17 August 2001
The Ministry of Health is working with suppliers and clinicians to identify New Zealand patients who may have received a
brand of hip joint replacement which is currently the subject of a recall.
The zirconia ceramic femoral head prostheses, manufactured by Saint-Gobian Ceramiques Avancees Desmarguest in France is
being recalled following reports of failure. The reports from France and the USA show that a small number of products
manufactured since 1998 had an increased failure rate and disintegrated 13 ?27 months' after implantation.
The French company is the major manufacturer of Zirconia implants in the world.
Ministry of Health senior medical advisor Dr Stewart Jessamine said that zirconia hip femoral head prostheses have been
used in New Zealand for a number of years, and the Ministry has not had any reports of this problem or other device
failure relating to this product in either Australia or New Zealand.
He said companies distributing the zirconia ceramic femoral heads in New Zealand have this week recalled all unused
product and surgeons have not implanted them since notification late yesterday.
Approximately 5000 hip implant operations are performed in New Zealand each year.
"Of these approximately 300 patients per year receive the zirconia ceramic implant. This means that since 1998
approximately 1000 zirconia ceramic femoral heads have been implanted in New Zealand patients.
Dr Jessamine said patients who have had a zirconia ceramic femoral implant and experience a sudden development of a
"grating sensation" in the hip, which may be audible, should see a GP and seek referral to an orthopaedic specialist. If
patients are unsure whether they have this implant, they should contact the hospital or surgeon where the surgery was
performed.
Zirconia Femoral Heads Used in Hip Prostheses:
Hazard Alert and Recall
Questions and Answers:
Q: What types of hip are affected?
The device recall notice affects only hip implants containing a zirconia femoral component manufactured by the St Gobain
Céramiques Advancées Desmarques company in France since 1998. It is important to note that hip implants with femoral
head components made from other materials such as alumina ceramic or steel are NOT affected.
The Ministry of Health decided to recall hip implants containing zirconia components after it was notified of an
increased rate of failure of the implants in 5 batches of the product manufactured since 1998. It is thought that a
change to the manufacturing process of the St Gobain zirconia implants that occurred in 1998 may be implicated in the
failure of the device and all hip implants manufactured since then should be considered to be suspect.
Hip prostheses are modular devices made up of several components, depending on the design. Whether or not a zirconia
component has been used in a particular implant depends on the implanting surgeon's judgement as to the clinical
situation of each patient. Under normal circumstances the rate of failure of hip implants is 1-in-10,000 units. The
failure rate for some of the affected zirconia containing femoral head implants is approximately 6%.
Q: How many patients are affected in New Zealand?
It has been estimated that about 1000 New Zealand patients have been implanted with zirconia femoral heads prostheses
since 1998. So far, no adverse event reports have been received by the Ministry of Health on the use of Zirconia ceramic
femoral head hip implants in New Zealand.
Q: Which New Zealand companies are distributing these affected hip implants?
There are four companies supplying the New Zealand market with St Gobain Céramiques Advancées Desmarques zirconia
femoral head components. Approximately 80% of the world market for zirconia femoral head prostheses is supplied by St
Gobain Ceramiques.
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. The Ministry is unable to determine if the failure rate for the affected devices will increase with
prolonged use as long term studies are not yet available.
Q: Who has been notified?
The distributors of hip implants containing Saint Gobain zirconia femoral head components in New Zealand have sent
information about the rate of failure of the device to the surgeons and the hospitals that have used this implant. All
unused implants have been withdrawn from supply. The Ministry is exploring the possibility of contacting patients who
have received a suspect Saint Gobain zirconia femoral head implant.
Q: How long will my hip replacement last?
It is not possible to make a definitive statement about each individual hip implant. The Ministry of Health in
conjunction with regulatory authorities worldwide is trying to determine the extent of the problem. If you have received
an implant from a batch which was not affected the implant should work for between 10-20 years.
Q: How many hips are affected?
If all St Gobain Céramiques Advancées Desmarquest zirconia femoral batches manufactured since 1998 are affected by the
problem, approximately 200,000 hips will be affected worldwide and approximately 1000 hips in New Zealand.
Q: How do I find out what sort of hip I have?
If you have had an implant since the beginning of 1998 you could contact the 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: Are there any tests that will tell me if my hip is affected.
Currently there are no tests that will be able to detect whether the zirconia head is likely to fail in the future.
Q: How will I know if something has gone wrong with my hip? What should I do then?
If you experience a sudden development of a "grating sensation", which may be audible, you should seek orthopaedic
advice.
Q: What are the potential clinical outcomes should my hip fail?
While failure of the device is not life threatening, you will need to have further surgery to replace the failed
implant.
Q: What are the alternatives to Zirconia femoral heads? There are other types of femoral heads made from steel and
alumina (another type of ceramic).