All right, so our next session is on nerve, and it's my pleasure to introduce Richard Gelberman to give us some background information on the science of surgical choices for the ulnar nerve. Well, thank you, Chuck. It's a pleasure to be here. So my charge this morning is to provide the background with regard to what kind of operation you're going to do for cubital tunnel syndrome. And I have my bias, but I'm going to try to present the science that's important with regard to making that choice. And so I'm going to point that these are my royalties, so that's for your information. And I'm going to talk about a few scientific studies and anatomical studies that I think help inform your choice. And the first question is, why does this syndrome occur? And if you're going to treat it effectively from the operative perspective, you're going to pay attention to why it happens and address those factors that are most germane. So there are a couple scientific and anatomical studies to which I'll refer, and the first is this one. This is a study done by Patel, reported in JSES, in which they used interpolated slices, one millimeter interpolated slices MRI, to study the ulnar nerve in varying degrees of elbow flexion to see just what happens when you extend the elbow and then flex it maximally. And if you look up on slide A and B, you see the elbow from the lateral side. This is medial epicondyle and olecranon, medial epicondyle and olecranon. You see that with the elbow in full extension, the ulnar nerve looks almost redundant, filling the canal. And as you progressively flex the elbow, it drapes over the posterior aspect of the medial epicondyle. Seen from the back, you see the ulnar nerve here with the elbow in extension, and here with the elbow in flexion. And apparently more stress on the ulnar nerve with the elbow in flexion. Related studies looking at cubital tunnel area show that when you extend the elbow, you have pressures, the cross-sectional diameter of the cubital tunnel is here, and when you flex it, it is far reduced. There's a mean decrease in cubital tunnel area from extension to full flexion of 42%. If you look at just the ulnar nerve and did a cross-sectional diameter of the ulnar nerve with the elbow in extension in a normal individual, and then in full flexion, you'd find that the ulnar nerve cross-sectional area from extension to flexion decreases by 36%. And if you took a ratio of the ulnar nerve to cubital tunnel diameter, you'd find that both decrease significantly, and there's no significant difference in the drop in cross-sectional area between the cubital tunnel and the ulnar nerve. We did a study to determine, well, just what happens to the nerve as you flex the elbow with regard to pressure, and how close do these pressures get to the critical pressure threshold for the ulnar nerve and for nerve function. And so what we wanted to do is not disturb the anatomy at all. We didn't want to cut the arcuate ligament, cut the FCU. We wanted to leave it intact, and we said, well, how do we do that? So we used a slit catheter. We inserted it into what we thought was a cubital tunnel, and then we confirmed our position with ultrasound, and we made sure that on two views, the catheter was either within the nerve, as you see here, or was in the extra neural space within the cubital tunnel. We thought we could answer a couple questions if we could accurately measure those pressures. And then we progressively flexed the elbow from full extension to full flexion to see what happened to those pressures. And this slide shows two things. It shows that actually the lowest pressures within the cubital tunnel are between 30 and 70 degrees of elbow flexion, with the absolute lowest pressures at 50 to 60 degrees of flexion, lower than full extension, which was interesting to us. And then second, it showed that intra-neural pressures begin rising at 70 degrees of flexion, that extra-neural pressures begin to rise at 100 degrees of flexion, suggesting that tension is a significant factor with regard to raising pressure within the ulnar nerve. This further confirms that concept in that we measured pressures within the ulnar nerve and the extra neural space four centimeters proximal to the cubital tunnel, and then we flexed the elbow. What we found was that ulnar nerve pressures as you flex the elbow rise significantly, albeit at a little later stage, four centimeters outside the cubital tunnel, again suggesting that there's significant tension on the nerve as you bend the elbow. So how do we use these data in determining what to do clinically, both non-operatively and operatively? Well, we have to consider that there are two factors. Now of course the limitations of these studies, that they're done in normal cadaver, they're not done in patients with cubital tunnel syndrome, and so there may be other factors involved. But we believe, at least at this point in 2014, that there are two factors you have to address, and one is compression and the other is neural tension. Now having said that, how many people in the audience have had symptoms of cubital tunnel syndrome? Please raise your hand. Okay, so that's nearly 100% of people in the audience. How many of you had surgery for cubital tunnel syndrome? There are three unfortunate people in the audience. So it's very common, and we know why. And so the question is, how do you approach it? So my physical exam and my decision-making process in 2014 involves the following. I start with the cervical spine, active range of motion in three planes, Sperling's maneuver, and then I actually palpate the anterior cervical triangle and then try to elicit a tunneles in the cervical triangle, which is helpful. I tap pretty hard, as my fellows will attest, and the patient tells me whether they have a positive tunnels. I'll examine the elbow, and I'll particularly look for a subluxable on a nerve, flexing the elbow to see if it pops out of the groove. That's very important, in my view. I'll do a tunnels sign at the cubital tunnel, and then a flexion-compression test where I'll flex the elbow maximally, press over the nerve, and see if it reproduces symptoms. Finally, I'll look at the hand. I'll examine each of the ulnar nerve and innervated intrinsics in the FTP little. I'll look for a Wartenberg sign, and I'll examine, I'll evaluate 2PD on all patients, and I'll record it. So I think that's really important, to record all these findings. And then while I don't always get electrophysiological studies for patients with carpal tunnel syndrome, if I'm considering operative treatment for cubital tunnel syndrome, I get electrophysiological studies 100% of the time. And what I'm looking for is a 30% to 50% reduction in conduction velocity. So if normal for your laboratory is 60 or 61 meters per second, I'm looking for something below 45 meters per second to make that diagnosis and to decide on operative treatment. What do I do for non-operative care? For all of you who are in the audience, you all found a way to deal with your symptoms. You didn't undergo surgery, so what did you do? So here's what I do, but you can tell me whether this is right or not, because you've all dealt with the issue, as I have. I had cubital tunnel syndrome, and it doesn't bother me any longer. I avoid overhead weights because of those patients who get triceps compression of the ulnar nerve. So in particular, I tell them to avoid any triceps exercises, particularly for weightlifters. Number one, there are four factors. Number two, I avoid direct pressure on the ulnar nerve. I tell them to avoid placing their elbow on the console of their car, or if they're in a movie, avoid that flexion. Try to develop a habit of avoiding acute flexion. And that's number three. Develop a habit of maintaining the elbow in approximately 45 degrees extension. You don't have to walk around with your elbow straight, but just don't do this all the time. And so that's helpful. And then finally, use a nocturnal splint. Now the splint on the right there that you see is not a popular splint. We used it for years until patients began telling me, we really don't like this. It's a rigid splint. They don't like it. So what we devised was subsequently this pillow splint. This is actually a towel that's wrapped around the elbow, and it's brought together with duct tape. I think Dr. Goldfarb has patented it, so you can talk to him about it. It's quite attractive. But it is helpful, and they like it. And so this is what we use for patients, particularly at night. We tell them to sleep in this splint to avoid. Many patients sleep with their elbows flexed to avoid that position of marked flexion. So what do we know about nonoperative treatment? As you see in the audience today, the majority of patients with myocubital tunnel syndrome respond to nonoperative treatment. I do the four things I reported on here, and most of them do respond. The best study to date suggests that 50% to 70% of patients with moderate and 100% of patients with severe compression, that is atrophy and increased 2PD, will require operative treatment. My own approach is to treat those patients operatively. Peter Stern, patient comes in with increased 2PD and atrophy. Do you always operate on those patients, or do you treat them nonoperatively? It depends on what their complaints are. He said it depends on their complaints. They're complaining of numbness and tingling and weakness. If I didn't think the nerve was shot, I probably would operate on them. I'd do a simple decompression, assuming normal. Okay, and that's pretty much the treatment. If they come in and they're symptomatic and they have severe findings, we feel the same. So with regard to operative treatment, what's new? What do you have to think about? Well, the most recent interesting studies want to know what happens if you devascularize the nerve, what happens to its function, and what happens to its intrinsic properties. And we know the answers to those questions in 2014, and I'll report them briefly. First, a study by Yamaguchi and JSCS a number of years ago pointed out the three vascular radicals to the ulnar nerve. The major one is the inferior ulnar collateral, of course, it's beneath the medial undermuscular septum, just proximal to the medial epicondyle, and supplies the ulnar nerve in this region. But there are also radicals from the superior ulnar collateral that anastomose with the IUC and the posterior ulnar recurrent. It's a major vessel. You can identify it. You can protect it. But it does supply a significant portion of the nerve. Mansky did a study where he looked at the regional blood flow to the ulnar nerve. He interrupted these radicals in monkeys and found that there was a significant decrease in ulnar nerve blood flow lasting for three days after stripping the nerve of its vascular supply. But he didn't know what the significance of that was. We subsequently did a study where we transposed the nerve in animals and then looked at the material properties of the ulnar nerve just after transposing it, nothing else. And what we found was, interestingly, there were significant biomechanical changes of the nerve. In essence, the nerve spot-welded its scarred for that entire region of transposition, irrespective of whether you treated it with early motion or immobilization. The nerve did not seem to respond to early motion like tendon does. It scarred just as badly with early motion as it did with immobilization. So does maintenance of the vascularization of the ulnar nerve improve things? If you were able to maintain these vessels, would that make it better? And there are two studies to which I'll refer. One was by Nakamura. I think this is worth reading. It's a very good study. Thirty-six patients in Japan divided into two groups, the vascular pedicle sparing group and the artery ligation group. And then they studied them by Doppler intraoperatively in three, six, and 12 months. And they found that they could preserve the extrinsic vascular pedicles. And if they cut those arteries, that nerve was relatively ischemic compared to those that were maintained intact. So with that in mind, I won't give you the answer as to which of these procedures I prefer. I'll just say that the presenter who's most likely to be a Pirates fan is likely to be the person who will talk about the things that I like to do, and among the next presenters. There are two that may be Pirates fans, actually, but the one who is more likely to be a Pirates fan. So my patient for the panel is the following, a 45-year-old painter who has numbness and tingling in the ring and little fingers for six months, weakness and a positive Wartenberg sign, no atrophy, two-point discrimination is five millimeters. This patient has failed nonoperative treatment for four months, continues to be symptomatic. His nerve conduction studies are 35 meters per second in a laboratory where 60 is normal. And we've decided on operative treatment. Thank you.

Richard Gelberman

surgical choices

ulnar nerve

cubital tunnel syndrome

non-operative treatment options