Editorial: What CORR (R) Seeks From Papers About New Implants and Techniques

Orthopaedic surgery is a humane profession, but one that relies on physical technology. While greater attention has been given of late to more holistic, patient-centered approaches, many outside the field perceive orthopaedic surgeons as “tool people,” and some of us likely would endorse that characterization ourselves. It is therefore perhaps unsurprising that as a group, we remain overrepresented relative to other medical and surgical specialties in terms of relationships with the industry partners that design our implants, instruments, and devices [8]. In the only survey we could find on the topic, orthopaedic surgeons consistently ranked implant design, biomaterials, and instrumentation as more important to the success of an arthroplasty procedure than the patient, the team, or the surgeon [3]. Small wonder that our journals are full of articles evaluating the efficacy of the tools we use. But too often, journals allow authors to share overly enthusiastic messages too early in our collective experience with new tools, approaches, and devices. To be clear, Clinical Orthopaedics and Related Research® is interested in reporting on the performance of devices that are emerging as well as those that are in common use. But as we do so, we apply specific standards. Unintended consequences arising from well-meaning changes in practice have led to devastating public health harms in the past, and likely will do so again unless journals adopt and maintain thoughtful standards. Here are ours: First, all studies we publish that make claims about treatments must have a specific, usable clinical message that can improve patient care, practice management, or healthcare policy and resource allocation. This standard, of course, is not a new one for us. However, as we evaluate those studies’ claims, we will insist that studies evaluating a newer biomaterial or implant not support its adoption in clinical practice unless it is better in ways that patients can perceive than are available, well-performing alternatives that have been in use for a longer time. Of course, a different standard applies when assessing interventions for which there are no options or no good ones, and we’ll come to that standard in a moment. But where good and time-tested implants, biomaterials, surgical approaches, or tools exist, novel ones that are “as good as” or “comparable to” won’t make the grade if there is robust evidence demonstrating that the tried-and-true generally performs well. There are several reasons for this. The main ones are that new devices and biomaterials usually are more expensive than established ones, they generally come with learning curves during which patients may be harmed, and they always carry safety-related uncertainties associated with novelty. We’ve all seen too many devices and materials that look good early become problematic later on. Modesty calls on us to remember this when reporting on new things. We’ll hold authors to these expectations until the new device is found superior at sufficiently long surveillance periods as appropriate for the device in question, or until equivalence is shown at longer-term follow-up and the new device is less expensive. Of course, such guidelines will be applied thoughtfully. For example, there may be subsets of patients who don’t do well with a particular treatment even when most do; imagine a new biomaterial that can mitigate hypersensitivity reactions in patients known to be at risk for them, and the implant made of that newer biomaterial is as good as but no better than one made from the more-established biomaterial. In that instance, it might be sensible to recommend use of the new biomaterial when treating patients with hypersensitivity, but not recommend wider adoption beyond that. And occasionally, a new approach seems to work as well as more-established alternatives but is less expensive. In such circumstances, authors are free to describe a risk/reward proposition if they think the results justify doing so, and peer reviewers and editors here will consider those propositions in the larger context of the work. The same applies for new surgical technologies. For example, we’re past the point of knowing that joint replacements can be put in or tumors taken out using navigation systems and robotic assistance. The question now is, should they be, and if so, under what circumstances? In these situations, we need to be mindful of adding costs to an already-expensive system, one that seems mainly to enrich those who design the tools or improve parameters that patients are unlikely to notice. For example, the elements of THA that a robot might improve are clinically problematic in a very small percentage of patients. Because of that, the number needed to treat is likely to be so large as to make the systems cost-prohibitive if evaluated that way. Certainly, well-designed reviews suggest no benefits so far [6, 7], and thoughtful assessments have found that most technological innovations in mature orthopaedic interventions add little or no value [2, 9, 10]. Others call on us to remember how easy it is to be stung by unintended consequences—sometimes rightly called revenge effects—in the complex systems in which surgeons operate [11]. This observation is hardly new; an opinion essay in BMJ 30 years ago called “Designer Hips: Don’t Let Your Patient Become a Fashion Victim” made much the same point when the author concluded “in its current form the implant industry remains a haven for all the excesses of free enterprise” [1], an observation that could have been written yesterday. Sometimes new biomaterials, implants, and tools work out well. Highly crosslinked polyethylene comes to mind as the most important technological improvement implemented in orthopaedic surgery in the last several decades. The problem is that there have been many more bearing-surface and implant-design experiments that did not work out so well. Some have been genuine people-eating disasters. Guessing whether a new bearing material may work out well within the first few years after its release is a lost ball in the tall grass kind of exercise; sitting on the sidelines until we see long-term advantages generally has been the better play. And as a journal, we’re responsible to insist that authors steer readers toward making that better play. We note that there are some orthopaedic problems for which we have no established treatments, or for which the only available alternatives are unreliable. We will give authors writing about solutions to these problems more latitude to make their best case for their proposed solutions based on risk/reward tradeoffs. The same might be true in moments of genuine scarcity; for example, if war should result in the inability to obtain titanium [4], or if facilities that irradiate polyethylene for crosslinking are no longer willing to do so in high doses, one can imagine being forced to explore alternatives urgently. Surgeons and patients necessarily (and quite reasonably) are more accepting of novelty and risk if there is no treatment or no good treatment for a particular problem. But in the face of what has been termed moral hazard—a situation in which one person makes a choice that bears risk while someone else endures the harm if the guess proves wrong [5]—we will not be overly permissive when the opposite is true.