These questions and answers are about the hazard alert and recall of zirconia femoral head hip prostheses.
Q: What types of hip are affected?
Hip prostheses are modular devices comprising several components, depending on the design. Only those hips with a Zirconia femoral component, manufactured by the St Gobain Céramiques Advancées Desmarques company in France since 1998, are affected. Whether or not the Zirconia component has been used depends on the implanting surgeon's judgement as to the clinical situation of each patient.
It is important to note that hip implants with femoral head components made from other materials such as alumina or steel are NOT affected. Zirconia femoral head prostheses manufactured by either Ceramtech or Morgan Matrock are NOT affected either.
Q: How many patients are affected in Australia?
The number of batches affected and therefore the number of actual femoral heads affected is uncertain at this stage.
So far, adverse event reports have been received on 5 batches of the product, although up to 9 batches may be implicated. Within these batches the failure rate has been as high as 8.8%.
It has been estimated that about 9000 Australian patients have been implanted with zirconia femoral heads prostheses since 1998.
Q: Which Australian sponsors hips are affected?
It is understood St Gobain Céramiques Advancées Desmarques manufactures zirconia femoral head components to approximately 80% of the world market supplied by some 39 different hip implant manufacturers. Of these only 6 sponsors supply in Australia:
- Biomet
- Depuy
- Smith and Nephew
- Taylor Bryant
- Stryker
- Zimmer
Q: What are the timeframes for the hip failures?
The current spontaneous disintegration of the zirconia femoral heads appears to be occurring between 13 and 27 months after implantation, but long term studies are not yet available. This is different to previous experience with this type of device where it is generally recognised that 1 in 10,000 units may fracture early on after implantation.
Q: For how long will the problem continue?
This is difficult to determine at this stage, as the root cause of the problem is yet to be determined. So far there has been adverse event reports associated with five batches manufactured in Jan and Feb 1998. These events are of failures occurring 13-27 months after implantation. Implants from these batches may continue to fail into the future.
Q: Are other types of orthopaedic prostheses affected?
In addition to the femoral head components, St Gobain Céramiques Advancées Desmarques manufactures ceramic components for knee, shoulder and wrist prostheses and the acetabular component of hip replacements. TGA is trying to determine whether these other products are subject to the same problem. To date, there have been no reports of adverse events associated with these other devices.
Q: Are patients being notified?
The TGA and the sponsors of affected hip implants in Australia have sent information to surgeons, hospitals and other health authorities. It is expected that surgeons will contact their patients about this problem.
Q: How long will my hip replacement last?
This is hard to make a definite statement on. The TGA in conjunction with regulatory authorities worldwide are trying to determine the extent of the problem. If you have received an implant from a batch which was not affected there is no reason not to expect that the implant will work well for between 10-20 years. The latest figures from investigations are that up to 8.8% of hips in the affected batches have spontaneously disintegrated between 13 and 27 months after implantation. However, longer-term studies are not yet available and it is possible that affected hips may fail after much longer implantation times.
Q: How many hips are affected?
It is not known if all St Gobain Céramiques Advancées Desmarques zirconia femoral head batches will be affected, but a full analysis is being undertaken to determine the extent of the problem. If all St Gobain Céramiques Advancées Desmarquest zirconia femoral batches are affected by the problem, approximately 200,000 hips will be affected worldwide and approximately 9000 hips in Australia.
Q: How do I find out what sort of hip I have?
You should contact your surgeon who implanted the device, or the hospital where you had the hip implant operation. They should be able to check your medical records and advise.
Q: How do I find out if my hip is affected (are there any tests)?
At this point there are no tests that will be able to detect whether the zirconia head is likely to fail in the future. The disintegration is reported to be spontaneous.
Q: How will I know if something has gone wrong with my hip? What should I do then?
If you experience any of the following:
- A sudden inability to walk; and/or
- A sudden pain in your hip; and/or
- A sudden 'jolt' in your hip that has been operated on,
Seek urgent medical attention by:
- Contacting your specialist orthopaedic surgeon; or
- Contacting your general practitioner; or
- Contacting the nearest emergency department
Q: What are the potential clinical outcomes should my hip fail?
The problem is not life threatening, but you will need to have the hip replaced. This is major surgery, and your surgeon will be able to advise on your particular circumstances.
Q: Is it necessary to have my hip implant replaced?
Expert opinion does not recommend preventative replacement of any of these implants at this stage. Replacement should only be considered if the femoral head has failed or if the implant requires revision for other reasons.
Q: Where do I go for further information?
In the first instance, you should contact your orthopaedic surgeon for further advice on your particular situation. The hospital where you had your hip implanted and the manufacturer of the hip that you received should also be able to provide some additional information. The TGA website contains further information on this issue and will be updated as further information comes to hand.
Q: What do I have to do now?
Contact the surgeon who put in your hip prosthesis for further advice. You should ask for details of the type of implant (name, model, serial number if possible) - this should be available from your medical records at the hospital where the implant was performed.
Carry with you the phone number and contact details of the surgeon and implanting hospital in case your hip fails.
If you have already sought advice from your surgeon and have taken these preliminary steps, there is nothing further to do. You should carry on with normal activities as advised by your doctor.
Q: Should I postpone my surgery?
There are a number of alternative replacement joints available. The type of joint best suited to your needs (age, weight, level of activity and so on) will be discussed with you by your surgeon.
Sometimes your surgeon may wish to postpone surgery until the right component is available. You should consult with your orthopedic surgeon about the options available.
Q: What are the alternatives to Zirconia femoral heads?
Femoral heads are also made from steel and alumina (another type of ceramic). While St Gobain Céramiques Advancées Desmarques manufacture approximately 80% of all zirconia femoral heads, two other manufactures also make zirconia femoral head components. Products from these manufacturers are NOT affected by this recall action.
There is clinical evidence to suggest that zirconia femoral heads have improved wear properties compared to steel or alumina, and many surgeons use them in younger patients.