When should we adopt new technology into our practices?

Abstract

What makes orthopaedic surgery so satisfying to practice? In my highly unscientific survey on this topic, the most common answer I hear is: “My patients usually get better.” The second is: “I enjoy using tools and new technology to make things as perfect as I can for my patients.” We need to make sure that we don’t mistakenly infer that the second answer causes the first. As importantly, we need to be mindful not to assume that the reason some patients don’t get better is insufficiently advanced surgical technology. Most people who undergo arthroplasty, for example, do well with surgery. Still, one in five patients who have total knee replacement are not satisfied with the result [1]. As the editor of a large, general-interest orthopaedic journal, I’ve lost count of the number of papers that begin with that unhappy 20%, and use it to justify the exploration of a new implant, navigation system, kinematic alignment approach, surgical robot, or other expensive, unproven tool. In general, I think that effort is misdirected. As far as we now know, differences in outcomes scores among generally well-performing implants are negligible or nonexistent [2], the odds of a new implant lasting longer than an existing one is hardly better than a coin toss [3, 4], and no well-designed study about a novel implant-alignment tool, ligament-balancing approach, or technology-driven innovation has made a dent in patient-reported outcomes or implant durability. The best such studies—systematic reviews, network metaanalyses, registry reports, and long-term follow-up studies of randomized trials—have found no differences at all that a patient might perceive [5–9]. I believe the main causes of patient dissatisfaction and persistent pain after major elective orthopaedic surgery are much simpler. For example, the proportion of patients in the United States with depression or anxiety is in the ballpark of 20% [10]; it’s pretty similar in Europe [11]. Incomplete management of depression and other manifestations of emotional distress (like anxiety disorders), as well as performing elective surgery on patients who are habituated to higher-dose narcotic analgesics—another known risk factor for persistent pain after full recovery—probably go a long way towards explaining why so many patients are not satisfied with their surgical results. They certainly make more sense to me than the fraction-of-a-degree improvements one might hope to get from a navigation system or a robot. Why, then, do bright surgeons (and good journals) sometimes take the bait, and believe that these new tools are worth using? Again, the answer is decidedly low-tech, if not downright unsexy: Human nature [11] as well as the common kinds of biases that cause us to overestimate our effectiveness in other areas [12] typically beset research about our newest tools. These include selection bias, transfer bias, and assessment bias, as well as the conflation of statistical significance with clinical importance (Table 1). All three of those kinds of bias are present, at least to some degree, in most observational orthoapedic research. And, importantly, they don’t offset one another. They work together to inflate the apparent benefits of new treatments and tools. Editors—people like me—need to help authors do a better job protecting readers from the misunderstandings and misinterpretations that these biases can cause. Until we address those sources of bias, which is best done using in the context of randomized controlled trials (RCTs) of adequate follow-up duration, and until we refocus readers attention on clinical importance (rather than mere statistical significance), we are likely to view new approaches more favorably than we should. It’s easy to be fooled, or to fool oneself. I know that I have. Some years ago, I published a comparative study of lessinvasive TKA [13]; I chose patients and controls immediately on either side of the changeover date from the conventional approach to the new one, so there shouldn’t have * Seth S. Leopold [email protected]