symptoms surrounding the hip replacement such as:
Persistent or worsening hip or groin pain
Severe inflammation and
Evidence of tissue necrosis or bone loss.
Final thoughts on metal prostheses
ALL toxic and heavy metals are very damaging to the body causing chronic mental, physical and emotional symptoms. Often their effects are insidious and subtle taking a long time to develop and proving very hard to reverse.
Indeed, I would define this as the very nature of chronicity.
Metals have no place in the body or in dentistry.
All metals deployed within the body such as staples, prostheses and dental work become electrically active and subject to corrosion when placed within the moisture of the internal environment. So it is best to avoid exposure to - and especially implanting - toxic metals wherever possible.
As someone who had a 38 cm (15") metal 'nail' inserted in her femur just under a year ago as a result of an accident and who is only now able to walk tentatively without a stick, I am currently debating whether the trauma of having surgery to remove the nail outweighs the possible adverse effects of future metal toxicity.
As I know from bitter personal experience of getting occupational mercury poisoning as a result of being a dentist, removing the metal ions once they have been allowed to become lodged in every cell and organelle of the body is extremely challenging.
In addition to their toxic and electrical effects, all metals within the body interfere with, and block, energy meridian flows and this effect can also be responsible for a wide range of diverse symptoms.
For more about the effects of toxic metals and a self-help programme of metals detoxification please refer to Chronic Fatigue, ME and Fibromyalgia: The Natural Recovery Plan.