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Phys Ed: How Much Does Knee Surgery Really Help?


5 Star

Phys Ed: How Much Does Knee Surgery Really Help?

Our Review Summary

The author took the time to dig into many facets of the evidence and explain their meaning for someone considering ACL surgery. As this is a topic of interest to many readers, including "weekend warrior" recreational athletes, it was good that the reporter did not gloss over the uncertainties in the science nor the human factors that play into this decision. We suggest a few areas where we think the story could’ve been strengthened further.


Why This Matters

The researchers performed an important study involving a common surgical procedure that in many respects can be considered a quality of life (rather than quantity of life) procedure. Specifically, many individuals can function perfectly adequately in terms of usual activities without an anterior cruciate ligament. For those who are more physically active, surgical repair is thought to be superior to physical therapy-based treatments that do not include repairing the torn ligament. In the case of professional athletes who must perform at very high levels to succeed and maintain their livelihood, the decision to perform surgery is understandable. However, for an amateur athlete, whether high school, college, or otherwise, treating them the same as a professional athlete may be empowering to the patient, but may over-value the surgical procedure.

This study provides compelling evidence that for many patients, physical treatment alone without surgery leads to excellent outcomes in terms of pain, as well as function in both usual activities and sports-related ones. For someone who isn’t financially dependent on their knees functioning at an incredibly high level, a more conservative approach seems to be the way to go.

The follow-up question is whether long-term outcomes of surgical repair differ. We don’t know, but its hard to justify the upfront costs and small but real risks of surgery if the two-year outcomes are the same for the hypothetical differences in the long-term. Finally, of course, it is possible that the long-term outcomes may be similar or even better for those not having surgery.


Does the story adequately discuss the costs of the intervention?

Not Satisfactory

The author briefly mentions that the operation "can be expensive." A little more detail about the costs and economic forces would’ve been great. We consistently grade such vague references as unsatisfactory.

The question not raised is how the overall costs differ with the two approaches. The medical costs would include surgery, physical therapy, medications, etc over the 2 year follow-up period. Given the high cost of surgery, it is likely that a strategy with less surgery would be less costly overall.

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


(As noted, some of the measures in these studies can be considered either benefits or harms, depending on how you look at it.) 

This piece provides the absolute changes for each treatment group, and then tells us the key outcome: the results weren’t statistically different and demonstrated non-superiority. The piece reports the relative proportions of each group who tore their meniscuses. Qualitatively, it tells us about stability outcomes. The controversy surrounding the importance of these measurements is explored and sometimes implied; it would’ve been clearest for the author to explain (or wonder aloud) the meaning of increased mensical tears and instability in light of equivalent scores on the primary outcome. This story mentions that in the 2009 retrospective study, all subjects eventually developed similar and high levels of early-onset arthritis. 

The piece also provides some analysis of other outcomes, such as two "almost identical" results in the 2009 study. While quantified results are scant overall in this piece, that seems justified given that the comparisons between results often showed no statistical differences, which is clearly the important message. Of importance was the story’s exploration of the controversy surrounding the meaning of outcomes in stability and meniscus tears.

As mentioned in our introduction, this study raises the question of treating all ACL injuries as if patients are pro athletes. On that note, in an environment where we see pros jump at surgical therapy, one facet of the decision that would’ve been nice to raise is the recovery time. What are the outcomes, expectations, and/or trade-offs for getting back on the court sooner? The piece reports study outcomes 2 years after surgery. 

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


Several of the outcomes in this study straddle the line between benefit and harm (or lack of harm), so please see the "Benefit" criterion below, too. Overall, this story covers the authors’ key safety messages from the published NEJM article, particularly as they refer to the rates of adverse events between the two groups. The piece says in general terms that ACL surgery has risks like any surgery. It would’ve been better to include some more details. A mention, if not quantification, of specific risks would’ve added more balance to the discussion. The study itself did consider surgical and anesthetic adverse events in its analysis.

It also could have been clearer about the uncertainty about the lack of long-term outcomes. We don’t know how the two treatment groups will compare in terms of development of arthritis and future surgeries (e.g., more meniscectomies) farther out than 2 years. The challenge is that such long-term outcomes may be decades off in this young population.

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


We get a bounty of detail, about 8 sentences, describing the study design. We’re told its setting, number of subjects, population age, baseline behavioral characteristics, randomization procedure, treatment protocols, the number who crossed over, follow-up details, and the assessment technique. Then in the presentation of outcomes, they are compared between the treatment groups, and compared with the outcomes of a prior study. 

We’re also told the limitations of this research and of the controversies surrounding the impact of knee stability and meniscal tears. Furthermore, we hear that more research is needed about the long-term outcomes, the challenges of conducting large-scale randomized controlled trials (RCTs) on this question, and the mixed motivations for cross-over in the NEJM study.

It’s always great to see an acknowledgement of one of the key principles of evidence-based medicine: the superior quality of evidence from RCTs, the "gold standard" of medical research. It also identifies the 2009 study as retrospective, although readers may not be clear, despite all the puzzle pieces delivered in this story, that retrospective studies are generally speaking on a different tier than RCTs. A more precise distinction between the two studies and their outcomes wouldn’t have hurt.

One issue that the author could’ve spent more time on is the primary outcome, the numerical score that rated pain, function, and other measures. Composite outcomes have their own limitations and controversies, and more context and evaluation would’ve been helpful.

Does the story commit disease-mongering?

It doesn’t engage in disease-mongering, and we give it props for carefully identifying the populations who are more likely to tear ACLs, while citing a prevalence estimate among this group.
While not disease-mongering per se, we took issue with the early reference to the study subjects as "volunteers" who "agreed, rather bravely, to be randomly assigned." It’s more hyperbole than we think is necessary, almost implying that the subjects were crazy to take part in the study. If the medical community was sure that patients would be worse off if they were randomized to conservative therapy, the study wouldn’t be ethical, and the researchers wouldn’t have gotten approval to do it. It was approved because the medical community, as a whole, didn’t know the answer.

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


It cites the opinions of orthopedic surgeons, including one who seems clearly uninvolved in the NEJM study, and the author of the 2009 British Journal of Sports Medicine study. It also tells us the affiliations of interviewees who were involved and not involved in the two studies.

Note that the study publication discloses that the research was funded by a number of organizations in Sweden as well as Pfizer. As this wasn’t a drug study, we’re not sure what Pfizer’s interest were and point it out as an FYI.

Does the story compare the new approach with existing alternatives?

The piece was focused on two studies comparing a new approach, physical therapy plus the option of delayed surgery, to the so-called existing approach of early surgery.

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


It’s clear that ACL surgery and physical therapy are available.

Does the story establish the true novelty of the approach?


It’s obvious that ACL surgery and nonsurgical treatment aren’t novel approaches.

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


It’s clear the reporter did plenty of her own legwork.

Total Score: 9 of 10 Satisfactory


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