Over the last decade, most Canadian provinces have shortened wait times for many surgical procedures, including hip and knee replacement.

However, while provinces have poured resources into improving access, they have paid relatively little attention to measuring outcomes of these surgeries. The result, experts believe, is that some patients may be undergoing surgery when it is not appropriate for them, with lower chance of improvement and higher risk of complications.

Of particular concern is total joint replacement surgery for hips and knees. These surgeries are very effective when performed on older patients with significant pain and disability, but are increasingly being used in healthier, younger patients for whom they may not provide as much benefit. (Similar concerns have been raised about cataract surgeries performed on patients without significant visual impairment.)

While Canada does have a national joint replacement registry, participation is still voluntary in most provinces and it does not track patient reported outcomes, such as pain and disability reduction.

The failure of Canadian provinces to routinely measure patient reported outcomes raises important questions about whether patients are receiving sufficient information about the expected risks and benefits of hip and knee replacement surgery to make informed decisions about whether these surgeries are right for them.

Hip and knee replacement

Total joint replacement surgery is used to treat osteoarthritis, the most common joint disorder. Osteoarthritis occurs when the cartilage in a joint breaks down or wears away, so that bones rub directly on one another. It can be very painful and can cause serious disability.

There are a range of treatments for osteoarthritis, including medications to manage pain and physiotherapy to increase muscle strength and range of motion in affected joints. But when these treatments are not effective, hip and knee replacement surgery has been shown to provide significant relief from symptoms for many patients.

However, much of the research on the effectiveness of hip and knee replacement surgery has been done on patients over the age of 65. There has been significantly less research into the effectiveness of these surgeries for patients under 55 and over 85, says Robert Bourne, an orthopedic surgeon at the University of Western Ontario.

“The question of appropriateness isn’t whether surgery is effective in the target population,” says Bourne. “The question is whether surgery is as effective for the very young and the very old.”

Despite risks, join replacement on the rise among young patients

According to data from the Canadian Institute for Health Information (CIHI), the rate of patients aged 45 to 54 receiving knee and hip replacement has increased sharply over the last decade. Between 1997 and 2007, the rate of knee replacements for patients aged 45-54 more than doubled for males and more than tripled for females.

This growth is concerning, because evidence is beginning to emerge that the complication rates may be higher for younger patients undergoing joint replacement surgery. Data from Australia shows that the rate of revision for total knee replacement for patients under 55 is more than double that of older patients.

“Revision is the clinical term for re-replacement” says Cy Frank, the incoming CEO of Alberta Innovates Health Solutions, “It’s a disaster from everyone’s perspective when someone needs to have their surgery redone.” This is because the risks of revision surgery are much higher, he explains. These risks include serious infection and potentially fatal blood clots. Frank also emphasizes that the benefits are lower when a joint surgery needs to be redone. “When these surgeries need to be repeated, especially with knees, they’re much less likely to meet patients’ expectations,” he says.

It is not yet entirely clear why younger patients appear to be so much more likely to undergo early revision surgery, but Gillian Hawker, a rheumatologist at Women’s CollegeHospital, speculates that it may be linked to the desire of younger patients to maintain their active lifestyles. “We seem to be seeing more young people who are seeking out this surgery so they can continue to do high impact sports like hockey or skiing, but the prosthetics used in these surgeries were never designed to hold up to that kind of impact” she says

Even if younger patients do not require revision, research suggests they may nonetheless be at higher risk of being dissatisfied if their expectation was that the surgery would allow them to continue to safely play a high impact sport, when in fact it does not.

Also of concern is that younger patients may have less pre-operative pain and disability than older patients. As a result, they may see much less improvement than older patients, leading to greater rates of dissatisfaction. However, because Canadian surgeons do not routinely measure patient oriented outcomes like pre-operative pain and disability, patients must decide about whether to have surgery without all the information they need to make an informed decision.

Measuring patient reported outcomes

Canada has had a national joint replacement registry that collects demographic and clinical information about knee and hip replacement surgery since 2001. However, the registry is largely voluntary; in 2012 Ontario and British Columbia became the only two provinces to mandate participation. The largely voluntary nature of the registry means there is a risk of bias in the data, which limits its usefulness.

While CIHI makes raw data from the registry available on its website, this data is not in a form that is useful to either patients or surgeons. CIHI has not released an annual report based on registry data since 2009.

But perhaps most importantly, Canada’s registry does not measure patient reported outcomes, such as reduction of pain and disability or improvement in quality of life, which are the primary goals of hip and knee surgery.

There are many validated clinical tools available to measure patient reported outcomes, such as the Oxford Hip Score and the Canadian designed Western Ontario and McMaster Universities Arthritis Index. Wider use of tools like these, Hawker believes, would help provide patients with more complete information about whether joint replacement surgery is an appropriate treatment for their condition. If surgeons begin routinely measuring a patient’s pain and disability before surgery, this information can be compared  with other people who have had successful surgeries, so the patient and their surgeon can evalute together whether the patient is likely to benefit from surgery.

Hans Kreder, an orthopedic surgeon at SunnybrookHospital, agrees: “It’s important to measure quality from the patient perspective, not just process measures.” Kreder believes the main barrier at this point is cost. “It’s expensive,” he says, “contacting all those patients, getting them to fill out forms, that costs money.” But he believes technology is rapidly making such quality monitoring affordable. “Where at one time we would have had to follow up with patients over the phone, technology is such now that with appropriate consent and privacy measures, we can do this quickly and cheaply online,” he says.

Canada lags behind international jurisdications

Canadian provinces lag well behind jurisdictions like Sweden, the United Kingdom, and parts of the United States in measuring patient reported outcomes. Sweden has been operating a national knee replacement registry since 1979, and introduced patient reported outcome measures focusing on quality of life in 2002. Annual reports based on this registry are published online every year.

Stefan Lohmander, an orthopedic surgeon at LundUniversity in Sweden, says the Swedish registry has been invaluable in improving the quality of surgery across the country. “Surgeons and clinics get data on their outcomes so that they can compare themselves to national data,” he says. The Swedish registry has also allowed researchers to identify patient groups who are at higher risk of poor outcomes, including younger patients, says Lohmander.

Lohmander also credits the registries in Sweden, the United Kingdom and Australia with allowing for early identification of problems with certain implants and surgical techniques, such as the metal on metal hip implants discussed recently in the Globe and Mail.

The United Kingdom has also been collecting patient reported outcome measures since 2009. According to research published in the British Medical Journal, the United Kingdom is using these measures in “assisting clinicians to provide better and more patient centred care; assessing and comparing the quality of providers; and providing data for evaluating practices and policies.”

Challenges to effective measurement

International experience suggests that there are a number of important challenges to successfully integrate patient reported outcomes. Cost is one important consideration. While web technology can reduce costs in theory, in practice it appears that many patients are still more likely respond to paper based surveys.

Patient participation is also essential if patient reported outcomes are to be measured successfully. Older, sicker, and marginalized patients may find it difficult to participate in outcome measurement, particularly if such measurement is web-based.

Perhaps most concerning is the potential for misuse. Black writes in the British Medical Journal that patient reported outcome measures could be “used crudely to ration care.” While some patients will not benefit from surgery, he cautions that these measures have not yet been shown to accurately identify these patients pre-operatively.

While these and other challenges cannot be overlooked, they must weighed against the status quo in Canada, where surgery is more accessible than ever, but patients may not have all the information they need to make an informed decision.