Post-market Monitoring of New Implants: Are Registries the Answer?

Robert B. Bourne, M.D., FRCSC
University Hospital
University of Western Ontario
London, ON

"When patients' best interests are looked after, everything else falls into place."

When ill, Canadians want the latest medical treatments including drugs, medical devices and new technologies, yet want to be assured that these treatments are safe, efficacious and in the case of medical devices, durable. Preclinical testing, randomized clinical trials and multicentre studies all help in assuring safety and efficacy, yet there remains a need for post-market surveillance to assure the public that a new treatment is durable and not associated with unexpected consequences1.

 

Total hip replacement (THR) is a good example of a new medical device whose introduction has been associated with 'the good', 'the bad' and 'the ugly' in terms of outcomes. 'The good' is that THR has a greater than forty year history, has benefited tens of millions of patients with end-stage hip arthritis and is durable with >90% ten year survivorship. 'The bad' is that several running changes to THR in efforts to improve clinical results (i.e. titanium femoral heads, poor socket designs, poor polyethylenes, ceramic head fractures and squeaking ceramic-on-ceramic articulations) have often provided inferior clinical results when compared to the implants which they replaced. 'The ugly' is related to THRs which were introduced, highly marketed, inserted in large numbers of patients, then recalled after many patients had been harmed by these devices (i.e. metal-on-poly surface replacements, 3M THR, BoneLoc bone cement, Sulzer acetabular sockets and the ASR and Durom metal-on-metal articulations). The question that we need to ask is, "How do we prevent these disasters by quickly identifying poor devices and identifying patients at risk?"

Randomized clinical trials (RCTs) are the gold standard when comparing one treatment to another2; however, in the case of total hip replacement or other medical devices, RCTs have several disadvantages. RCTs are costly and even when carried out on one device such as a specific THR, the results likely cannot be generalized to other THRs. In addition, by the time that ten or twenty year RCT results are available; most THR studies will be obsolete3. Thus, many believe that RCTs will have a limited role in the post-market surveillance of new medical devices such as THR.

As a consequence, national joint replacement registries are being increasingly relied upon to provide post-market surveillance of orthopaedic implants such as total hip and knee replacements. Registries allow the timely recognition of new treatment trends, identify implants with higher than anticipated failure rates and provide an early warning system to prevent unnecessary numbers of patients from being harmed by failing implant systems4.

National joint replacement registries are, in essence, part of a continuous quality assurance enterprise in which patients at risk are followed, good devices promoted, devices at risk identified and actions taken to limit the number of patients exposed to poor implants. Registries promote evidence-based clinical practice and influence health care providers by providing balanced, trustworthy clinical data.

In Canada, the Canadian Joint Replacement Registry (CJRR) is our national vehicle to provide post-market surveillance of new total hip and knee replacements5. Voluntary surgeon participation and the need for patient consent have been real impediments to the CJRR reaching its' full potential. Starting in April, 2012, encouraging developments will take place which should revitalize the CJRR. In April, 2012, Ontario and Manitoba will initiate quality assurance programs, whereby hospital participation in the CJRR is mandatory. These new programs will link hospital funding for THRs and TKRs with CJRR participation. A minimum data set (i.e. patient identifier, patient demographics, diagnosis, date of surgery, right or left side, implant catalogue and lot numbers) will be collected and sent by all hospitals performing THR and TKR surgeries in the provinces of Ontario and Manitoba to the CJRR. CJRR is housed in the Canadian Institute of Health information (CIHI), a not for profit organization funded by Health Canada and all the Canadian provinces and territories to keep tabs on the health of Canadians and our health care system. This CJRR/CIHI combined effort has many advantages including linkage to many other databases (i.e. mortality databases, emergency department care databases, etc.). Surgeons will be spared the time and effort of needing to enter patient, surgical and implant information for the CJRR, as this will now be performed by hospital personnel. If successful, it is anticipated that this model of quality assurance will be adopted across Canada.

In summary, post-market surveillance of orthopaedic implants is needed in Canada. There have been many examples of implants with higher than anticipated revision rates entering Canada. Our Canadian Joint Replacement Registry's time has come.

References

  1. Malchau H. On the importance of stepwise introduction of new hip implant technology. PhD thesis. 1995. Goteborg University, Goteborg, Sweden
  2. Laupacis A, Rorabeck CH, Bourne R.B., Feeny D., Tugwell P., Sim D. Randomized trials in orthopaedics: why, how and when? J Bone Joint Surg. 1989, 71A:535-543
  3. Corten K., Bourne R.B., Charron K.D., Au K., Rorabeck C.H. Comparison of total hip arthroplasty performed with and without cement: a randomized trial-a concise follow-up at twenty years of previous reports. J Bone Joint Surg. 2011, 93A:1335-1338
  4. Bourne R.B., Maloney W.J. , Wright J.G. The outcome of the outcomes movement. J Bone Joint Surg. 2004, 81A:633-640
  5. Bourne R.B. The Canadian Joint Replacement Registry: gaining momentum. COA Bulletin, 2008, 80:23-24
Key Summary Points
  1. Post-market surveillance is important to assure patient safety following introduction of new orthopaedic devices.
  2. National joint replacement registries are an ideal tool to provide post-market surveillance of new total hip and knee replacements.
  3. Mandated, hospital-generated data as part of a quality assurance program and removal of the need for patient consent would assure success for the Canadian Joint Replacement Registry.

 

 

 

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