All right. So as Ed mentioned, there's a lot of continuing mystery about the best way to tree cubital tunnel. And because we don't have lots and lots of time to go into all of the evidence that's accumulated around this, which by itself is not very much, but there's certainly been a lot written about it, I'm going to just talk a little bit extemporaneously about how my treatment of this problem has evolved and things that have occurred to me while I've looked after this problem and have guided my personal management of it. And then I'm going to talk to you a little bit briefly about some research we're doing in this area to try to clarify how this problem should be treated. So I think we're pretty clear that in general, evidence has played not as big a role in the management of cubital tunnels as we might like. And practice is largely driven by experience, the experience of our mentors and then our personal experiences in practice. And in fact, it's a very difficult area to study with a rigorous methodologic approach for a number of reasons. First of all, we could probably spend a few hours just talking about our different views on what constitutes a case of cubital tunnel. The case definition is actually very elusive, whether or not you can make the diagnosis on the basis only of symptoms or a combination of symptoms and physical findings or a combination of symptoms, physical findings, and electrodiagnostic testing. This is a very controversial topic. So unless there's a clear definition of what cubital tunnel actually is, it's a very difficult thing to study, say, in the context of a randomized trial. There are also a lot of different surgical treatments. We're going to talk today about simple decompression or in situ decompression. Of course, there are anterior transposition procedures, both subcutaneous and submuscular medial epicondylectomy. And operationalizing a randomized trial to study all of these becomes a gigantic quagmire because when you have four treatments, it just makes doing a randomized trial largely infeasible. And many of the ones that have been published suffer from poor numbers and inadequate power. And finally, there's not a clear consensus on what a good result is. So for a patient that comes with a significant sensory complaint and also has intrinsic muscle wasting, if we do any of our surgical treatments and we solve the sensory problem, but the intrinsic weakness remains, should that be considered a good result or a poor result or an intermediate result? And there's actually, I believe, a lot of controversy and a lot of variation of opinion on what should be considered a good result. So these are all things that stand in the way of studying this using a cancer treatment type module where we would randomize patients' treatments and see what the results are. What evidence is available does suggest that simple decompression is probably the best treatment. And I won't go into a lot of detail, but there have been at least two randomized trials comparing simple decompression to either submuscular or subcutaneous transposition. While both of these studies were probably underpowered, they didn't show a substantial difference in the outcomes between these two treatments. And there's also been a decision analysis which quite clearly shows that the best overall strategy as a starting point, as a clinical policy, would be to start with simple decompression. I'll expand on that a little bit as we go forward. So I think it's pretty clear that when there's ulnar nerve symptoms that we believe are emanating from the cubital tunnel, it's because there's direct pressure on the nerve. And this is probably, at least in some measure, due to pressure from the ligament of Osborne. There's also a traction component, though, on the nerve with the elbow in the flexed position. And probably in most instances, there's a combined effect of both direct pressure on the nerve from the ligament of Osborne and the traction on the nerve from the flexed attitude at the elbow. So simple decompression as a treatment has certain advantages and disadvantages. And Ed's going to talk a bit more in detail about this. But obviously, the most enticing thing about the simple decompression is that it's easy. And it doesn't take very long. There's a minimum risk of complications, although complications can occur. And if it's going to be successful and alleviate the symptoms, usually recovery is very rapid because there's very little rehabilitation required. The disadvantage is that it may fail in an unacceptable proportion of cases. And unacceptable, it's a value-charged word. We may all have a different idea about what's unacceptable. But I think that the industry standard, if you look at the literature, is about 15% to 20% of failure of cases that truly are cubital tunnel. Having simple decompression and failing that is probably up to about 20% of cases. Medial epicondylectomy, I mean, again, I'm giving you my own personal advice here. But as far as the category of advantages, I can't see any for this procedure. And I think that this has, in large measure, become a procedure of historical interest only. But there may still be people that do it. I mean, the main disadvantages are things like risk of elbow instability or the potential for heterotopic ossification. So in most studies, medial epicondylectomy is really no longer considered one of the competing treatment options. Anterior transposition, if this is done in a submuscular way, it's probably the most definitive treatment because it alleviates both the compressive component, if we consider that an important part of the pathophysiology, but it also alleviates the traction component by placing the nerve on the anterior aspect of the elbow. The disadvantages, as I see them, at least in the way I perform this procedure, is that it requires a long wound. There's a certain amount of impairment related to lengthening the flexopronator origin to hold the nerve in the anterior position. And there's potential for elbow stiffness. So I think of these as all disadvantages balancing the advantage of the procedure being very definitive. So my personal current approach is to use a simple decompression. And I do an anterior transposition, a submuscular transposition, for cases that fail this initial treatment. So the main problem with that is that it may commit up to 20% of individuals to a second procedure if the simple decompression doesn't work. But the attractive aspect of it is, as I alluded to earlier, it avoids a much larger intervention, submuscular transposition, in a very large proportion of patients, but not all of them, maybe four out of five. So clearly there would be a lot of interest in being able to identify preoperatively what the right treatment would be. So to do a simple decompression in patients where the compressive element is the dominating pathophysiologic mechanism, and do an anterior transposition in those patients where the main problem is traction. Right now we take the approach that if we reduce the compressive part, then maybe the traction component won't matter as much. And that proves to be the case in up to 80% of people. However, identifying who would be best treated with a simple decompression and who would be best treated with an anterior transposition is a pretty tricky proposition. And I think what most surgeons do is do one procedure on everybody. And that's their standard of treatment for this problem. So with our current knowledge, can we distinguish direct compression from the ligament of Osborne from the traction component? And I would say that the answer to that is maybe. I don't believe that it is possible to do with electrodiagnostic testing. And disclaimer here, I think most people know that I'm pretty negative about electrodiagnostic testing in lots of areas, especially carpal tunnel syndrome, because it hurts. It takes time. It costs money. And it's far from definitive, particularly with cubital tunnel. I think it's inconsistently effective at even identifying whether or not there's a compressive neuropathy. I mean, in cases where it does show that there's clear compression at the level of the elbow, we can usually distinguish that or determine that clinically as well. So the likelihood that electrodiagnostic testing will be able to separate the patients who have a primarily compressive etiology for the ulnar nerve symptoms versus those that have mostly a traction component from those that have a combination of factors at play, I think the probability of that working out is pretty dim. But there might be a way to evaluate that clinically and try to come up with a decision-making based on clinical assessment only. And on that count, I'd like to tell you about a study that we're doing that Ed's part of. And that is a work we're doing with this simple decompression study group. This is a study where I've recruited 25 surgeons from across Canada and the United States to contribute cases that have a known outcome. These are cases that have just been treated with simple decompression. And the goal is to try to identify factors that we can identify in the clinic as predictive of success or failure of a simple decompression. Because if we could do that preoperatively, then we might be able to disqualify patients from having a simple decompression and advise them to have the larger procedure of an anterior transposition. So there have been a number of challenges with this project, which is currently ongoing. First of all, as I alluded to earlier, we've had some challenges in agreeing on the definition for the diagnosis of cubital tunnel, and everybody had their own ideas about that. We also faced some challenges in agreeing on the definition for a satisfactory outcome, as I alluded to earlier. There was disagreement on the appropriate period for follow-up to identify whether or not the result was successful or failed. And also, agreement on the clinical parameters that we should be looking at that we would typically obtain in the clinic to see which of these predicts a failure of treatment. Having said all that, we did come to agreement using the process of Delphi, which is a way of establishing consensus within a group, and we did come up with definitions for each of these factors, as I just described. Each center is recruiting approximately 20 patients in a ratio of 4 to 1 success to failure. So using our predefined definition of success, which was a pretty low bar, and any of you who want to discuss this with me afterwards, I'd be happy to explain what we used as a definition for success. But if everybody submits 16 cases of success and 4 cases of failure, what we'll end up with is 400 successful outcomes and 100 failures. And in regression modeling, you need to have about 10 occurrences of the outcome of interest, in this case failure, for each predictor in the model. So if we're successful with this, we should have the ability to predict up to 10 predictive factors that are clinically acquired factors that we see in the clinic every day on the history of the physical examination, and that should allow us to come up with a model that would predict who is likely to succeed and who is likely to fail with simple decompression. And we hope that in doing that, we'll be able to bring some light to this whole topic. So far we've accumulated about 200 cases, and we're hoping that by the end of this year we'll have all 500 collected so that we can go ahead and present this next year.

cubital tunnel syndrome

treatment

challenges

evidence

research