Over 2,000 of the 3,500 people who had faulty DePuy Orthopaedics hip joints fitted in Ireland have so far been assessed and for the vast majority no further treatment will be required, the HSE has said.
An expert from Newcastle University in the UK has estimated that 1,400 Irish people will need the hip device replaced.
In August last year, DePuy Orthopaedics announced a worldwide recall of two hip replacement implants. The chrome and cobalt appliances were recalled because up to 13 per cent of those fitted with them needed to have them replaced within five years.
Some 3,500 people received the implants in Ireland in 16 public and 14 private hospitals.
Of those, 2,022 patients had attended for their initial recall appointment by mid-December, the HSE said. The remainder are expected to be seen by the end of January.
Those recalled have undergone a range of tests including X-rays and blood tests. The blood tests measure the level of cobalt and chromium in patients’ blood.
People are naturally exposed to the metals and a metal hip implant can also increase their levels in the bloodstream without any harm. But more elevated levels can be a precursor to an inflammatory response to the implant that could result in damage to the bone.
Some American experts have also highlighted the negative impact of increased levels of metal ions in the blood on other organs and have pointed to the well-known story of Erin Brokovich as an extreme example of side effects. Ms Brokovich fought for the residents of Hinkley California who experienced higher levels of cancer when their water supply was contaminated with very high levels of chromium.
In advice for surgeon’s reviewing hip replacements, DePuy has said those at highest risk of needing a replacement were women and people fitted with smaller sized implants. It has also said people with blood levels of chromium or cobalt of over 7 parts per billion should be retested in three months and should be considered for surgery.
Dr Thomas Joyce, reader in biotribology at the school of mechanical and systems engineering, Newcastle University, who spoke at a conference in Dublin at the weekend organised by legal firm Malcomson Law, said in studies he carried out with 500 patients, the DePuy joint had a failure rate of 50 per cent over six years.
He estimated that 1,400 of the 3,500 who received the hip implants would need surgery. The normal life of such an appliance was 10 to 20 years depending on the recipient. He said the “metallic wear debris” that comes off the joints caused tissue damage and could damage the bone.
“It can also travel round the body as well and we still don’t fully understand the long-term complications of that; the science is incomplete,” he said. He said there was a potential for neurological problems, but it was difficult to quantify and he had not recorded any evidence of such problems in his study. He also said the levels of chromium present in the Brokovich case were extremely high and not comparable.
A spokeswoman for the HSE said it was expected that for most patients involved, the recall would be precautionary, but they would continue to be monitored for at least five years.
A small number of hospitals had already scheduled some revision surgeries and some surgeries had already taken place, she said.
The hospitals will recoup the costs of the operations directly from DePuy.
DePuy said its top priority was patient safety. It said it would reimburse all reasonable medical costs associated with the recall process, and had set up a separate scheme for patients to apply for reimbursement of non-medical costs associated with the recall such as travel and time off work. Irish firm Thompson and Partners is to manage the scheme.
