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Medical Devices Safety Update, Volume 3, Number 6, November 2015
Medical Devices Safety Update is the medical device safety bulletin of the Therapeutic Goods Administration (TGA)
In this issue
Joint registry data offers insight into Australian orthopaedic implants
The TGA thanks orthopaedic surgeons, hospitals and health departments across Australia for supplying the data used in the Australian Orthopaedic Association National Joint Replacement Registry annual reports.
The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) annual reports offer insight into the performance of orthopaedic implants being used in this country, providing the TGA with vital data to underpin its monitoring of orthopaedic implant safety.
Eight implants with higher-than-expected revision rates were newly identified in the 2015 annual reports published on 1 October. These will be investigated in accordance with the TGA's processes.
Surgeons who have used particular implants are notified of the outcomes when the TGA undertakes regulatory action involving those implants, giving them the information they need to optimise patient care.
Sponsors send notifications directly to surgeons via hazard alerts. The TGA also publishes a range of web alerts and notifies relevant professional bodies.
Among many other functions, the AOANJRR provides population-based data on the comparative outcome of individual prostheses used in Australia. The 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 988,650 primary and revision hip and knee replacement procedures, with a procedure date up to and including 31 December 2014.
Several thousand implant combinations are tracked.
The registry also recorded 2517 elbow, 251 wrist and 1296 spinal disk replacement procedures from 2007 to 31 December 2014.
To date no elbow, wrist or spinal disk replacement implant has been identified as having a higher-than-expected revision rate.
The reports compare the performance of individual implants with all implants of that type and identify 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.
The eight newly identified implants consisted of five hips, two shoulders and one ankle. 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 revisions 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 surgeons who have used the implants via the hazard alerts and other alerts described above, and details of the action/intervention are published on the TGA website.
The TGA has contacted the sponsors of the eight newly identified implants requesting responses to the AOANJRR data.
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 reports list a total of 51 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 information indicates that the revision rate will decrease rapidly.
Apart from the newly identified implants discussed above that are still being assessed, implants with higher-than-anticipated revision rates fall into two other categories:
- identified before 2015 and still being used
- identified and no longer used.
Identified before 2015 and still used
There are 43 implant combinations in this category and all have been investigated using the TGA's processes:
- 23 are under observation
- 11 are the subject of market action (for example, cancellation, hazard alert, added contraindications, safety alert) following TGA intervention
- nine are still being investigated.
Some of the reasons why the TGA might decide to continue monitoring, rather than take regulatory action, are listed above.
Identified and no longer used
There are 74 implant combinations in this category. In most cases (42) they were identified after the implant combination had been withdrawn from the market or was no longer used.
In the other cases (32) the implants were withdrawn after TGA intervention.
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.
Reports highlight reprocessing issues
The TGA's medical device Incident Reporting and Investigation Scheme (IRIS) has recently received a range of reports relating to reprocessing and sterilisation of equipment used in operating rooms.
Some users have reported to IRIS that some reprocessing instructions don't comply with standards or that some devices are particularly difficult to clean.
Two recent reports have also highlighted the issue of potentially inadequate reprocessing when equipment is shared between different health facilities:
- 'Bone cement from previous use found on equipment (femoral impactor) on sterile field during knee replacement surgery. Contaminated items were removed from sterile trolley, area isolated from other equipment, scrub nurse's gloves replaced. Equipment had previously been used at a hospital outside the district.'
- 'Instrument set arrived at hospital contaminated with gross matter within the cannulated items. These items were completely obstructed with debris.'
In cases such as these, each hospital's sterilising unit is responsible for ensuring that equipment, such as trays and devices, are cleaned and sterilised appropriately after being used. When equipment arrives at the next place of use, that facility's sterilising unit needs to ensure the trays/devices are cleaned and decontaminated before use in that hospital.
Health professionals working in operating rooms need to be aware that any devices, such as screws, wires and prostheses, that have been implanted and then removed during an operation, must be discarded, not resterilised or reused.
When reprocessing reusable medical devices, such as instrument sets or loan kits, it is recommended that the manufacturer's Instructions for Use (IFU) are followed to avoid the potential for the device being contaminated or not sterilised and disinfected sufficiently.
Manufacturers of medical devices:
- are responsible for providing validated IFU and reprocessing instructions
- are required to demonstrate that the device (including documentation supplied with the device) complies with TGA regulations which stipulate the required safety and performance characteristics
- may follow a standard to demonstrate compliance with these regulations, however this is not a mandatory requirement.
'Mild' hyperbaric chambers cancelled after advertising complaints
Public complaints about therapeutic goods advertising triggered a TGA investigation that led to the cancellation of three portable 'mild' hyperbaric chambers from the Australian Register of Therapeutic Goods.
The TGA's Medical Devices Branch recently completed a post-market review of portable 'mild' hyperbaric chambers after receiving complaints regarding the large range of therapeutic claims being advertised in relation to these devices.
'Mild' hyperbaric chambers are soft-sided enclosed units into which a patient is placed and subjected to higher-than-normal air pressure. The term 'mild' differentiates them from similar hard-bodied units which operate at higher pressures and are used to treat certain illnesses, such as decompression sickness in divers.
The TGA identified three devices listed on the Australian Register of Therapeutic Goods (ARTG) for review and each of these made therapeutic claims. In all three cases, clinical evidence could not be provided by the sponsors to substantiate the therapeutic claims made in relation to the devices. Two of the ARTG entries were subsequently cancelled by the TGA and one by the sponsor.
Recent safety alerts
Below are TGA safety alerts relating to medical devices published since the last edition of Medical Devices Safety Update.
VAIOS Total Shoulder Replacement System: Hazard alert - higher-than-expected revision rate. Orthotech ceased supply of this device after its cancellation from the Australian Register of Therapeutic Goods.
Prism Medical P300 and C300 ceiling hoist: Recall - potential for user injury as a result of device breakage. Rehab Assist is recalling all of these hoists manufactured before 8 June 2015.
Duracon augments tibial wedge implants - used in knee replacements: Hazard alert - potential for post-operative infection. There is potential for Duracon augments tibial wedge implants to puncture the packaging before use.
Shuttle Discovery Seat: Recall for product correction - potential for user injury when used with a stroller frame that has tie-down fittings for securing the device within a vehicle.
Silimed medical devices (all - including breast implants): Safety advisory update - particles provisionally identified as silica and cotton. The TGA is undertaking testing to investigate particles on the surface of implants.
SeleXys TH+ and TPS acetabular shells used in hip replacements: Hazard alert - higher than expected revision rates. An analysis identified early loosening/lysis as the reason for the higher rates of revisions.
St Jude implantable devices when used with the Merlin@home transmitter: Hazard alert update - additional issue that can result in an unintended device software reset.
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:
- online at Report a problem
- by emailing email@example.com
- by mail to IRIS, TGA, PO Box 100, Woden ACT 2606
- by fax to 02 6203 1713.
For more information about reporting, visit www.tga.gov.au or contact the TGA's Medical Devices Branch on 1800 809 361.
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 2015
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For correspondence or further information about Medical Devices Safety Update, contact the TGA's Medical Devices Branch at email@example.com or 1800 809 361.
Medical Devices Safety Update is written by staff from the Medical Devices Branch.
Editor: Dr Pamela Carter
Deputy Editor: Mr Aaron Hall
Acting TGA Principal Medical Adviser: Dr Tony Gill
Contributors include: Dr Jorge Garcia, Dr Amanda Craig and Mr Shawn Hazel