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


When ill, patients 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 consequences.

The Good, The Bad, The Ugly

Total hip replacement (THR) is a good example of procedure for which the introduction of new medical devices has been associated with "the good, the bad and the ugly" in terms of outcomes.

  • The good is that THR has a greater than 40-year history, has benefited tens of millions of patients with end-stage hip arthritis and is durable with >90% 10-year survivorship.
  • The bad is that in an effort to improve clinical results, several changes to THR devices (ie, 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 that they replaced.
  • The ugly is related to THR implants that were introduced, highly marketed, inserted in large numbers of patients, and then recalled after many patients had been harmed by these devices (ie, 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 in a timely manner?"

Randomized clinical trials (RCTs) are the gold standard when comparing one treatment to another; however, in the case of THR implants or other medical devices, RCTs have several disadvantages:

  • Cost – RCTs are costly.
  • Generalizability – When an RCT evaluates only one specific THR implant, the results likely cannot be generalized to other THR implants
  • Obsolescence – By the time 10- or 20-year RCT results are available, most THR implant studies will be obsolete.

For these reasons, many believe that RCTs will have a limited role in the post-market surveillance of new medical devices such as THR implants.

A Role for National Joint Registries

As a consequence, national joint replacement registries are being increasingly relied on to provide post-market surveillance of orthopaedic implants such as total hip and knee replacements. A national joint replacement registry that collects data on all total hip and knee arthroplasties performed in a country includes:

  • Pooling of data to allow timely recognition of new treatment trends
  • Identification of implants with higher-than-anticipated failure rates
  • Provision of an "early warning system" to prevent an unnecessary number of patients from being harmed by failing implant systems
  • Evidence-based decision making

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.

The Canadian Joint Replacement Registry (CJRR) is Canada’s national vehicle for providing post-market surveillance of new total hip and knee replacements. Voluntary surgeon participation and the need for patient consent have been impediments to the CJRR reaching its full potential.

Starting in April 2012, encouraging developments will take place which should revitalize the CJRR: Ontario, Manitoba and British Columbia will initiate quality assurance programs that will man date participation in the CJRR. Hopefully, other provinces and territories will soon follow suit. Data entry will become a hospital, rather than surgeon, responsibility and will be linked to hospital funding for total hip and total knee replacements. Patient consent will no longer be needed, as participation in the CJRR will be considered an important quality assurance tool for use by both individual hospitals and the provincial Ministries of Health. Each hospital will submit a minimum data set to the CJRR, which includes a patient identifier, each patient’s demographic profile, the diagnosis, the date of surgery, whether a primary or revision procedure was performed, the side on which surgery was performed and the catalog and lot numbers of each implant used.

The CJRR will continue to be housed in the Canadian Institute of Health Information (CIHI), a not-for-profit organization funded by Health Canada and all Canadian provinces and territories to monitor the health of Canadians and their health care system. This CJRR/CIHI combined effort has many advantages, including linkage to other databases (ie, mortality, emergency care and blood use databases).

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.

Key Points

  1. Post-market surveillance is important to ensure 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 should ensure success for the Canadian Joint Replacement Registry.

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

Reprinted with permission from the Fall 2011 issue of COA Bulletin