Medical Devices Safety Update, Volume 2, Number 6, November 2014

3 November 2014

Medical Devices Safety Update is the medical device safety bulletin of the Therapeutic Goods Administration (TGA)

Urogynaecological surgical mesh implants review

A TGA review into urogynaecological surgical mesh implants has highlighted the importance of appropriate patient selection, surgeon experience and the need for fully informed patient consent.

Urogynaecological meshes are used to provide additional support when repairing weakened or damaged tissue in urogynaecological procedures, including repair of pelvic organ prolapse and stress urinary incontinence.

The TGA has been monitoring these implants since 2008. In 2013, the TGA began an extensive review of urogynaecological meshes as a class of products. The Urogynaecological Devices Working Group was established to provide expert advice on the available clinical evidence associated with the implants, as well as the information supplied with these devices.

The results of the review were published on 20 August 2014. The review found there was an absence of evidence to support the overall effectiveness of urogynaecological surgical meshes as a class of product. However, it found that the use of these devices was adequately supported by the evidence in the surgical treatment of urinary incontinence and repair of abdominal pelvic organ prolapse. Due to the poor quality of the studies undertaken, the evidence to support use for transvaginal pelvic organ prolapse repair, particularly, posterior repair, is not well established. Subsequently, the TGA began reassessing the clinical evidence for each individual implant. This individual assessment is ongoing and, where individual meshes are found not to meet the required evidence standards, regulatory action - such as requirements to update the Instructions for Use, cancellation or suspension of particular mesh implants from the Australian Register of Therapeutic Goods (ARTG) - will be undertaken. Some urogynaecological meshes have already been cancelled from the ARTG, with notices published on the TGA website.

During the review, the TGA consulted with Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) and the Urogynaecological Society of Australia. More information for surgeons is available on the RANZCOG website, including discussion of issues such as informed patient consent, surgical training, monitoring of implants and patient selection.

If a patient with a urogynaecological mesh experiences any symptoms, including pain, or if they have any concerns about their device, they should be advised to contact their surgeon.

Latest National Joint Replacement Registry data offers insight into orthopaedic implants

The Australian Orthopaedic Association National Joint Replacement Registry annual reports offer insight into the performance of orthopaedic implants being used in this country.

Erratum: This article incorrectly reported that 18 implant combinations with higher-than-expected revision rates were newly identified in the annual reports. The number was in fact 19.

All figures relating to this number have been updated in the text below. Changes have been denoted by strikethrough text.

Eighteen Nineteen implants with higher-than-expected revision rates were newly identified in the 2014 annual reports of the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), which were published on 1 October.

The AOANJRR annual reports contain information about orthopaedic implants that are having higher-than-expected rates of revision.

The main AOANJRR report is based on an analysis of about 891,000 primary and revision hip and knee replacement procedures, with a procedure date up to and including 31 December 2013. Several thousand implant combinations are tracked.

A supplementary report covers a total of 22,544 shoulder implant procedures.

The reports compare the performance of individual implants with all implants of that type and identifies those that do not appear to be performing as well as the others, using the revision rate as a measure.

Joint replacement surgery is considered to be one of the most effective forms of surgical intervention and the overall revision rates are generally low, even for many of the implants for which the revision rate is considered to be higher-than-expected.

Regulatory intervention

In reviewing whether the implants identified in the reports require regulatory intervention, the TGA will seek advice from the Orthopaedic Subcommittee (OSC) of the Advisory Committee on the Safety of Medical Devices.

The OSC advises the TGA whether the reported revision are of significant clinical concern.

Based on this advice and other information, including that provided by the relevant sponsor, the TGA will then take regulatory action if required.

When regulatory intervention is necessary it is reported to all surgeons who have used the implants through a hazard alert and details of the action/intervention are published on the TGA website.

The TGA has contacted the sponsors of 14 15 of the newly identified implants (12 13 hip/knee and two shoulder) requesting responses to the AOANJRR data.

The remaining four implants that were newly identified in 2014 are no longer used.

Elevated revision rates

Higher rates of revision are of concern because, as with any major surgery, orthopaedic surgery is associated with significant health risks. However, there are many reasons why a particular implant may be having a higher-than-expected rate of revision (including patient-related factors such as age and level of activity) and an elevated revision rate does not necessarily mean that the TGA needs to take regulatory action.

The AOANJRR annual report lists a total of 48 49 hip and knee implants (both newly identified in this report and identified in previous annual reports) that had higher-than-anticipated revision rates and were still being used during the reporting period. The TGA may choose to continue monitoring implants and not take regulatory action, even though the revision rate is higher-than-anticipated, for a variety of reasons including:

  • the implant had been used in a select patient population that is at a higher risk of revision
  • use of the implant offers unique benefits that compensate for the higher risk of revision
  • the implant is very new to the market, has been used in low numbers and other the information indicates that the revision rate will decrease rapidly.

Apart from the 12 13 newly identified hip/knee implants discussed above that are still being assessed, the implants with higher-than-anticipated revision rates fall into two other categories:

  • identified before 2014 and still being used
  • identified and no longer used.

Identified before 2014 and still in use

The AOANJRR 2014 annual report lists 36 hip/knee implants that were identified in earlier reports as having higher-than-expected revision rates and which are still being used.

One of these is included because it had been in use until February 2014, but has been cancelled from the Australian Register of Therapeutic Goods.

The TGA is currently investigating four others and monitoring the remaining 31 implants following earlier reviews. Some of the reasons why TGA might decide to continue monitoring, rather than take regulatory action, are listed above.

Identified and no longer used

There are 69 hip/knee implants that have been identified with higher-than-expected revision rates, but are no longer used.

In 45 of these cases the implants were identified after they had already been withdrawn from the market.

The remaining 24 implants were withdrawn after reviews by the TGA and regulatory intervention, following the process described above.

Best practice model

All implants have a limited life in the human body and may need to be revised at some point in time. However, it is important to ensure that implants do not require replacement too often or too soon after implantation.

The TGA works closely with the AOANJRR and where it is confirmed that the implant is the primary cause of early revisions, the TGA can require its removal from the market.

The AOANJRR and its close links to the TGA are regarded as an international best practice model of the use of post-market data to monitor device safety.

Recent safety alerts

The TGA publishes alerts on its website when there is new safety information regarding therapeutic products.

Below are TGA safety alerts relating to medical devices published since the last edition of Medical Devices Safety Update.

Biomet titanium mandible implants: Biomet Australia has issued a hazard alert for two batches due to the potential risk of fatigue fractures.

Accu-Chek Spirit Combo insulin pumps: Roche Diagnostic Australia has initiated a recall for product correction due to the potential for high or low blood sugar events.

AcrySof Cachet phakic lens: This updates a previous safety alert. Alcon Laboratories Australia has issued a hazard alert and has withdrawn the lenses from the market.

Cognis Cardiac Resynchronisation Therapy Defibrillator and Teligen Implantable Cardioverter Defibrillator: This updates a previous safety alert. Boston Scientific has issued a hazard alert advising that additional models may experience premature battery depletion.

Claw and Claw II plates: Wright Medical Australia has issued a hazard alert regarding specific lots due to reduced strength and increased risk of failure. The sponsor is also recalling unused stocks of the affected lots.

Warning - incidents relating to use of walking frames as wheelchairs

Inappropriate use of wheeled walking frames as wheelchairs can lead to breakages and the potential for injuries.

The TGA has received four reports of incidents in which four-wheeled walking frames have broken during use.

TGA investigations revealled that misuse of these devices, specifically by using them as wheelchairs, was often the root cause of breakages.

It also appeared that, because they often related to misuse, such incidents were under-reported to sponsors and/or the TGA.

Many walking frames include a seat component, but they are typically not designed to withstand turning forces when loaded.

Using a walking frame as a wheelchair, even over short distances, can cause breakage and potential patient injury.

People using wheeled walkers (or responsible for their use) should be advised to:

  • read the IFU before use
  • avoid using damaged devices
  • ensure the seat is not overloaded
  • not use them as wheelchairs unless this use is specified in the IFU.

Health professionals and consumers are encouraged to report problems with medical devices.

For more information visit the Incident Reporting and Investigation Scheme page on the TGA website.

What to report? Please report adverse events, as well as near misses

The TGA encourages the reporting of any suspected adverse event or potential adverse event relating to a medical device. Adverse events can involve actual harm to a patient or caregiver, or a near miss that may have resulted in harm.

Some issues relating to medical devices that may lead to adverse events and prompt you to report include:

  • mechanical or material failure
  • design issues
  • labelling, packaging or manufacturing deficiencies
  • software deficiencies
  • device interactions
  • user/systemic errors.

Suspected adverse events or near misses can be reported directly to the TGA:

For more information about reporting, visit www.tga.gov.au or contact the TGA's Office of Product Review on 1800 809 361.

Disclaimer

The Medical Devices Safety Update (MDSU) is aimed at health professionals and is intended to provide practical information on medical device safety, including emerging safety issues. The information in the MDSU is necessarily general and is not intended to be a substitute for a health professional’s judgment in each case, taking into account the individual circumstances of their patients. Reasonable care has been taken to ensure that the information is accurate and complete at the time of publication. The Therapeutic Goods Administration gives no warranty that the information in this document is accurate or complete, and does not accept liability for any injury, loss or damage whatsoever, due to negligence or otherwise, arising from the use of or reliance on the information provided in this document.

© Commonwealth of Australia 2014

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For correspondence or further information about Medical Devices Safety Update, contact the TGA's Office of Product Review at iris@tga.gov.au or 1800 809 361.


Medical Devices Safety Update is written by staff from the Office of Product Review.

Editor: Dr Katherine Gray

Deputy Editor: Mr Aaron Hall

TGA Principal Medical Adviser: Dr Tony Hobbs

Contributors include: Dr Jorge Garcia, Mr Patrick O’Meley