Thousands of hip replacement patients may be at risk of metal poisoning due to hidden wear and tear of the implants used, campaigners have warned.

Issues stem from a type of 'flexible' prosthesis used in the UK between 2009 and 2017, particularly among younger patients who were thought to benefit the most. 

However, it was later discovered these implants, which had cobalt components, could degrade, leading to tiny fragments of metal leaking into the bloodstream.

Cobalt poisoning has been linked to memory loss, depression, vision and hearing problems and heart failure and nerve damage.

Although withdrawn from use it is believed around 5,000 patients may have had cobalt implants and patient groups are now urging the NHS to contact all those known to have had one, so they can be monitored. 

One woman has gone public sharing how a hip implant she received back in 2014 had a devastating impact on her. 

Former fitness instructor Tracey O'Neill had hoped the procedure would help her regain her mobility when she first went in for the op aged 46. 

Instead, she has suffered health issues for years that have left her feeling like she is 'trapped in a 90-year-old's body' and at one point left people doubting her sanity.

Mrs O'Neill, who had a second similar implant installed in her hip in 2015, first noticed general pain and swelling around the joint.

By 2019 she was suffering shortness of breath and fatigue as well as issues with her heart.

'I got to the point that I couldn't even, in a basic yoga class, I couldn't get down and up from the floor,' she told The Telegraph. 

'Sometimes I would be talking to people and I would just forget the next word. People would think that I had just lost my marbles.'

Despite Mrs O'Neill suffering these issues for years, and the NHS stopping the general use of these implants by 2017 after the risks became clear, it wasn't until 2020 until medics made the link between her symptoms and the artificial joint. 

Now 56, she has since undergone surgery to remove the first of the implants, replacing it with one made from an alternative material, and the second one is being monitored for signs of wear and tear. 

Mrs O'Neil claims no one from the NHS has taken responsibility for the lack of follow-up that to the cause of her symptoms being missed for so long and fears many other patients could be in a similar situation.

The cobalt-chrome implants were originally touted as innovative when they were first launched, having greater flexibility than the standard artificial joints and persevering more of a patient's original healthy tissue. 

However, it was later discovered that the wear and tear between the metal parts of the implant could cause tiny metal particles to leak into the blood stream.

These could then react with body's natural fluids to essentially create a chemical battery reaction, causing a host of potential health problems.

It is estimated that 100,000 patients have had cobalt implants globally.

Not all these implants are expected to fail but campaigners say any patient who has one should be monitored to ensure its ongoing integrity. 

Dennis Reed, director of Silver Voices which campaigns for the over-60s, called on the NHS and medical safety regulators to urgently track down those who may have received these implants. 

'All patients potentially affected should be contacted and their current health conditions assessed, with a hip replacement option if it proves necessary,' he said.   

While many surgeons have now moved away from using the implants, due to increased rates of failure and health issues, they are still technically available as an option not being banned. 

Other implants that use cobalt-chromium are also still in use, though these are paired with other materials that reduce the risk of the wear and tear seen in the older models. 

However, some surgeons have called for hip replacements to avoid using cobalt in any implant, due to fears of its toxicity.

Responding to calls for action the UK medical device regulator, the Medicines and Healthcare products Regulatory Agency, said they continue to monitor the safety of hip implants and seek expert advice on if action is necessary in reports of problems. 

An NHS England spokesperson added that the health service would support any action deemed appropriate by regulators. 

University Hospitals Coventry and Warwickshire NHS Trust, who carried out Mrs O'Neill's original operation, said they were sorry to hear of her difficulties. 

A spokesperson added there was no indication of issues with the implants back in 2014, and follow-ups were not mandatory for patients in Mrs O'Neill's circumstances.