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Careful look at tradeoffs involved with double knee replacement

Why Double Knee Replacement Might Be Best

Our Review Summary

double knee replacement

A patient profiled in this WSJ story awaits double knee replacement. Credit: Pete Hausler/The Wall Street Journal

This installment of the Wall Street Journal’s “Informed Patient” feature looks at the risks and benefits of bilateral knee replacement surgery (in which both knees are replaced during the same operation) as compared to staged knee replacement surgery (in which the knees are replaced during separate surgeries, usually months apart). While the story finds that it can be less expensive and time-consuming to have the bilateral knee replacement, it also reports that bilateral replacement surgery may pose increased health risks for patients.

The coverage overall is thorough and gives readers a good sense of the tradeoffs involved with each approach. The inclusion of more details about the “better outcomes” achieved in some studies of bilateral replacement would have been a valuable addition to the piece.


Why This Matters

A 2012 paper in the Journal of Bone & Joint Surgery reported that the number of knee replacements performed each year in the United States increased by 134 percent between 1999 and 2008, with 615,050 replacements done in 2008. And the number appears to still be on the rise, with the CDC reporting that 719,000 total knee replacements were performed in the U.S. in 2010. And no surgery is without risk. The Mayo Clinic notes that risks associated with knee replacement include infection, blood clots, heart attack, stroke and nerve damage. Some of these risks are life threatening and there’s a small, but real and unavoidable, fatality rate associated with knee replacements. In addition, the surgery can be costly. The website Healthline estimates the average cost of a total knee replacement to be $49,500 — or $57,000 if it requires a hospital stay. The fact that knee replacements are not uncommon, coupled with the presence of significant costs and health risks, makes it a subject worth reporting on. And if bilateral knee replacement is becoming more common (as reported in the story), and it affects both the costs and the risks, that’s worth discussing.


Does the story adequately discuss the costs of the intervention?


This is an essential part of the story, since cost is presented as one of the most significant benefits of performing bilateral knee replacement. The story cites a 2013 study that “estimated the cost of bilateral surgery at $43,401 compared with $72,233 for two separate surgeries staged over time.” One addition that would have made the story a bit stronger: since many patients requiring knee replacement surgery are older adults, it might have been useful for readers to know the extent to which Medicare might defray related costs. Still, the story tackles cost head on, and gets a solid Satisfactory here.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

As mentioned above, one of the most significant benefits of the bilateral surgery is cost. However, there are others — such as the fact that a patient only has to be anesthetized once, and will likely spend less time (overall) in the hospital. The story says that the 2013 study where it got its cost numbers “concluded that bilateral surgery is more cost-effective with better outcomes for the average patient than staged procedures for two knees.” We italicized the “with better outcomes” part, because that’s the sticking point. What does it mean? In order for readers to make sense of a term like “better outcomes” it needs to be both clearly defined and quantified. On a side note, it would be great if the story linked to the relevant 2013 study.

Does the story adequately explain/quantify the harms of the intervention?


The story is pretty clear on this, noting early on that “recent studies have found increased rates of complication such as blood clots that travel to the lung, an increased need for blood transfusions, and a higher risk of death with the bilateral procedure.” Later the story refers to two different studies. One, published earlier this year, found “increased overall complications and risk of subsequent surgery within 30 days” for patients who had the bilateral replacement. The other, published in 2014, found that “bilateral patients were at increased risk of both minor and major in-hospital complications as well as death.” Again, it would have been great to include links — or citations — for the relevant studies.

Does the story seem to grasp the quality of the evidence?


We’ll give the benefit of the doubt here, as the story does a reasonably good job of summarizing the broad outlines of evidence from several recent studies. In that respect it’s more illuminating than stories that rely on a single study while ignoring the bigger picture. But the story could have been more thorough. In discussing a recent Journal of Arthroplasty study, for example, the story states that researchers found “no significant difference in the rate of complications including infection, hospital re-admission, or death. But bilateral procedures were associated with increased overall complications and risk of subsequent surgery within 30 days.” It’s unclear to us what this means. How can there be “no significant difference in the rate of complications” but also “increased overall complications”? The description of a 2014 study is also somewhat vague, really only telling readers how many patient claims were reviewed (this was the study that found an increased risk of both complications and death). And the story doesn’t really tell readers anything about the 2013 study (where it got its cost numbers and the “better outcomes” reference).

Does the story commit disease-mongering?


No disease mongering here.

Does the story use independent sources and identify conflicts of interest?


The story talked to multiple sources and clearly identified those who played a role in studies that were cited in the story.

Does the story compare the new approach with existing alternatives?


The story is, in effect, all about comparing alternatives — bilateral versus staged knee replacement. One thing that’s not made clear anywhere in the story is whether the knee replacements in question for any or all of the studies were total knee replacements, partial knee replacements, or both. Are there differences in cost? Benefits? Risks? That would have been useful to include.

Does the story establish the availability of the treatment/test/product/procedure?


It was made clear that both bilateral and staged knee replacement surgeries are fairly common and widely available. Similarly, it was made clear that some surgeons refuse to perform bilateral surgeries, or will only perform them for patients that meet fairly stringent criteria.

Does the story establish the true novelty of the approach?


The story notes that, as of 2010, approximately 6 percent of patients who get both knees replaced have bilateral surgery — up from 4 percent in 1999. So, the technique is not new, but there has been some growth in the use of the surgery as younger and healthier patients become candidates for knee replacements — and the story establishes this. The story could have been clearer about the fact that this technique has been routinely used even longer than that. (Reviewer Jim Rickert can recall doing bilateral replacements not infrequently as far back as the 1980s.)

Does the story appear to rely solely or largely on a news release?


The story does not appear to be tied to a news release. And, given the number of patients and doctors interviewed, the story goes well beyond what would be included in a news release anyway.

Total Score: 9 of 10 Satisfactory


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