The MITCH TRH System is a metal-on-metal hip replacement system consisting of two components.
These components include:
- the MITCH TRH modular head or resurfacing femoral head; and
- the MITCH TRH acetabular cup.
These components are used in different combinations to carry out either hip resurfacing or total hip replacement.
When used in conventional total hip replacement, the MITCH modular head is used with one of several different brands of femoral stems.
The TGA has, with data sourced from Australia's National Joint Replacement Registry (NJRR), identified that the MITCH TRH modular head when used in combination with the Accolade and several other femoral stems has a higher rate of revision surgery than the average for total conventional hip replacements.
The MITCH TRH modular head has been cancelled from the Australian Register of Therapeutic Goods and it cannot be used in Australia.
Information for patients
If you have a MITCH TRH modular head as one of the components in your hip replacement, please contact your implanting surgeon to arrange your next scheduled review appointment, if you don't already have one.
Information for orthopaedic surgeons
Stryker, the sponsor in Australia, has written to all orthopaedic surgeons who have implanted the MITCH TRH modular head and advised them that:
- At the time of follow-up, surgeons should ensure that they inform the patient about the MITCH TRH modular head and advise them to return if they are experiencing any problems.
- It is recommended that surgeons follow up patients who have total conventional hip replacements with MITCH TRH acetabular components more frequently than they normally would, and that consideration should be given to including soft tissue imaging such as ultrasound and/or MRI and cobalt and chromium blood tests as part of the follow up process.
This recommendation is in line with international advice such as that published by the United Kingdom Medicines and Healthcare products Regulatory Agency (MHRA).
Information for all health professionals
Patients with any hip replacement should be followed up by the implanting orthopaedic surgeon if possible, particularly if the patient complains of pain and other symptoms associated with their hip implant and surgery.
Technical information
In Australia, there have been 729 combinations of the MITCH TRH modular head and various models of femoral stem and 37 have been revised, which is a cumulative rate of 4.3% at three years.
Of the 729, there were 400 combinations of the MITCH TRH modular head with the Accolade femoral stem and 24 revisions have occurred, which is a cumulative revision rate of 5% at three years.
It is important to note the following:
- Review of the NJRR data reveals that the revision rate for the Accolade Femoral Stem when used with other (non-MITCH TRH) acetabular cups is in line with that of all other conventional total hip replacements.
- The MITCH TRH System when used for hip resurfacing has a low revision rate compared to other total resurfacing hip replacements.
Reporting problems
Consumers and health professionals are encouraged to report problems with medical devices. Please refer to the TGA Internet site for more information on the TGA Incident Reporting and Investigation Scheme (IRIS).
You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medical device.