Toxic time bomb ticking in metal hips
By LAWRENCE MONEY
When floods inundated rural Charlton in 2011, Di Harvey was in the thick of the salvage operation. A lively ex-nurse, Harvey and husband Jim had moved to this north-west Victorian town from NSW six years earlier and opened an antique store in the town’s historic Rex Theatre, the only cinema between Mildura and Bendigo. The floods of 2011 washed out both the cinema and her shop but Harvey, in characteristic fashion, threw herself into the community effort to restore the town – then set about rebuilding her business, at age 60.
However, her work was hampered by unexpected health problems. For many years she had been troubled by nagging back pain which had been attributed to a “pinched nerve”. She had been prescribed the usual pain-killers and anti-inflammatories, but relief was temporary and eventually the pain became excruciating. By 2010 Harvey felt the need to seek help from an orthopaedic surgeon in Bendigo and his diagnosis left her stunned. Her back problem, he said, was transferred pain from her artificial right hip which had been installed in 2003 by a surgeon in country NSW.
“The Bendigo surgeon said the hip had failed and needed replacement,” she recalls. The prosthesis had been hailed as a breakthrough at the time – made of cobalt-chromium alloy, the BHR (Birmingham Hip Resurfacing) system was the latest in metal-on-metal (MOM) hip joints and the installation cost more than $25,000. “The NSW surgeon had described it as the Rolls-Royce of hips,” says Harvey. “It was expected to last 15 to 20 years.”
But, just seven years later, there was little choice – she needed what surgeons call “revision” – replacement of the prosthesis. After a year on the medical-insurance waiting list, during which incapacity forced her to sell her antiques business, Harvey had her BHR replaced with a ceramic blend – but the problems were only starting. Twelve months after the revision – which cost another $30,000 – she developed knee pain. The pain from the right hip had caused her to favour the left leg and now she needed, and duly received, a knee replacement.
However, the strange medical symptoms that followed were more sinister. “I developed a hacking cough,” Harvey says. “I got very sick, began vomiting bile every day. I had heart palpitations. I felt if I over-exerted myself I would drop dead.”
She began researching her baffling conditions and was alarmed to discover growing concern about suspected metal “leaching” with MOM hips. An article in the Medical Journal of Australia in June 2011 had declared an “emerging clinical problem”. A trio of Queensland medical specialists, Professor Xinzhan Mao, Dr Andrew Wong and Professor Ross Crawford, wrote that the cobalt and chromium in metal hips released “a variety of metal ions into local tissue and [into] the general circulation…”
The medical trio said increased cobalt levels had been reported to be associated with hand tremors, depression, vertigo, hearing loss and heart problems. In case studies of two patients with DePuy hips, their symptoms “were related to their elevated cobalt levels, resulting from cobalt leaching out of their hip prostheses. Both patients had MOM prostheses and [their] cobalt levels were reduced after removal of the MOM… We are concerned that cobalt toxicity may be under-recognised…”
Says Harvey, now 64: “I have got rid of my BHR hip, but I have been told that once the cobalt and chromium get into your body the damage has been done.”
Melbourne barrister Andrew Archer knew none of this when, at age 41, he had an MOM hip implanted in 2008. It was a Mitch Stryker THR resurfacing and, says Archer, was “nothing but pain from the word go”. He had four further operations in the next six years, he says, but there was little primary relief. “On a bad day, the pain was simply too much to bear,” he says.
“My wife said it was like living with a different person – and we’ve been together 20 years. From 2000 to 2005 I worked in a top-tier law firm at full pelt – almost four years without a decent holiday, which was my choice. With the hip, I was struggling to get through an average week and I started having uncharacteristic health problems. Severe chest pains, extreme fatigue, sensitivity to light and other bizarre and unexplained infirmities. There was a merry-go-round of medical appointments, with all their time and cost implications.”
In September, last year, Archer had the hip replaced with a ceramic model, but recovery has been long and arduous, including five trips to emergency departments by ambulance and re-admission to hospital in the first eight weeks. “The surgeon has been very good but, after my revision last year, when I kept going back to hospital for weeks on end, my six-year-old son kept asking: ‘Is Dad going to die?’. We have no family in Melbourne. The burden my wife has carried with three young children has been extraordinary.”
For another MOM hip recipient, Lianne Slinger, a fall at work in the early 1990s triggered a chain reaction which has left her, at age 51, stricken by a multitude of health problems. She is one of hundreds on a Facebook site called Total Hip Replacement News where many report and compare their symptoms. Slinger had a total hip replacement in 1999, using a Sulzer MOM prosthesis. “I’ve been so sick it’s not funny,” says Slinger. “Sensitivity to light, headaches, swollen legs, facial numbness, chronic vertigo. But until I started falling over two years ago doctors took no notice of my complaints. I did not know about the suspected leaching until July last year when I was tested for cobalt/chromium. It came back as high. I have lost two kilos this week because I can’t eat. I still have the implant. There’s what’s called ‘pseudo tumour’ in there now – I’m told that’s what you get when you have cobalt in your body.”
A fourth MOM hip recipient is Janis Boys who, like Di Harvey, was told her prosthesis was the “Rolls-Royce of hips”, but she says it caused her “nothing but pain for the next three years”. Boys was fitted with a DePuy ASR MOM hip and says the resultant pain “affected my whole life and my relationship with family and friends”. However, there is one major difference between Boys and the other three – the DePuy ASR (Articular Surface Replacement) hips are the subject of a current class action in the Australian Federal Court where Boys attended the first day five weeks ago. The case is expected to run for months, and may affect up to 5000 Australian recipients of DePuy ASR hips who are seeking many millions in compensation.
Maurice Blackburn, which is leading the class action, says that the DePuy ASR hip implants were installed in Australian patients from 2003 until December 2009, when manufacturer Johnson & Johnson withdrew the devices from sale in Australia. J&J issued a “safety alert” for DePuy patients in March 2010 and a “hazard alert” in August 2010. Maurice Blackburn says that any compensation won will benefit only recipients of DePuy hips.
Hip replacements are the most-common form of joint surgery in Australia after knees and, as the population ages, the number of procedures has been steadily increasing. In 2014 there were almost 42,000 hip replacements (up from 5828 procedures in 2000) or about 800 a week. Professor Richard de Steiger, orthopaedic surgeon based at Epworth Hospital, says total hip replacement has been described as “the world’s most successful [surgical] operation”. When such large numbers of devices are used, he says, there will always be a small number of failures. With MOM hips such as the Sulzer, with smaller-diameter “ball”, failure rates are no higher than with standard hip replacements.
Smith & Nephew is a large UK-based multi-national that produces the BHR MOM hips, the type fitted to Di Harvey in 2003. It was little comfort to her when S&N issued an “urgent field safety notice” two months ago, cautioning about the use of BHR for “certain population sub-groups”. Two of the “sub-groups” accounted for more than half the population – all females and men over 65 years of age.
S&N, which generated $4.6 billion in revenue last year, said it was updating its “instructions for use” after data indicated an “increased risk of adverse outcomes”.
Australian Orthopaedic Association president John Tuffley says he is unsure why S&N issued the notice because this problem “has been known and acted upon by surgeons for many years”. He said resurfacing declined in Australia from 8.8 per cent in 2005 of hip replacement to 1.3 per cent in 2013. “It is now confined to… larger males below 65 years of age with osteoarthritis”, says Tuffley.
S&N’s notice made no mention of the possible effects of metal leaching, nor did the company respond when asked directly about it by Fairfax Media. However, Australia’s Therapeutic Goods Administration (TGA), the national safety monitor for such devices, says there is “insufficient evidence at this time to demonstrate that MOM hip implants produce side-effects beyond those that might occur at the site of the implantation”. And the Australian Orthopaedic Association says many MOMs have performed well and “a blanket ban on them would prevent some good implants from being used”. Nevertheless, the TGA in July 2012 reclassified (with a three-year compliance deadline) all hip, knee and shoulder prostheses (metal or otherwise) from “medium risk” to “high risk”.
There is little doubt that – implants aside – high levels of chromium and cobalt in the body are deleterious. Professor de Steiger says high levels of cobalt can produce effects throughout the body “including the heart and nervous system”. According to the National Organisation for Rare Disorders, based in the US, excessive chromium in the human body can cause lung cancer and kidney disease. Excessive cobalt can lead to nausea, vomiting, nerve damage and respiratory disease.
In 2013 three South Australian ophthalmologists sounded a warning about eyesight “complications” from cobalt toxicity. Soo Ng, Andreas Ebneter and Jagjit Gilhotra said this was an emerging problem given the “increasing number of… metal-on-metal hip implants”. Writing in the Indian Journal of Ophthalmology, they said that, in patients with “toxic” cobalt levels, the optic nerve had been damaged.
The Queensland specialists – Mao, Wong and Crawford – said that, while there is a “long clinical history of good outcomes” with hip replacement in Australia, some MOM implants had not lived up to the promise of increased durability. And although Smith & Nephew told Fairfax Media that its BHR system was performing well, and that “patient safety is always S&N’s first priority”, the company’s 2013 annual report clearly concedes the possibility of its products causing harm: “Design and manufacturing defects with respect to products sold by [Smith & Nephew], or by companies it has acquired, could damage, or impair the repair of, body functions. The Group may become subject to liability, which could be substantial…” Neither Sulzer nor Stryker responded to queries from the Sunday Age.
For Di Harvey, Lianne Slinger, Andrew Archer and hundreds of other Australian recipients of non-DePuy MOM hip implants, the current class action offers no joy. Says Harvey, who is now suffering eyesight problems: “I think [the medical authorities] are hoping we will shut our mouths and go away.”
One glimmer of hope comes from Bill Madden, medical law specialist with Slater and Gordon (which is not involved in the DePuy case) who says a successful legal action on one product can often help others seeking redress over similar products of other brands. “It depends on the basis of the claim,” says Madden. “If the claim alleges that manufacturers should have known of a particular risk, yes. If there is some particular manufacturing defect unique to an individual manufacturer, then obviously not.”
YOUR NEW HIP
- Hip implants are designed to replace the “ball and socket” hip joints that have degenerated, or been damaged through injury, and become painful.
- Conventional hip replacement involves a metal “ball” fitted into a polyethylene “socket”. In metal-on-metal hips (MOM), both ball and socket are metal.
- There are two types of total hip replacement (THR).
- In a conventional THR, the metal ball (and its stem) replaces the top of the thigh bone.
- In THR resurfacing, the ball is part of a capping on top of the thigh bone.
- THR with a ball over 32mm is called a “large head” replacement.
- The friction and corrosion between the moving parts in a large-head MOM implant produces metal ions whose effects on the body have yet to be precisely determined.
- THRs are the most-common form of joint surgery after knees.
- An average of 807 hips a week were implanted in Australia in 2014.
- Numbers have increased each year – from 5828 in 2000 (first full year for stats) to 41,973 last year.
- To date, there have been 456,695 THRs installed since 1999. Large-head MOM hip implants are no longer used.
- Resurfacing has decreased markedly. Source: Australian Orthopaedic Association