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Controversial Topics in Hand Surgery - Hand Fellowship Debate Series - Cubital Tunnel with Intrinsic Wasting
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Controversial Topics in Hand Surgery - Hand Fellowship Debate Series - Cubital Tunnel with Intrinsic Wasting
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JEFFREY GREENBERG: Welcome to the next edition of the Hand Fellowship Virtual Debate series. This has been really a great series that Jerry started and Jerry has another webinar right now, so I'm going to do the intros and then turn it over to Fraser. So this is more of a traditional one like we started. Last week, we had a cocktail hour and then some faculty presentations.
JEFFREY GREENBERG: So we're going to go back to the fellow presentations and these have been, I think, a great experience for the fellows. They've done tremendous jobs with the presentations, given us really good presentations, and there's been great faculty input and participation in the discussion at the end and I truly anticipate this will continue tonight.
JEFFREY GREENBERG: So our team is going to start off with Dr. Leversedge as our moderator, formerly of Duke but now then he has moved to Colorado and seen the greener pasture, so he'll be able to ski and do some things he couldn't do well in North Carolina. And the debate is going to be between the team from Brigham and women's team from MGH and team from the Ohio State University.
JEFFREY GREENBERG: So with that, I will turn it over to Dr. Leversedge to start the program.
FRASER LEVERSEDGE: So there we go. Can everyone see that OK, Warren? Yep you're good. Perfect great. Well welcome, everybody, and thanks to everyone for participating and obviously to Warren and Jerry for this outstanding series.
FRASER LEVERSEDGE: This actually, this slide is from a top of Mount Baker, which overlooks Seattle. It was in Jerry's honor, overlooks my hometown of Victoria, Canada. And tonight, we're going to be looking at the management of chronic cubital tunnel syndrome with intrinsic atrophy and I think we all know this can be a challenging issue for restoring function and sensibility to the hand.
FRASER LEVERSEDGE: And I'd like to introduce our team. We'll introduce them individually as they get to their talks. We have, as Warren mentioned, a team from Brigham, Mass. General and The Ohio State, and we'll look forward to hearing from them. This is our format. We'll have a presentation from each of the Fellows for their respective charges.
FRASER LEVERSEDGE: Insight to nerve decompression, anterior transposition and anterior transposition with the addition of an anterior interosseous nerve to ulnar nerve transfer in the distal forearm. And then we'll have hopefully some time to discuss with within amongst the faculty in terms of the case and some some other challenges that come up along the way. So typically, the challenge for us is that there are several methods for many of the conditions we manage, and particularly the ulnar neuropathy at the elbow.
FRASER LEVERSEDGE: Each of these methods requires careful attention to detail, probably nothing more than the ulnar nerve at the elbow, both in terms of a preoperative nerve assessment and meticulous surgical technique to gain ultimately great outcomes. But we have to recognize that not all ulnar nerve pathology is the same, and this is where our challenges that we don't want to put things into buckets and treat all of the ulnar nerve conditions with one procedure
FRASER LEVERSEDGE: and I think that's going to be the important take home message at the end. There are many pitfalls that hopefully come out from our various discussions tonight when we have to recognize differential diagnoses and not so much part of this discussion, but I encourage the Fellows to really consider this. And then obviously with intrinsic atrophy, the influence of time really has to be considered for ultimately for nerve recovery.
FRASER LEVERSEDGE: And at the same time, the way that we manage the ulnar nerve, we have to remember that it's ultimately cranky and we have to be aware that it has a very low threshold for being insulted. This is our index case for this evening. This is a fairly straightforward, nothing hidden or surprise. 62-year-old right hand dominant accountant, an avid guitarist who's noted for years of progressive numbness to the small finger in particular with subjective weakness, medial elbow pain on clinical exam, a positive ulnar nerve flexion compression test and intrinsic atrophy
FRASER LEVERSEDGE: as you can see with the accompanying photograph. Radiographs of the elbow and wrist are without anything substantial in terms of abnormal pathology. And this is our nerve study that was obtained and sent to the clinic with the patient. You can see here the nerve study to the first dorsal interosseous abnormal. And then our EMG study demonstrates that the first dorsal interosseous two plus fibrillations, positive sharp waves and then reduced UAP's.
FRASER LEVERSEDGE: Just to add to our discussion, the pronator quadratus was all within normal limits. I think as we consider these three options, we have to consider the pluses and minuses and sometimes you can have a great day skiing on the downhill and sometimes once in a while you run into an avalanche and it's not so, not so pleasant. And so as we want to think about our our topics, recognize that there are some shortfalls of the insights, nerve decompression, as Ryan Calfee and others have shown us the potential for ulnar nerve hypermobility, you can see this in this patient undergoing a revision case for an in situ nerve decompression.
FRASER LEVERSEDGE: You look carefully here, you'll see the subtle instability coming now and you can see what happens and why the patient was symptomatic when that occurred. You can see the changes here at the wrist, which is demonstrating and not so happy ulnar nerve. There have been several studies that have looked at the potential re-operation rate and actually, Dr. Blazar, one of our faculty this evening, would suggest that it incites your nerve decompressions have a lower re-operation rate than anterior transposition.
FRASER LEVERSEDGE: Doug Hutchison, the University of Utah suggests that perhaps there's a higher re-operation rate in nerve decompressions not necessarily the same cohort of patients, obviously. Ulnar anterior transposition also has its relative difficulties. You can see here perhaps surgical technique misleading the ultimate outcome through a small incision and you can see here the ulnar nerve is lost,
FRASER LEVERSEDGE: it's anteriorly transposed position. But a careful look shows us that they've missed out on the principles of managing the ulnar nerve, leaving the intermuscular septum intact and perhaps not decompressing the nerve appropriately for its anteriorly transposed position. Submuscular transposition we think we used to think of as a panacea, not always gliding below the transposition site, below the flexor-pronator origin, and then the intramuscular and submuscular transposition which sometimes can be led astray with this serpentine ulnar nerve, which you can see here, is probably multiple points of tethering.
FRASER LEVERSEDGE: And not to be outdone, we know that there's been there's advocates on this panel for distal ulnar nerve or anterior interosseous nerve transfer to the ulnar motor nerve at the level of the wrist. And again, there's some good papers. I won't, I won't take Amy's thunder here with a really nice review article and their review of their clinical experience using the super supercharged endocyte transfer.
FRASER LEVERSEDGE: But we have to critically drill down on the data and this is a paper from Steve Moran and their group at the Mayo clinic and from Toronto, Canada, which in the subset analysis here would suggest that there wasn't actually a significant improvement with a compression injury, not a compression, not a chronic compression with, with the, with the supercharged transfer. So just in summary, we really want to pay attention to the goals of what we're trying to accomplish with this patient.
FRASER LEVERSEDGE: We want to improve sensibility, maximize motor nerve recovery, improve our intrinsic function, avoid progressive nerve dysfunction or worsening of the condition, and to minimize risk. And for those I would defer to the good Canadians here. If you don't like anything that our panelists say in their debate, you want to do a good job the first time around here. So our three teams. Travis Blood, is a fellow from Brigham.
FRASER LEVERSEDGE: He'll be discussing insights on nerve decompression. Brian Freniere from the Mass General will be discussing anterior transposition and we have the final member of our team here, Tyler Evans, who will be discussing from The Ohio State, anterior transposition with distal end to ulnar motor transfer. So with that, I will ask Travis to go ahead and you can take over the screen there to start us off.
TRAVIS BLOOD: OK thank you. Let me share my. Can everybody see that? Yep. OK. So thank you, Dr. Leversedge. I hope everyone is staying healthy and hopefully we're all slowly moving back to the operating room.
TRAVIS BLOOD: I am Travis Blood. I'm one of the Brigham and Women's Fellows, as Dr. Leversedge mentioned. I want to thank Dr. Blazar for being my mentor and I think together we're going to be able to convince you that in-situ decompression for chronic cubital tunnel syndrome is the right operation in many patients presenting like the case shown. So here's the case Dr. Leversidge already went through, so I'll skip through.
TRAVIS BLOOD: This type of compression can be classified as either a Dellon severe type compression or a grade three McGowan indicating persistent sensory symptoms with persistent atrophy and weakness as well as intrinsic dysfunction. So oftentimes in hand surgery, we have the procedure that is tried and true. However, in some cases we don't always have that one procedure that works each and every time.
TRAVIS BLOOD: This case is a perfect example of a case where it's not necessarily one correct answer, but I'm going to try to convince you that in-situ decompression is the right choice in this patient. So knowing that surgery is indicated in this patient, there are few options that come to mind. So the surgical options consist of in-situ decompression, anterior transposition and transposition with supercharged or N2 ulnar nerve transfer.
TRAVIS BLOOD: But in my mind, inside decompression is the treatment of choice. I've been trained by my mentors here in Boston that when deciding on a procedure, we first look at the level of evidence and what supports the procedure of choice. And there are multiple level one studies that support in-situ decompression as the treatment option here.
TRAVIS BLOOD: So I'm going to start this prospective randomized controlled trial done by Gervasio and the Journal of Neurosurgery in 2005 looked at 30 patients, randomized sorry, 35 patients randomized to each group looking at simple decompression versus anterior submuscular decompression. They found that there was no significant difference between the outcomes in the two groups. Looking at the Bisher score at six months and four and up to four years.
TRAVIS BLOOD: They also found that 80% of patients rated their outcome as excellent or good, and they had full return of sensation as well as motor in up to 33% of their patients. And another prospective randomized trial done by Biggs and Curtis, they looked at 44 patients, 23 in the decompression group and 21 in the submuscular transposition. Both procedures showed comparable clinical improvement, with 61% in the decompression group and 67 in the transposition group.
TRAVIS BLOOD: A subgroup analysis looking at the medium and high grade McAllan scores showed 82% improvement in the neurolysis group and 68% improvement in the submuscular group, indicating that patients were getting better with the submuscular sorry, getting better with the neurolysis over the submuscular transposition. Interestingly, they also found that there was no complications in the decompression group, but 14% in the transposition group.
TRAVIS BLOOD: Not to beat, not to beat a dead horse but another level one study by Bartels et Al showed similar results at one year, with 50% of patients getting complete resolution of symptoms and 80% having improvement. But this study also looked at the complications, and you can see that looking at a total of 152 patients, they randomized into two groups and they found that the complication was greater in the transposition group with a 31% complication rate versus 10% complication rate in the decompression group.
TRAVIS BLOOD: Similarly, looking at specifically at the complications of the two procedures, a recent retrospective study done at Brigham and Women's that was published in the Journal of Hand Surgery showed no difference in complications between the two groups, but a secondary surgery rate of 11.1% versus 2.5% for decompression. So this here just shows us that there's significant more complications in the transposition group.
TRAVIS BLOOD: Speaking of revision rates, the paper by Calfee is commonly cited by sceptics as a reason for anterior transposition over in-situ decompression. However, Calfee et al found that the predictors of revision were McGowan stage one, which is limited disease. Often these patients can be treated without surgery or patients following elbow fracture or elbow fracture dislocations, which is a totally different subset of patients that we have here.
TRAVIS BLOOD: To counter the Calfee et Al paper, there was a multicenter trial done by Song et al, showed a revision rate of 2.5% And there was also a study done out of Philadelphia by Osterman et al that showed a revision rate of 3.2% This labeled the operation of simple, of a decompression as a simple procedure with minimal risk.
TRAVIS BLOOD: So lastly, this brings the question of supercharging the motor branch of the ulnar nerve with the AIN. In other words, plugging a garden hose into a fire hose to improve intrinsic function. Sorry I think I skipped this. As of now, we'll let the colorful pyramids explain where we are with that reporting level four and five evidence.
TRAVIS BLOOD: It's too early to say it won't work, but there is still more evidence that is needed to prove that this is a good operation. Until now, I'll have to go with the author's comments that says post-operative improvement in intrinsic function in the study could be done to related to a number of factors other than the supercharged end to side motor nerve transfer, such as concomitant ulnar nerve decompression at the elbow or the wrist, and not sure if our colleagues will be arguing for the supercharge
TRAVIS BLOOD: agree with this statement, but will we'll see what they have to say. So this supercharged kind of reminds us of this little script. Hold on. There we go. So if you had to make a choice between a small surgery with the same outcome, lower complications, that is supported by level one evidence, what would you do?
TRAVIS BLOOD: And so, Dr. Blazar. It looks like we win again. Do I have? Thank you.
FRASER LEVERSEDGE: Great thanks, Travis. That was very nice. So I'm not sure what you're going to do without a quarterback next year.
FRASER LEVERSEDGE: So hopefully that, that, that brings up the level of evidence. So our next presenter from just not too far away down the street. Brian, are you there for? Yes, I'm here. Anterior transposition. Great get my screen up. He drew the first blood, but it won't be the last.
FRASER LEVERSEDGE: Biggest words from the guy with the chess pieces in the background. But it's a real chess metaphor, Phil, because there's only one King standing, if you look carefully at the screen. And that's why you're sitting down, Kyle? Well played.
FRASER LEVERSEDGE: Well played.
BRIAN FRENIERE: Can everyone hear me and see my screen? Yes great. So thank you, Travis, for that wonderful presentation. We're now here with the rebuttal as to why anterior transposition should be the choice of procedure for our patient. I'll briefly review the indications for this procedure, in particular some of the general techniques, some pearls and pitfalls for this procedure in particular.
BRIAN FRENIERE: A little bit about the outcomes and we've already heard a little bit about them. But then in this case, specifically, why anterior transposition? And I think Travis proved exactly what I thought he was going to, putting a lot of evidence out at us. But in our heart of hearts, is this really the right procedure and this is this what you would want for your family based on level one evidence alone?
BRIAN FRENIERE: So what are some consensus and consensus in a loose terms indications for a transposition? I think the majority of surgeons would note that it should be the procedure of choice for those with pre-op subluxation, subluxation appreciated during intra operatively during in-situ or planned in-situ decompression for a revision of a failed in-situ decompression.
BRIAN FRENIERE: Those who have had a prior significant elbow trauma as well as sharp transection and ulnar nerve at the level of the elbow or lengthening is required. What are the technical options? Briefly, there's the traditional pure subcutaneous and it's been modified. The Rosenwasser, it's described the adipofascial sling. There's also the subfascial or intramuscular technique.
BRIAN FRENIERE: And then the originally described pure submuscular technique. Some pearls and pitfalls. I think we've heard about some of these already, but taking care of for adequate mobilization along the length of the ulnar nerve as it crosses the elbow, avoiding the kinking that we saw earlier, but also taking care in diabetics or other high risk populations to ensure adequate blood supply to the nerve. Of course, not to overtighten in the tunnel that's created with either the facial or adipofascial sling or in the intramuscular tunnel, ensuring that the nerve glides with range in the elbow, ensuring that the branches are adequately mobilized so they don't tether, become tether sites for the nerve and then meticulous hemostasis
BRIAN FRENIERE: so a hematoma doesn't undo the good work. Now what can we say about this procedure? Well, I think despite what we've heard earlier, relatively low complication rates in the single digits and large studies with over 1000 patients, in the majority of these complication rates that I think we've heard about are focused around scar sensitivity. And there's evidence out there from Dr. Calfee's group as well, that at about two months, a lot of these, a lot of the morbidity is similar in situ as well as transposition.
BRIAN FRENIERE: And then I think also we've seen in large series that are contemporary and I think change from past low revision rates in the single digits as well with several years of follow up. But most specifically for our patient here, what do we see in terms of recovery in those patients with McGowan 3 ulnar neuropathy with decompression transposition alone? And I think if you look at some of the experts who are littered across these papers that I've outlined here and those patients who are followed for an extensive period of time, transposition has yielded very predictable results with low complication rates numbering in the low single digits with excellent results.
BRIAN FRENIERE: And we've seen that even in those patients with severe ulnar neuropathy, there's good recovery in terms of both sensory and motor function within the hand and I think that's something that we must consider when looking at the expert opinion out there that those pillars of the field of nerve surgery really have a predilection to transposition. So I think in terms of looking at the critiques we're going to get from both ends, I think we've already heard from the minimalists that the outcomes are the same and that we can always transpose later if we need a revision.
BRIAN FRENIERE: And I think looking towards the SETS camp that I think what they'll claim is that the advanced changes at the elbow are just too far to recover and that there's little downside to supercharging. So looking at each of those, I would propose that the best solution probably lies somewhere in the middle so the outcomes are the same.
BRIAN FRENIERE: I think Travis has outlined all four of these studies brilliantly and gone through them very detailed, but what are we look, if we pull that data and we look at studies that have only with some more prospectively prospective studies and what have they shown in a pooled meta analysis? Well, if we look at that, in 10 studies that have 449 compressions, 342 subcutaneous, 115 submuscular,
BRIAN FRENIERE: while there wasn't a statistically significant difference, there was definitely a trend towards improved clinical outcomes with transposition as opposed to simple decompression. And I think this forest plot demonstrates that nicely that while the evidence might not be there, probably due to the low numbers, there's definitely a trend towards transposition being superior in terms of clinical outcomes when we look at a larger series.
BRIAN FRENIERE: And I know Travis has already highlighted this already, but that at a minimum five year follow up and if we follow these patients for a long time, the outcomes for insight to have a higher revision rate and studies that are out there in the literature, this one coming from Dr. Hutchinson. And I would harken back to the long term follow up that I think is required for a lot of these patients.
BRIAN FRENIERE: Many of the in situ studies have a short term follow up but if we follow our patients out over a long period of time, they have good outcomes and there are few reoperations as this study coming from Dr. Jupiter. If the argument is that you can always transpose later, I think that the outcomes are not as good and we've seen that in multiple studies, not only the one from Dr. Calfee, but also this one in a neurosurgical journal looking that of those patients who underwent transposition for revision, less than half had improvement in their pain sensory motor function.
BRIAN FRENIERE: So don't think that it's always true that you can easily transpose later and have good outcomes. Well, looking to the SETS folks, maybe that it's just advance changes will not recover the procedure only at the elbow. And I think we've see in these long term follow up studies from those pillars in the field that that's not true
BRIAN FRENIERE: and we do have improvement in our patients with severe changes with just decompression and transposition alone at the elbow. And I think we've already seen this article highlighted by Dr. Leversedge, but we just don't know what to say about that and whether it's
BRIAN FRENIERE: the transposition at the elbow, that's really the driving factor in the studies that have looked at SETS,
BRIAN FRENIERE: we don't know, and I would advocate that until we do know, it may not be worthwhile. As always, there's little downside to supercharging, but they're in surgery. There's no such thing as a free lunch and complication rates, cost and whatnot must be higher for a procedure that takes longer and is more invasive. So while there's a nice new shiny car Ferrari out there, I think that the tried and true method that we've developed with anterior transposition always trumps that and ends up on top.
BRIAN FRENIERE: So I appreciate your time and I hope you'll consider our argument in favor of interior transposition as the favored approach for chronic ulnar neuropathy with severe changes in the hand.
FRASER LEVERSEDGE: Great thank you, Brian. I think that was Tom Brady's truck trying to leave Boston really quickly. Foxborough. So our last, our last, our last
FRASER LEVERSEDGE: speaker. Tyler, are you there? You can take over the screen.
TYLER EVANS: Absolutely give me one second here. Can everyone hear me? Yes, yes. OK, good. All right.
TYLER EVANS: Thank you for allowing me to present today and thank you to Dr. Moore for her expertise on this topic. I'm going to present to you the top five reasons to do an ulnar nerve transition and an AIN supercharge. So we heard the arguments from the other two options for this patient with chronic ulnar nerve compression with intrinsic atrophy. But I don't believe that those options are enough for this specific case.
TYLER EVANS: He has, he's an avid guitarist requiring strong intrinsic to do something he loves. He has atrophy and weakness already and with EMG findings of an axonal injury. Luckily there is another option, and that's the supercharge. In the last decade AIN supercharged nerve transfer has gained a lot of attention for a treatment of this specific issue. There's a lot of naysayers still, but I'll give you five reasons why I think that this is a good treatment option for this specific pathology.
TYLER EVANS: So what is a supercharged nerve transfer? Supercharging refers to a transfer of an expendable distal motor nerve to the side of an injured recipient nerve. The donor distal end is co-apted through a perineurial window to enhance regeneration of that injured nerve. As you can see, the traditional end to end or end to side transfer requires transection of that recipient nerve which takes away any chance of proximal regeneration from the injured nerve itself.
TYLER EVANS: But the supercharged underside allows for both proximal regeneration and the additional regeneration from the donor. So why supercharge the ulnar nerve in this case? Well, I think the answer is pretty clear. Do you want the Ford Pinto with custom wood paneling or do you want the 1967 supercharged Ford Mustang, Shelby GT 500 with 770 horsepower? Who doesn't want that additional power?
TYLER EVANS: So when do you do a supercharger AIN transfer and cubital tunnel syndrome? Well, I think you have to have physical exam findings, obviously, of compression and intrinsic weakness, mostly a diagnosis from physical exam but then you look at also the nerve conduction studies. They must have evidence of muscle denervation, which can be seen with positive fibrillations and also reduce CMAPs.
TYLER EVANS: And then number three, the AIN must be a viable donor, which you can see on EMG, for example, in a CATD1 radiculopathy, the AIN may not be useful. So the first reason, we all know the old phrase, time is money but in terms of nerve injury, time is muscle. So the more distance to travel, the more time. The more time it takes, the more muscle loss, the more muscle loss, the less function.
TYLER EVANS: Functional recovery is related to maximizing the number of motor axons and minimizing the time to rennervate the motor endplates in muscle and too much time passes. There's an irreversible loss of those motor endplates through degeneration and fibrosis and nerve damage. Schwann cell support diminishes, leading to apoptosis and loss of trophic support. Both of these greatly impact the functional recovery.
TYLER EVANS: So we all know that the nerve regenerates at a rate of about one millimeter per day, one inch per month, one foot per year. Irreversible muscle atrophy has been shown to occur anywhere from about a year to 18 months. So proximal insults to nerve greater than a foot away from the endplates are at risk. The terminal AIN branch has about 600 axons and is very distal. If we are able to add those motor axons and shorten the distance to the motor end plates and we can shorten the time to regenerate those distal intrinsic muscles.
TYLER EVANS: You can clearly see in the bottom picture that the terminal axonal sprouting and reinnervation by the increased fluorescent staining in an injured recipient nerve. So reason number two, it's an easy dissection and it's a very consistent anatomy. So you can see here, this is the anterior interosseous nerve transfer first described in 1997. You can see the terminal AIN branch here going to the pronator quadratus and the approximate harvest site of the ulnar motor portion.
TYLER EVANS: This is a great anatomical picture here that shows the ease of dissection under the flexors to expose the PCU and the AIN with the ulnar nerve nearby, feathering through the PCU with a bipolar until the AIN starts branching, you can get an adequate length for a tension free repair, which is important. The recipient ulnar motor component is shown here. This can be etched in your memory pretty easily to know where the motor component is.
TYLER EVANS: If you just remember sensory motor sensory, meaning you have the dorsal sensory branch coming off the ulnar nerve most ulnarly, then the motor component, then the rest of the sensory component of the ulnar nerve. It's easy to remember: sensory, motor, sensory. This is just a depiction of the AIN transfer to the ulnar motor portion with no tension, usually done about 9 centimeters proximal to the wrist crease. It's very important here to follow good microsurgical technique and especially not putting sutures through the axons themselves.
TYLER EVANS: You do create a perineurial window, but sutures should only be placed through the epineurium. Poor technique, suture knots within the axons and too much tension will lead to poor outcomes. Reason number three is you have improved functional and DASH outcomes according to some studies. This study here, basic science, showing that when looking at muscle force after super charge transfer, when you transect the donor nerve, the specific force actually decreases.
TYLER EVANS: So you will likely have some proximal regeneration from the release and transposition itself only. But this gives support that the super charge can help give you additional renervation and muscle recovery. So this study by Dr. Moore and Dr. MacKinnon with 55 patients showed overwhelming majority of patients improved their MRC category, had significant improvement in their DASH scores and increased their strength of an averag of about 3 pounds of force.
TYLER EVANS: This study showed that about 84% of supercharged transfers showed intrinsic recovery, compared to about 38% in the non-supercharged group. And this study in 2019, a systematic review recently published reports that grip and key pinch strength improved 202% and 179% respectively, and that 92% of patients recovered intrinsic function after supercharged AIN transfers.
TYLER EVANS: And in this study, recently published January 2020 by Dr. Moore, Dr. McKenna shows that you need about 70 to 80% of motor neuron loss before you have functional loss. So really what we need then is to get about 20 to 30% reinnervation for any functional recovery. So reason number four, there's minimal donor morbidity, really. We believe that you should release Guyon's canal. On this case as well,
TYLER EVANS: due to the double crush phenomenon that was described in 1970s by Dr. Upton, the nerve becomes especially susceptible to compression at another site when it's compressed elsewhere. So this incision is just an extension of your Guyon's canal release. There's minimal traumatic dissection as you stay mainly within the loose areolar plain under the FTP and you just feather through the pronator quadratus until the AIN begins to branch.
TYLER EVANS: Pretty simple. And when we talk about the denervation of the pronator quadratus, I mean, who really cares, right? How many of you guys actually do a meaningful repair after a blasted distal radius of the pronator quadratus? I don't think many people do. And this study shows that comparing repairing the PCU really has no difference in DASH scores, range of motion or pronation, post-operative pain or complications at the 12 month mark after distal radius fractures.
TYLER EVANS: And other studies have also shown denervation of the pronator quadratus has no effect on postoperative pronation. And then the last reason; I wouldn't be a plastic surgeon if I didn't have to mention Cosmesis. And so do your patients really want atrophied, weak and aging hands, or do they want young, strong, youthful hands? Even Michelangelo knew the importance of strong youthful function,
TYLER EVANS: functional hands. You can see a very strong first dorsal interosseous in both his painting, the Sistine chapel and also in the statue of David. So again, here are the top five reasons I think you should consider supercharging with AIN. Time is muscle. It's an easy dissection and consistent anatomy.
TYLER EVANS: You get improved functional and DASH outcomes, minimal donor site morbidity and improved Cosmesis. In conclusion, the case presented showed a patient with chronic ulnar nerve compression with weakness and atrophy, and somebody who uses his intrinsic muscles very often in a, you know, avid guitarist. He has EMG with positive fibrillations. Our recommendations are that this patient would most benefit from complete decompression and an AIN end to side supercharge transfer to the ulnar component.
TYLER EVANS: Thank you.
FRASER LEVERSEDGE: Great thank you, Tyler. I'm going to take over the screen here for. Well, those were fantastic presentations and I think as our next step here, we do want to hear a little bit from the faculty as we've had three methods of treatment.
FRASER LEVERSEDGE: But as we know, not everyone's the same and I'm curious with, with our index case here, we'll have a couple of topics to discuss. And I wonder from Doctors Moore, Dr. Eberlin and Dr. Blazar, as you've presented your cases and your and your rationale for treatment, are there, are there things that you consider in your preoperative assessment and I would include age in this as to how you might take care of this patient with intrinsic atrophy in a compression neuropathy, not in ulnar nerve, higher ulnar nerve injury, but a compression, neuropathy, anything in the preoperative assessment that you use to make a decision either for your treatment of choice that you presented or any of the other treatments.
FRASER LEVERSEDGE: For example, preoperative assessment of with ultrasound or specific testing that you might consider, such as with the EMG. Phil, any, any comments?
PHILIP BLAZAR: Uh, sure. Uh, first of all, I think all three Fellows did a nice job, so I want to compliment them on that. Um, you know, one of the most important things for me, and I'm just going to pick one to answer your, your multi-part question Frazer, is really trying to get a sense of the timing.
PHILIP BLAZAR: So I think the two things that have really predicted in my anecdotal experience, recovery of intrinsic function or length of compression, which can be very hard to estimate, but sometimes with a careful history, you can get a sense of it. And then age of the patient is, as you said, you know, nerve things, nerve pathology in general. Recovery really is very dependent on the age of the patient.
PHILIP BLAZAR: And, you know, it almost goes by, by 20s. You know, if you're, if you're under age 20, almost any nerve pathology with a reasonable solution will have a good result. 20 to 40 is still pretty good. 40 to 60 is favorable, but not great. You get to be over 60, and our neuroplasticity and our biologic capability of regeneration in my hands starts to diminish.
PHILIP BLAZAR: And you get to be over 80,
PHILIP BLAZAR: and you know, for most people you're talking about pain relief with most nerve surgeries. So, so two things that I try to assess, age is easy to assess, chronicity is hard to assess right? So Tyler mentioned.
KYLE EBERLIN: Oh yeah, comment about that. I agree with everything Phil said. I think ultrasound is really helpful in the office for this particular type of patient because you can see in real time if there is subluxation or perching, and I have found that if it if that is happening and you're going to talk to the patient about transposition, it makes that discussion a lot easier
KYLE EBERLIN: if if they're looking at the image with you and they're seeing their nerve move into the medial epicondyle, you can explain the logic behind transposition and why it might be something that's effective. So I think in addition to the time course which Phil mentioned, knowing what is going on with the nerve, is it just compressed like with an anconeus or is it really mobile or or is is the is the movement of the nerve something that's causing this this ulnar neuropathy?
KYLE EBERLIN: So I think that is critically important for cubital tunnel syndrome.
FRASER LEVERSEDGE: I would I'm going to jump in. I would agree with Kyle. I'm interested in what other people think in particular and we'll start with you, Kyle. Most patients that I see, I don't have too much trouble on physical exam assessing for subluxation of the ulnar nerve. I agree that there are studies out there that say we may not be so accurate, but my impressions, I think, are backed up in the operating room and actually physically looking at the nerve.
FRASER LEVERSEDGE: So I think it's the minority of patients that I have trouble assessing that. And I'm interested in what other people think about the ability to assess for subluxation in the office.
TYLER EVANS: I'm going to jump in then I want to ask Amy because I think Amy's opinion will be very valuable here. But I think when the nerve is is clearly subluxing, anyone can tell.
TYLER EVANS: I could take a first year medical student and they could figure that out. I think the challenge is when the nerve is just perching a bit and we all get in the operating room and you're planning to do an in-situ and you're moving the elbow and you're like, gosh, I don't know if I should transpose it or not, even if you're planning to do an in-situ. So I think the cases where there's some gray area where it's not obvious, that is when it's it's even more helpful to really visualize it.
FRASER LEVERSEDGE: OK Amy. Amy, do you want to weigh in for a second there?
AMY MOORE: Yeah I mean, I don't want to disagree with anybody. I don't think age of the patient matters at all. When I treat patients with nerve injuries, I take it into account of understanding it's going to take longer. I mean, there's been every rodent study to show that nerves of older rodents regenerate slower
AMY MOORE: and I think that's in humans too. But I don't change the procedure I'd offer for somebody based on age. The other thing that I use preoperatively that's important to me is the electrical studies and not so much time. It's because of that graph that we showed when we were discussing our nuances about this is that patients will have horrible atrophy and they'll say like, oh, I just started feeling weak a month ago.
AMY MOORE: So I don't trust patients to understand how bad is that compression to lead to loss of fibers that's going to finally make them fall off from having a functional outcome. And if we can just do something to get them back on the cliff where they have function. So Tessa Gordon did this study out of Edmonton at the time and showed that you can lose 70% of your motor neurons and still have normal function, but you lose 72% and you drop off completely.
AMY MOORE: And so I think understanding time point is maybe a less of an importance is to determine, OK, well, what can I do about it? And so then that becomes as surgeons, what can we do and the EMG will show fibrillations, which will show that the muscle is alive or not. And if there's no fibrillations and you have atrophy, you're not going to supercharge because it's already too late and so that's how I develop my chronicity.
AMY MOORE: Whether I use ultrasound, I don't have access to that so I don't, I think that that's an intraoperative decision that I make. But if I had it as a tool, potentially, but I do think the preoperative assessment of these patients to know what you're planning to do matters.
FRASER LEVERSEDGE: Warren, you're going to, you're going to say something earlier.
WARREN: Was just going to ask for Kyle or anybody that does ultrasound, does the cross-sectional diameter or cross-sectional area of the nerve come into play in your decision when you're going to decide?
WARREN: Or is it just you're using the ultrasound to see if it subluxes?
KYLE EBERLIN: Um, you know, I know that's been described and certainly John Fowler has done a lot of great work on that. I look at it, but to be honest, it's not something that I use to decide about my technique. So you're doing a dynamic study looking for hypermobility or subluxation of the nerve? Primarily primarily.
KYLE EBERLIN: And, you know, frankly, as I said earlier, I think it really gets the patient on your side and they get to see what's going on. I show them on the imaging, so I think it becomes a more interactive consultation and some of these patients who, you know, like the patient Amy mentioned, who comes in like this one right here comes in. So it's been going on for two weeks.
KYLE EBERLIN: And you look at their hand, you know that's not possible. It helps you to kind of educate them and it just gets them on your side a bit more.
FRASER LEVERSEDGE: Right so distal ulnar tunnel decompression that Tyler mentioned. Kyle anterior transposition. Any role in your sort of perspective of of somebody with intrinsic atrophy, any role for distal ulnar tunnel decompression without known pathology at the wrist, i.e. ganglion cyst, et cetera.
KYLE EBERLIN: I think if the EMG shows something there, obviously you should target it and that's a good indication to do it. If the EMG does not show you something, I think it's kind of dealer's choice and I will say parenthetically, I perhaps become a bit more aggressive about thinking about it if the patient is young and starting to get some intrinsic atrophy.
KYLE EBERLIN: But I do not know the answer about when objectively it's required or it's very difficult to even prove if you were to do it, whether it's made a difference.
FRASER LEVERSEDGE: How about if you do a set transfer? Is that decompression is routine for you also?
KYLE EBERLIN: Yes, that's that's part of the procedure. And I believe that you need to release all of the the compressive forces of the ulnar nerve as it sort of wraps around the hamate.
FRASER LEVERSEDGE: And Phil? So starting with the last one, when
PHILIP BLAZAR: I do a sets, which I almost only do for a laceration of the nerve, I will also decompress the ulnar nerve distally. But but I think the two pathologies are different. You know, I think a a lacerated or otherwise completely disrupted nerve, I think the pathology is very different from a nerve compression.
PHILIP BLAZAR: But but. You know, it's also interesting, at least with the neurologists and PM&R docs who do the EMG excuse me, do the electrodiagnostic testing in my practice, I have to specifically ask them about the distal ulnar nerve. I don't think most of them will do studies that are specific enough to to pick up if there's two sites of compression there.
PHILIP BLAZAR: So, so I find that only helpful if I ask and and so, you know, and I will if I'm the one ordering the test, I frequently if they seem to have distinctly more intrinsic dysfunction than other dysfunction, I will specifically ask them to look at that. And I've been surprised that a moderate percentage of the time they will find something and I will decompress it. So the you know, the answer is I don't know what the answer is because I don't think we ask the questions often enough.
PHILIP BLAZAR: And so anyway, those are my thoughts about the about the ulnar tunnel.
FRASER LEVERSEDGE: Amy, just Phil brought up a point there, and I mentioned it earlier with Steve Moran's paper and follow up. Do you see much of a difference between an ulnar nerve, high ulnar nerve injury compression type injury versus a chronic compression neuropathy at the elbow, any different from how you manage the nerve distally?
AMY MOORE: I don't do anything different, truthfully, whether it's a transection or a severe compression, they get a super charge. I know there's arguments that I should go into end, but because of my science, I'm biased to not and I've really been happy with the results by doing a super charge looking at my patients. Um, so I also, though, really, truly believe in the double crush syndrome, right?
AMY MOORE: And think that if someone has severe compression proximally, they're more inherent to compression distally. This has been thought and discovered a long time ago, 1970s right? So if I have somebody and I treat the patient and what the patient needs is more, then I'm going to give them the one surgery that's going to cover it all. And so, yeah, maybe aggressive, maybe not.
FRASER LEVERSEDGE: How about the high ulnar nerve injury with a patient with a Martin Gruber interconnection? Is that patient get a transfer distally?
AMY MOORE: They do. They do. Because they even those with the Martin Gruber where you're just like, oh, and it really throws you. I don't I don't think that PQ matters and I think those ulnar intrinsics you're just creating like a third, um, like, I mean, this is a sort of a weird way to say it, but think cassettes creates a Martin Gruber, right?
AMY MOORE: So you get two sources of axons and motor neurons at the spinal cord level filtering in to to do the motor endplate reinnervation and we know after any injury that there's never a complete 100% reinnervation of all the motor end plates. That's why we have fibrillations that last much longer than recovery. And so the idea is to get as many sources of axons to those muscles to give it the best potential.
PHILIP BLAZAR: No, I'll agree with Amy on that and I don't have her experience of doing an excuse me distal AIN to ulnar nerve motor transfers, but I happen to have done a couple of my early ones in people with that Martin Gruber and those those folks do better than anybody else because they do have the multiple sources. And so, you know, that person with the known high ulnar nerve injury who, you know, can do can do a demonstrate a little bit of intrinsic function in the ER, you know, in my, in my hands.
PHILIP BLAZAR: You want to do that there because because they're going to get to that 70% motor neuron function much more easily than other things.
FRASER LEVERSEDGE: Right so so, Phil, while you're while you've got the microphone, anything you mentioned inside your decompression, but no one mentioned endoscopic in-situ decompression. I've found that there's been some concerns about appropriate use of endoscopic methods.
FRASER LEVERSEDGE: You may miss the sort of the aponeurosis and the deep portion of the FCU and even more distally where you can still have tethering of the ulnar nerve between the heads of the FCU. Any thoughts about endoscopic for this patient, or would this be a mini open or a reasonable incision for somebody with intrinsic atrophy that you don't want to leave anything behind?
PHILIP BLAZAR: The only experience I have with endoscopic is in a cadaver so everybody should take what I say with a grain of salt, you know? How did the patient do? No complaints. You know, so my complication rate is zero. So no. So there is a you know, as everybody knows, there's a moderate body of literature on endoscopic decompression and
PHILIP BLAZAR: but not a lot of, you know, level one studies comparing not any level one studies that I'm aware of comparing to the more standard, although they may be out there. And I do think, like with any endoscopic technique, there is a concern for what can't you see? And so I obviously haven't gone to doing endoscopic techniques because I said the only one I've done is in a cadaver.
PHILIP BLAZAR: So, you know, maybe others have more experience and can comment on it. But I guess I would say I share your concern. I also think that you can do, you know, a endoscopic release and go 8 centimeters above the epicondyle and 8 centimetres below the epicondyle through a pretty small incision. So it may be a little bit of the triumph of technology over reason, but I'm interested in others comments.
FRASER LEVERSEDGE: Kyle or Amy any, any experience with endoscopic.
KYLE EBERLIN: I don't have any experience with endoscopic other than a cadaver also, so I'm not the best person to comment, but I am either technically inadequate to do it or I'm petrified of cutting the nerve or an MACB branch. And I just, I mean, I think the first time that ever were to happen, it would just be so catastrophic that I just am not willing to consider it. And I have taken care of a few patients who've had ulnar nerve injuries from endoscopic release.
KYLE EBERLIN: So that that shaped my perspective.
AMY MOORE: Yeah, that's, that's the only ones I've seen are the ones that I've fixed from somebody else's damage. So I'm just biased. Like I haven't been able to celebrate other people's success with that. And that's the same thing at the risk. Um, you know, my, my partners at Ohio State do a lot of the endoscopic carpal tunnels and I'm just like, well, I'll never do it, but I'm glad that they do it so well.
AMY MOORE: And so, you know, it's great, but I just haven't been so biased to treating people's unfortunate, um, complications.
FRASER LEVERSEDGE: Great and and Phil, just since you were the in-situ person, do you, do you supplement the concerning nerve that's starting to perch a little bit with any form of trying to deepen the, the, the cubital tunnel with a partial medial epicondylectomy or anything along those lines that have been described.
PHILIP BLAZAR: I do not. So if I have concerns about nerve instability and, you know, I certainly have a handful, no pun intended, of people who of mine who have gone back for subluxation that either didn't pick up on interop or it developed post op, but but I transposed the nerve, you know. So if I have a real concern about instability, I transpose the nerve. I have done medial epicondylectomy some in the past.
PHILIP BLAZAR: So it's not that I have zero experience, but but it's not part of my armamentarium at the moment except for perhaps in some unusual situation.
FRASER LEVERSEDGE: Right so anterior transposition. Kyle, you spoke to anterior transposition. Any preferred method?
KYLE EBERLIN: Yeah, I think you were just about. That wasn't. That wasn't supposed to show you or lead you on in any way?
KYLE EBERLIN: No, I really like the adipofascial flap that was described by Mel Rosenwasser. from JHS and there are a few reasons that I like it. You know, nerves like to be around fat, nerves like to be around vascularized tissue and that fulfills both of those roles. But perhaps most importantly for me, it really provides a long runway for the nerves. So that I think in my practice it's a bit less likely to get the zigzag deformity because it's providing basically a shoe for the nerve as it runs throughout the entire length across the antecubital fossa.
KYLE EBERLIN: So as you can see in the picture, which is quite well shown, I think it's a nice flap. It's very, very easy to do. You do have to be careful of the MACP which runs kind of in it. And but other than that, it's, it's my preferred technique for transposition.
FRASER LEVERSEDGE: So, Amy, with this patient, with, with chronic compression, neuropathy and intrinsic atrophy, what is your go to in terms of transposition portion of the case?
AMY MOORE: Yeah, I do that subfascial. I don't do the whole intramuscular thing that I learned from Susan McKinnon, but I definitely use the fascia and try to get it into a straight line. I'm most concerned of the distal kinking at the FCU and that there's the fascia that comes through there. So I basically release all fascia tethered for about 3 centimeters along the bone along the ulnar.
AMY MOORE: And so I don't allow there to be any distal compression. And then I put the arm through full range of motion to make it. But I'm most worried at that distal than I am proximally so I spend a lot of time fussing there.
PHILIP BLAZAR: Yeah, I agree with that. And I often will dissect out that first branch of the FCU, which you can see here, even back into the ulnar nerve a bit, just to allow that the nerve to lie a bit straighter.
PHILIP BLAZAR: I think that can be a very helpful trick. Totally agree.
FRASER LEVERSEDGE: And it looks this is this is a video of my patient, but it looks like the nerve is brought really anterior here. But this is just the adipose fascial flap being retracted anteriorly. But the point of the video is really to show the distal decompression here and to Amy's point, I think that's that's a really critical aspect of our procedure.
FRASER LEVERSEDGE: And it's oftentimes a worrisome area because we we sort of don't want to spend the time to to dissect out the motor branch and to really free up the nerve. And ultimately, we, we probably add to the potential for more distal nerve tethering. Phil, Phil, any any preferences for transposition of choice if you were to, because obviously you're insights you may not have worked or you had to go back or if you found a nerve that was unstable, what would your preference be?
PHILIP BLAZAR: Uh, depends on the patient. So one of the issues, Frazer, that you alluded to earlier is that one of the contributors to ulnar nerve pathology at the elbow is the superficial nature of the nerve, and so somebody without a significant subcutaneous layer of fat, I do not like to put the nerve under, you know, dermis with a few fat cells around it. I don't think that's healthy for the nerve.
PHILIP BLAZAR: So in that situation I will put the nerve submuscular and I tend to do it with a fascial lengthening. On the other hand, if someone has a, shall we say, more than their fair share or their fair share of subcutaneous fat, I will do a subcutaneous transposition. I completely agree with Amy about and you about the distal aspect being the area where I worry about the nerve not, you know, being kinked and having an abnormal plane.
PHILIP BLAZAR: And so I spend a lot of time on that distal FCU.
FRASER LEVERSEDGE: Right. And then Amy's, just any pearls for distal and ulnar motor transfer. If this was to be the case, and Tyler did a great job showing us the anatomy. You know, one of the questions is, do you need to dissect out the ulnar motor branch? You do an episiotomy. Any pearls of wisdom for securing your repair, for example?
AMY MOORE: Yeah, sure. I mean, I think as I've done this more and more, I have refined how I do this. But I think what's really important is to go enough proximally and release the muscle belly off the ulna so that you can dissect the AIN, not just distally into the muscle to get to where it's branching, but proximally so because there's all of the AIA, the artery that can kink it.
AMY MOORE: And so if you are addressing those vessels and pulling it over, you can have it lie under the ulnar nerve without any tension through full range of motion of the wrist. And so I'm not really trying to get it as distal. I just try to make sure I bring it over only to where it can hit the nerve. As for the nerve, I find the dorsal cutaneous branch that's my, that's my topography,
AMY MOORE: right? So as soon as I find ECU, I neuralize that proximally and I know the next segment is going to be motor. So early in my practice, yes, I did the skip dissections from starting distally, finding the motor branch and then following it, teasing it neurolysis with your eyes, whatever you whatever you want to describe it. But now I don't even bother doing that because the anatomy is all consistent.
AMY MOORE: Sensory, motor, sensory, that entire forearm. I had a patient with a stab wound up at the proximal forearm and we had to go in and look and it was still at that and be able to stimulate that, that topography was still solid proximally, so I'm pretty confident. The other pearl to make is the larger your epineurial window and then you spread over the perineurium the larger it is, the more fibers can sprout in.
AMY MOORE: And so that was shown beautifully in some transgenic animals where that the larger the epineurial window was, the more sprouting of axons in an inside manner. So I'm pretty aggressive on that. And then I just use the epineurium to suture loosely and direct, direct it like into it and I'm sewing the epineurium, but the fascicles are there spread to see the fascicles bulge but I don't injure the fascicles.
AMY MOORE: So I don't know if that, I don't know if that's very helpful or not, but that's what I do.
FRASER LEVERSEDGE: Kyle or Phil, any any comments about the distal nerve transfer? In just a minute or two we have left.
KYLE EBERLIN: Not really. I think Amy highlighted it and so did Travis exactly what
KYLE EBERLIN: I think about it.
FRASER LEVERSEDGE: Oh, this is just one Frazier one comment here. Sometimes we ask why our transfers don't work and this was actually a really interesting case that I came across. We actually explored what we presumed there was no real documentation for this patient. We did the procedure really for pain relief from the ulnar nerve at the elbow that had been unfortunately injured.
FRASER LEVERSEDGE: But she had no intrinsic function and we we explored what we presumed was a distal AIN to ulnar motor transfer as an end to end ultimately, and preoperatively she had no intrinsic motor function and prior to our neurolysis of the nerve transfer there was no response. And then we did a neurolysis and then intra operatively stimulated the nerve proximal to the transfer site and just found it was fascinating that there was now conduction.
FRASER LEVERSEDGE: So sometimes our nerve transfers don't always work for reasons that are beyond what we can actually see or look for, so it is it is something to consider as part of our technical ability and obviously for any of our, our procedures that we do, we always have to consider this as a reason why our procedures don't work. And then obviously distally, there's there's other reasons, there's other types of nerve transfers for the Fellows.
FRASER LEVERSEDGE: Hymie Bertelli's use of the branch to the opponent's transfer. If you think about your, your functional recovery for the ulnar nerve on the radial side looking for pinch and fine dexterity related tasks, the ulnar side more of the extrinsic function probably more helpful. So this may help to minimize the dilutional effect of a distal AIN to ulnar motor transfer and focus the recovery of the distal portion of the ulnar nerve.
FRASER LEVERSEDGE: You can see his work here. But I think we'll finish there. It's 7:00 our time here, 9:00 that time out on the east coast. And I think just to summarize, I think we all recognize this is a real clinical challenge. I think it's important to recognize that it really deserves a comprehensive assessment, whether you're looking for nerve subluxation or instability at the elbow, where you're looking for opportunities for nerve transfer, and being aware of whether or not you have an ulnar nerve injury or you've got a brachial plexus injury where your PQ may not be available or your AIN, I should say.
FRASER LEVERSEDGE: You want to honor attention to detail with your surgical technique
FRASER LEVERSEDGE: and I think that no matter what your decision for your preferred method of transposition, it's more about how you do it more likely in terms of your outcomes than than what you do sometimes. So again, optimize your nerve recovery potential is your goal and at the same time minimizing the inherent risks of your procedure. So I'd like to thank all of the faculty and the Fellows.
FRASER LEVERSEDGE: The Fellows did an outstanding job as they as they have been doing all along with this debate format. Thank you for your attention Warren and thanks for for your leadership and I don't know if you want to sign off for us here, but I'd like to thank everyone for your attention and thanks for participating.
WARREN: Yeah, I'd say thank you. Frazer you did a wonderful job as we anticipated.
WARREN: We had a good number of people tune in tonight or join us tonight and so I think that's outstanding. And the presentations were all excellent. I think we leave here probably still wondering what to do because they were all pretty convincing in their by themselves and then you listen to the next one and you say, well, maybe I should do something else.
WARREN: And the faculty mentors, the discussion was good. I think you also led your residents very well through this, so I commend everybody for the fine job tonight. We will rejoin Jerry and or I will send out the information for next week and we'll join again. Hope everybody stays safe and has a wonderful holiday weekend. Thanks, everyone. Have a good night.
WARREN: Bye bye. Cheers thanks, everyone. Thank you. Thank you. It's great to see you.
Segment:0 .
JEFFREY GREENBERG: Welcome to the next edition of the Hand Fellowship Virtual Debate series. This has been really a great series that Jerry started and Jerry has another webinar right now, so I'm going to do the intros and then turn it over to Fraser. So this is more of a traditional one like we started. Last week, we had a cocktail hour and then some faculty presentations.
JEFFREY GREENBERG: So we're going to go back to the fellow presentations and these have been, I think, a great experience for the fellows. They've done tremendous jobs with the presentations, given us really good presentations, and there's been great faculty input and participation in the discussion at the end and I truly anticipate this will continue tonight.
JEFFREY GREENBERG: So our team is going to start off with Dr. Leversedge as our moderator, formerly of Duke but now then he has moved to Colorado and seen the greener pasture, so he'll be able to ski and do some things he couldn't do well in North Carolina. And the debate is going to be between the team from Brigham and women's team from MGH and team from the Ohio State University.
JEFFREY GREENBERG: So with that, I will turn it over to Dr. Leversedge to start the program.
FRASER LEVERSEDGE: So there we go. Can everyone see that OK, Warren? Yep you're good. Perfect great. Well welcome, everybody, and thanks to everyone for participating and obviously to Warren and Jerry for this outstanding series.
FRASER LEVERSEDGE: This actually, this slide is from a top of Mount Baker, which overlooks Seattle. It was in Jerry's honor, overlooks my hometown of Victoria, Canada. And tonight, we're going to be looking at the management of chronic cubital tunnel syndrome with intrinsic atrophy and I think we all know this can be a challenging issue for restoring function and sensibility to the hand.
FRASER LEVERSEDGE: And I'd like to introduce our team. We'll introduce them individually as they get to their talks. We have, as Warren mentioned, a team from Brigham, Mass. General and The Ohio State, and we'll look forward to hearing from them. This is our format. We'll have a presentation from each of the Fellows for their respective charges.
FRASER LEVERSEDGE: Insight to nerve decompression, anterior transposition and anterior transposition with the addition of an anterior interosseous nerve to ulnar nerve transfer in the distal forearm. And then we'll have hopefully some time to discuss with within amongst the faculty in terms of the case and some some other challenges that come up along the way. So typically, the challenge for us is that there are several methods for many of the conditions we manage, and particularly the ulnar neuropathy at the elbow.
FRASER LEVERSEDGE: Each of these methods requires careful attention to detail, probably nothing more than the ulnar nerve at the elbow, both in terms of a preoperative nerve assessment and meticulous surgical technique to gain ultimately great outcomes. But we have to recognize that not all ulnar nerve pathology is the same, and this is where our challenges that we don't want to put things into buckets and treat all of the ulnar nerve conditions with one procedure
FRASER LEVERSEDGE: and I think that's going to be the important take home message at the end. There are many pitfalls that hopefully come out from our various discussions tonight when we have to recognize differential diagnoses and not so much part of this discussion, but I encourage the Fellows to really consider this. And then obviously with intrinsic atrophy, the influence of time really has to be considered for ultimately for nerve recovery.
FRASER LEVERSEDGE: And at the same time, the way that we manage the ulnar nerve, we have to remember that it's ultimately cranky and we have to be aware that it has a very low threshold for being insulted. This is our index case for this evening. This is a fairly straightforward, nothing hidden or surprise. 62-year-old right hand dominant accountant, an avid guitarist who's noted for years of progressive numbness to the small finger in particular with subjective weakness, medial elbow pain on clinical exam, a positive ulnar nerve flexion compression test and intrinsic atrophy
FRASER LEVERSEDGE: as you can see with the accompanying photograph. Radiographs of the elbow and wrist are without anything substantial in terms of abnormal pathology. And this is our nerve study that was obtained and sent to the clinic with the patient. You can see here the nerve study to the first dorsal interosseous abnormal. And then our EMG study demonstrates that the first dorsal interosseous two plus fibrillations, positive sharp waves and then reduced UAP's.
FRASER LEVERSEDGE: Just to add to our discussion, the pronator quadratus was all within normal limits. I think as we consider these three options, we have to consider the pluses and minuses and sometimes you can have a great day skiing on the downhill and sometimes once in a while you run into an avalanche and it's not so, not so pleasant. And so as we want to think about our our topics, recognize that there are some shortfalls of the insights, nerve decompression, as Ryan Calfee and others have shown us the potential for ulnar nerve hypermobility, you can see this in this patient undergoing a revision case for an in situ nerve decompression.
FRASER LEVERSEDGE: You look carefully here, you'll see the subtle instability coming now and you can see what happens and why the patient was symptomatic when that occurred. You can see the changes here at the wrist, which is demonstrating and not so happy ulnar nerve. There have been several studies that have looked at the potential re-operation rate and actually, Dr. Blazar, one of our faculty this evening, would suggest that it incites your nerve decompressions have a lower re-operation rate than anterior transposition.
FRASER LEVERSEDGE: Doug Hutchison, the University of Utah suggests that perhaps there's a higher re-operation rate in nerve decompressions not necessarily the same cohort of patients, obviously. Ulnar anterior transposition also has its relative difficulties. You can see here perhaps surgical technique misleading the ultimate outcome through a small incision and you can see here the ulnar nerve is lost,
FRASER LEVERSEDGE: it's anteriorly transposed position. But a careful look shows us that they've missed out on the principles of managing the ulnar nerve, leaving the intermuscular septum intact and perhaps not decompressing the nerve appropriately for its anteriorly transposed position. Submuscular transposition we think we used to think of as a panacea, not always gliding below the transposition site, below the flexor-pronator origin, and then the intramuscular and submuscular transposition which sometimes can be led astray with this serpentine ulnar nerve, which you can see here, is probably multiple points of tethering.
FRASER LEVERSEDGE: And not to be outdone, we know that there's been there's advocates on this panel for distal ulnar nerve or anterior interosseous nerve transfer to the ulnar motor nerve at the level of the wrist. And again, there's some good papers. I won't, I won't take Amy's thunder here with a really nice review article and their review of their clinical experience using the super supercharged endocyte transfer.
FRASER LEVERSEDGE: But we have to critically drill down on the data and this is a paper from Steve Moran and their group at the Mayo clinic and from Toronto, Canada, which in the subset analysis here would suggest that there wasn't actually a significant improvement with a compression injury, not a compression, not a chronic compression with, with the, with the supercharged transfer. So just in summary, we really want to pay attention to the goals of what we're trying to accomplish with this patient.
FRASER LEVERSEDGE: We want to improve sensibility, maximize motor nerve recovery, improve our intrinsic function, avoid progressive nerve dysfunction or worsening of the condition, and to minimize risk. And for those I would defer to the good Canadians here. If you don't like anything that our panelists say in their debate, you want to do a good job the first time around here. So our three teams. Travis Blood, is a fellow from Brigham.
FRASER LEVERSEDGE: He'll be discussing insights on nerve decompression. Brian Freniere from the Mass General will be discussing anterior transposition and we have the final member of our team here, Tyler Evans, who will be discussing from The Ohio State, anterior transposition with distal end to ulnar motor transfer. So with that, I will ask Travis to go ahead and you can take over the screen there to start us off.
TRAVIS BLOOD: OK thank you. Let me share my. Can everybody see that? Yep. OK. So thank you, Dr. Leversedge. I hope everyone is staying healthy and hopefully we're all slowly moving back to the operating room.
TRAVIS BLOOD: I am Travis Blood. I'm one of the Brigham and Women's Fellows, as Dr. Leversedge mentioned. I want to thank Dr. Blazar for being my mentor and I think together we're going to be able to convince you that in-situ decompression for chronic cubital tunnel syndrome is the right operation in many patients presenting like the case shown. So here's the case Dr. Leversidge already went through, so I'll skip through.
TRAVIS BLOOD: This type of compression can be classified as either a Dellon severe type compression or a grade three McGowan indicating persistent sensory symptoms with persistent atrophy and weakness as well as intrinsic dysfunction. So oftentimes in hand surgery, we have the procedure that is tried and true. However, in some cases we don't always have that one procedure that works each and every time.
TRAVIS BLOOD: This case is a perfect example of a case where it's not necessarily one correct answer, but I'm going to try to convince you that in-situ decompression is the right choice in this patient. So knowing that surgery is indicated in this patient, there are few options that come to mind. So the surgical options consist of in-situ decompression, anterior transposition and transposition with supercharged or N2 ulnar nerve transfer.
TRAVIS BLOOD: But in my mind, inside decompression is the treatment of choice. I've been trained by my mentors here in Boston that when deciding on a procedure, we first look at the level of evidence and what supports the procedure of choice. And there are multiple level one studies that support in-situ decompression as the treatment option here.
TRAVIS BLOOD: So I'm going to start this prospective randomized controlled trial done by Gervasio and the Journal of Neurosurgery in 2005 looked at 30 patients, randomized sorry, 35 patients randomized to each group looking at simple decompression versus anterior submuscular decompression. They found that there was no significant difference between the outcomes in the two groups. Looking at the Bisher score at six months and four and up to four years.
TRAVIS BLOOD: They also found that 80% of patients rated their outcome as excellent or good, and they had full return of sensation as well as motor in up to 33% of their patients. And another prospective randomized trial done by Biggs and Curtis, they looked at 44 patients, 23 in the decompression group and 21 in the submuscular transposition. Both procedures showed comparable clinical improvement, with 61% in the decompression group and 67 in the transposition group.
TRAVIS BLOOD: A subgroup analysis looking at the medium and high grade McAllan scores showed 82% improvement in the neurolysis group and 68% improvement in the submuscular group, indicating that patients were getting better with the submuscular sorry, getting better with the neurolysis over the submuscular transposition. Interestingly, they also found that there was no complications in the decompression group, but 14% in the transposition group.
TRAVIS BLOOD: Not to beat, not to beat a dead horse but another level one study by Bartels et Al showed similar results at one year, with 50% of patients getting complete resolution of symptoms and 80% having improvement. But this study also looked at the complications, and you can see that looking at a total of 152 patients, they randomized into two groups and they found that the complication was greater in the transposition group with a 31% complication rate versus 10% complication rate in the decompression group.
TRAVIS BLOOD: Similarly, looking at specifically at the complications of the two procedures, a recent retrospective study done at Brigham and Women's that was published in the Journal of Hand Surgery showed no difference in complications between the two groups, but a secondary surgery rate of 11.1% versus 2.5% for decompression. So this here just shows us that there's significant more complications in the transposition group.
TRAVIS BLOOD: Speaking of revision rates, the paper by Calfee is commonly cited by sceptics as a reason for anterior transposition over in-situ decompression. However, Calfee et al found that the predictors of revision were McGowan stage one, which is limited disease. Often these patients can be treated without surgery or patients following elbow fracture or elbow fracture dislocations, which is a totally different subset of patients that we have here.
TRAVIS BLOOD: To counter the Calfee et Al paper, there was a multicenter trial done by Song et al, showed a revision rate of 2.5% And there was also a study done out of Philadelphia by Osterman et al that showed a revision rate of 3.2% This labeled the operation of simple, of a decompression as a simple procedure with minimal risk.
TRAVIS BLOOD: So lastly, this brings the question of supercharging the motor branch of the ulnar nerve with the AIN. In other words, plugging a garden hose into a fire hose to improve intrinsic function. Sorry I think I skipped this. As of now, we'll let the colorful pyramids explain where we are with that reporting level four and five evidence.
TRAVIS BLOOD: It's too early to say it won't work, but there is still more evidence that is needed to prove that this is a good operation. Until now, I'll have to go with the author's comments that says post-operative improvement in intrinsic function in the study could be done to related to a number of factors other than the supercharged end to side motor nerve transfer, such as concomitant ulnar nerve decompression at the elbow or the wrist, and not sure if our colleagues will be arguing for the supercharge
TRAVIS BLOOD: agree with this statement, but will we'll see what they have to say. So this supercharged kind of reminds us of this little script. Hold on. There we go. So if you had to make a choice between a small surgery with the same outcome, lower complications, that is supported by level one evidence, what would you do?
TRAVIS BLOOD: And so, Dr. Blazar. It looks like we win again. Do I have? Thank you.
FRASER LEVERSEDGE: Great thanks, Travis. That was very nice. So I'm not sure what you're going to do without a quarterback next year.
FRASER LEVERSEDGE: So hopefully that, that, that brings up the level of evidence. So our next presenter from just not too far away down the street. Brian, are you there for? Yes, I'm here. Anterior transposition. Great get my screen up. He drew the first blood, but it won't be the last.
FRASER LEVERSEDGE: Biggest words from the guy with the chess pieces in the background. But it's a real chess metaphor, Phil, because there's only one King standing, if you look carefully at the screen. And that's why you're sitting down, Kyle? Well played.
FRASER LEVERSEDGE: Well played.
BRIAN FRENIERE: Can everyone hear me and see my screen? Yes great. So thank you, Travis, for that wonderful presentation. We're now here with the rebuttal as to why anterior transposition should be the choice of procedure for our patient. I'll briefly review the indications for this procedure, in particular some of the general techniques, some pearls and pitfalls for this procedure in particular.
BRIAN FRENIERE: A little bit about the outcomes and we've already heard a little bit about them. But then in this case, specifically, why anterior transposition? And I think Travis proved exactly what I thought he was going to, putting a lot of evidence out at us. But in our heart of hearts, is this really the right procedure and this is this what you would want for your family based on level one evidence alone?
BRIAN FRENIERE: So what are some consensus and consensus in a loose terms indications for a transposition? I think the majority of surgeons would note that it should be the procedure of choice for those with pre-op subluxation, subluxation appreciated during intra operatively during in-situ or planned in-situ decompression for a revision of a failed in-situ decompression.
BRIAN FRENIERE: Those who have had a prior significant elbow trauma as well as sharp transection and ulnar nerve at the level of the elbow or lengthening is required. What are the technical options? Briefly, there's the traditional pure subcutaneous and it's been modified. The Rosenwasser, it's described the adipofascial sling. There's also the subfascial or intramuscular technique.
BRIAN FRENIERE: And then the originally described pure submuscular technique. Some pearls and pitfalls. I think we've heard about some of these already, but taking care of for adequate mobilization along the length of the ulnar nerve as it crosses the elbow, avoiding the kinking that we saw earlier, but also taking care in diabetics or other high risk populations to ensure adequate blood supply to the nerve. Of course, not to overtighten in the tunnel that's created with either the facial or adipofascial sling or in the intramuscular tunnel, ensuring that the nerve glides with range in the elbow, ensuring that the branches are adequately mobilized so they don't tether, become tether sites for the nerve and then meticulous hemostasis
BRIAN FRENIERE: so a hematoma doesn't undo the good work. Now what can we say about this procedure? Well, I think despite what we've heard earlier, relatively low complication rates in the single digits and large studies with over 1000 patients, in the majority of these complication rates that I think we've heard about are focused around scar sensitivity. And there's evidence out there from Dr. Calfee's group as well, that at about two months, a lot of these, a lot of the morbidity is similar in situ as well as transposition.
BRIAN FRENIERE: And then I think also we've seen in large series that are contemporary and I think change from past low revision rates in the single digits as well with several years of follow up. But most specifically for our patient here, what do we see in terms of recovery in those patients with McGowan 3 ulnar neuropathy with decompression transposition alone? And I think if you look at some of the experts who are littered across these papers that I've outlined here and those patients who are followed for an extensive period of time, transposition has yielded very predictable results with low complication rates numbering in the low single digits with excellent results.
BRIAN FRENIERE: And we've seen that even in those patients with severe ulnar neuropathy, there's good recovery in terms of both sensory and motor function within the hand and I think that's something that we must consider when looking at the expert opinion out there that those pillars of the field of nerve surgery really have a predilection to transposition. So I think in terms of looking at the critiques we're going to get from both ends, I think we've already heard from the minimalists that the outcomes are the same and that we can always transpose later if we need a revision.
BRIAN FRENIERE: And I think looking towards the SETS camp that I think what they'll claim is that the advanced changes at the elbow are just too far to recover and that there's little downside to supercharging. So looking at each of those, I would propose that the best solution probably lies somewhere in the middle so the outcomes are the same.
BRIAN FRENIERE: I think Travis has outlined all four of these studies brilliantly and gone through them very detailed, but what are we look, if we pull that data and we look at studies that have only with some more prospectively prospective studies and what have they shown in a pooled meta analysis? Well, if we look at that, in 10 studies that have 449 compressions, 342 subcutaneous, 115 submuscular,
BRIAN FRENIERE: while there wasn't a statistically significant difference, there was definitely a trend towards improved clinical outcomes with transposition as opposed to simple decompression. And I think this forest plot demonstrates that nicely that while the evidence might not be there, probably due to the low numbers, there's definitely a trend towards transposition being superior in terms of clinical outcomes when we look at a larger series.
BRIAN FRENIERE: And I know Travis has already highlighted this already, but that at a minimum five year follow up and if we follow these patients for a long time, the outcomes for insight to have a higher revision rate and studies that are out there in the literature, this one coming from Dr. Hutchinson. And I would harken back to the long term follow up that I think is required for a lot of these patients.
BRIAN FRENIERE: Many of the in situ studies have a short term follow up but if we follow our patients out over a long period of time, they have good outcomes and there are few reoperations as this study coming from Dr. Jupiter. If the argument is that you can always transpose later, I think that the outcomes are not as good and we've seen that in multiple studies, not only the one from Dr. Calfee, but also this one in a neurosurgical journal looking that of those patients who underwent transposition for revision, less than half had improvement in their pain sensory motor function.
BRIAN FRENIERE: So don't think that it's always true that you can easily transpose later and have good outcomes. Well, looking to the SETS folks, maybe that it's just advance changes will not recover the procedure only at the elbow. And I think we've see in these long term follow up studies from those pillars in the field that that's not true
BRIAN FRENIERE: and we do have improvement in our patients with severe changes with just decompression and transposition alone at the elbow. And I think we've already seen this article highlighted by Dr. Leversedge, but we just don't know what to say about that and whether it's
BRIAN FRENIERE: the transposition at the elbow, that's really the driving factor in the studies that have looked at SETS,
BRIAN FRENIERE: we don't know, and I would advocate that until we do know, it may not be worthwhile. As always, there's little downside to supercharging, but they're in surgery. There's no such thing as a free lunch and complication rates, cost and whatnot must be higher for a procedure that takes longer and is more invasive. So while there's a nice new shiny car Ferrari out there, I think that the tried and true method that we've developed with anterior transposition always trumps that and ends up on top.
BRIAN FRENIERE: So I appreciate your time and I hope you'll consider our argument in favor of interior transposition as the favored approach for chronic ulnar neuropathy with severe changes in the hand.
FRASER LEVERSEDGE: Great thank you, Brian. I think that was Tom Brady's truck trying to leave Boston really quickly. Foxborough. So our last, our last, our last
FRASER LEVERSEDGE: speaker. Tyler, are you there? You can take over the screen.
TYLER EVANS: Absolutely give me one second here. Can everyone hear me? Yes, yes. OK, good. All right.
TYLER EVANS: Thank you for allowing me to present today and thank you to Dr. Moore for her expertise on this topic. I'm going to present to you the top five reasons to do an ulnar nerve transition and an AIN supercharge. So we heard the arguments from the other two options for this patient with chronic ulnar nerve compression with intrinsic atrophy. But I don't believe that those options are enough for this specific case.
TYLER EVANS: He has, he's an avid guitarist requiring strong intrinsic to do something he loves. He has atrophy and weakness already and with EMG findings of an axonal injury. Luckily there is another option, and that's the supercharge. In the last decade AIN supercharged nerve transfer has gained a lot of attention for a treatment of this specific issue. There's a lot of naysayers still, but I'll give you five reasons why I think that this is a good treatment option for this specific pathology.
TYLER EVANS: So what is a supercharged nerve transfer? Supercharging refers to a transfer of an expendable distal motor nerve to the side of an injured recipient nerve. The donor distal end is co-apted through a perineurial window to enhance regeneration of that injured nerve. As you can see, the traditional end to end or end to side transfer requires transection of that recipient nerve which takes away any chance of proximal regeneration from the injured nerve itself.
TYLER EVANS: But the supercharged underside allows for both proximal regeneration and the additional regeneration from the donor. So why supercharge the ulnar nerve in this case? Well, I think the answer is pretty clear. Do you want the Ford Pinto with custom wood paneling or do you want the 1967 supercharged Ford Mustang, Shelby GT 500 with 770 horsepower? Who doesn't want that additional power?
TYLER EVANS: So when do you do a supercharger AIN transfer and cubital tunnel syndrome? Well, I think you have to have physical exam findings, obviously, of compression and intrinsic weakness, mostly a diagnosis from physical exam but then you look at also the nerve conduction studies. They must have evidence of muscle denervation, which can be seen with positive fibrillations and also reduce CMAPs.
TYLER EVANS: And then number three, the AIN must be a viable donor, which you can see on EMG, for example, in a CATD1 radiculopathy, the AIN may not be useful. So the first reason, we all know the old phrase, time is money but in terms of nerve injury, time is muscle. So the more distance to travel, the more time. The more time it takes, the more muscle loss, the more muscle loss, the less function.
TYLER EVANS: Functional recovery is related to maximizing the number of motor axons and minimizing the time to rennervate the motor endplates in muscle and too much time passes. There's an irreversible loss of those motor endplates through degeneration and fibrosis and nerve damage. Schwann cell support diminishes, leading to apoptosis and loss of trophic support. Both of these greatly impact the functional recovery.
TYLER EVANS: So we all know that the nerve regenerates at a rate of about one millimeter per day, one inch per month, one foot per year. Irreversible muscle atrophy has been shown to occur anywhere from about a year to 18 months. So proximal insults to nerve greater than a foot away from the endplates are at risk. The terminal AIN branch has about 600 axons and is very distal. If we are able to add those motor axons and shorten the distance to the motor end plates and we can shorten the time to regenerate those distal intrinsic muscles.
TYLER EVANS: You can clearly see in the bottom picture that the terminal axonal sprouting and reinnervation by the increased fluorescent staining in an injured recipient nerve. So reason number two, it's an easy dissection and it's a very consistent anatomy. So you can see here, this is the anterior interosseous nerve transfer first described in 1997. You can see the terminal AIN branch here going to the pronator quadratus and the approximate harvest site of the ulnar motor portion.
TYLER EVANS: This is a great anatomical picture here that shows the ease of dissection under the flexors to expose the PCU and the AIN with the ulnar nerve nearby, feathering through the PCU with a bipolar until the AIN starts branching, you can get an adequate length for a tension free repair, which is important. The recipient ulnar motor component is shown here. This can be etched in your memory pretty easily to know where the motor component is.
TYLER EVANS: If you just remember sensory motor sensory, meaning you have the dorsal sensory branch coming off the ulnar nerve most ulnarly, then the motor component, then the rest of the sensory component of the ulnar nerve. It's easy to remember: sensory, motor, sensory. This is just a depiction of the AIN transfer to the ulnar motor portion with no tension, usually done about 9 centimeters proximal to the wrist crease. It's very important here to follow good microsurgical technique and especially not putting sutures through the axons themselves.
TYLER EVANS: You do create a perineurial window, but sutures should only be placed through the epineurium. Poor technique, suture knots within the axons and too much tension will lead to poor outcomes. Reason number three is you have improved functional and DASH outcomes according to some studies. This study here, basic science, showing that when looking at muscle force after super charge transfer, when you transect the donor nerve, the specific force actually decreases.
TYLER EVANS: So you will likely have some proximal regeneration from the release and transposition itself only. But this gives support that the super charge can help give you additional renervation and muscle recovery. So this study by Dr. Moore and Dr. MacKinnon with 55 patients showed overwhelming majority of patients improved their MRC category, had significant improvement in their DASH scores and increased their strength of an averag of about 3 pounds of force.
TYLER EVANS: This study showed that about 84% of supercharged transfers showed intrinsic recovery, compared to about 38% in the non-supercharged group. And this study in 2019, a systematic review recently published reports that grip and key pinch strength improved 202% and 179% respectively, and that 92% of patients recovered intrinsic function after supercharged AIN transfers.
TYLER EVANS: And in this study, recently published January 2020 by Dr. Moore, Dr. McKenna shows that you need about 70 to 80% of motor neuron loss before you have functional loss. So really what we need then is to get about 20 to 30% reinnervation for any functional recovery. So reason number four, there's minimal donor morbidity, really. We believe that you should release Guyon's canal. On this case as well,
TYLER EVANS: due to the double crush phenomenon that was described in 1970s by Dr. Upton, the nerve becomes especially susceptible to compression at another site when it's compressed elsewhere. So this incision is just an extension of your Guyon's canal release. There's minimal traumatic dissection as you stay mainly within the loose areolar plain under the FTP and you just feather through the pronator quadratus until the AIN begins to branch.
TYLER EVANS: Pretty simple. And when we talk about the denervation of the pronator quadratus, I mean, who really cares, right? How many of you guys actually do a meaningful repair after a blasted distal radius of the pronator quadratus? I don't think many people do. And this study shows that comparing repairing the PCU really has no difference in DASH scores, range of motion or pronation, post-operative pain or complications at the 12 month mark after distal radius fractures.
TYLER EVANS: And other studies have also shown denervation of the pronator quadratus has no effect on postoperative pronation. And then the last reason; I wouldn't be a plastic surgeon if I didn't have to mention Cosmesis. And so do your patients really want atrophied, weak and aging hands, or do they want young, strong, youthful hands? Even Michelangelo knew the importance of strong youthful function,
TYLER EVANS: functional hands. You can see a very strong first dorsal interosseous in both his painting, the Sistine chapel and also in the statue of David. So again, here are the top five reasons I think you should consider supercharging with AIN. Time is muscle. It's an easy dissection and consistent anatomy.
TYLER EVANS: You get improved functional and DASH outcomes, minimal donor site morbidity and improved Cosmesis. In conclusion, the case presented showed a patient with chronic ulnar nerve compression with weakness and atrophy, and somebody who uses his intrinsic muscles very often in a, you know, avid guitarist. He has EMG with positive fibrillations. Our recommendations are that this patient would most benefit from complete decompression and an AIN end to side supercharge transfer to the ulnar component.
TYLER EVANS: Thank you.
FRASER LEVERSEDGE: Great thank you, Tyler. I'm going to take over the screen here for. Well, those were fantastic presentations and I think as our next step here, we do want to hear a little bit from the faculty as we've had three methods of treatment.
FRASER LEVERSEDGE: But as we know, not everyone's the same and I'm curious with, with our index case here, we'll have a couple of topics to discuss. And I wonder from Doctors Moore, Dr. Eberlin and Dr. Blazar, as you've presented your cases and your and your rationale for treatment, are there, are there things that you consider in your preoperative assessment and I would include age in this as to how you might take care of this patient with intrinsic atrophy in a compression neuropathy, not in ulnar nerve, higher ulnar nerve injury, but a compression, neuropathy, anything in the preoperative assessment that you use to make a decision either for your treatment of choice that you presented or any of the other treatments.
FRASER LEVERSEDGE: For example, preoperative assessment of with ultrasound or specific testing that you might consider, such as with the EMG. Phil, any, any comments?
PHILIP BLAZAR: Uh, sure. Uh, first of all, I think all three Fellows did a nice job, so I want to compliment them on that. Um, you know, one of the most important things for me, and I'm just going to pick one to answer your, your multi-part question Frazer, is really trying to get a sense of the timing.
PHILIP BLAZAR: So I think the two things that have really predicted in my anecdotal experience, recovery of intrinsic function or length of compression, which can be very hard to estimate, but sometimes with a careful history, you can get a sense of it. And then age of the patient is, as you said, you know, nerve things, nerve pathology in general. Recovery really is very dependent on the age of the patient.
PHILIP BLAZAR: And, you know, it almost goes by, by 20s. You know, if you're, if you're under age 20, almost any nerve pathology with a reasonable solution will have a good result. 20 to 40 is still pretty good. 40 to 60 is favorable, but not great. You get to be over 60, and our neuroplasticity and our biologic capability of regeneration in my hands starts to diminish.
PHILIP BLAZAR: And you get to be over 80,
PHILIP BLAZAR: and you know, for most people you're talking about pain relief with most nerve surgeries. So, so two things that I try to assess, age is easy to assess, chronicity is hard to assess right? So Tyler mentioned.
KYLE EBERLIN: Oh yeah, comment about that. I agree with everything Phil said. I think ultrasound is really helpful in the office for this particular type of patient because you can see in real time if there is subluxation or perching, and I have found that if it if that is happening and you're going to talk to the patient about transposition, it makes that discussion a lot easier
KYLE EBERLIN: if if they're looking at the image with you and they're seeing their nerve move into the medial epicondyle, you can explain the logic behind transposition and why it might be something that's effective. So I think in addition to the time course which Phil mentioned, knowing what is going on with the nerve, is it just compressed like with an anconeus or is it really mobile or or is is the is the movement of the nerve something that's causing this this ulnar neuropathy?
KYLE EBERLIN: So I think that is critically important for cubital tunnel syndrome.
FRASER LEVERSEDGE: I would I'm going to jump in. I would agree with Kyle. I'm interested in what other people think in particular and we'll start with you, Kyle. Most patients that I see, I don't have too much trouble on physical exam assessing for subluxation of the ulnar nerve. I agree that there are studies out there that say we may not be so accurate, but my impressions, I think, are backed up in the operating room and actually physically looking at the nerve.
FRASER LEVERSEDGE: So I think it's the minority of patients that I have trouble assessing that. And I'm interested in what other people think about the ability to assess for subluxation in the office.
TYLER EVANS: I'm going to jump in then I want to ask Amy because I think Amy's opinion will be very valuable here. But I think when the nerve is is clearly subluxing, anyone can tell.
TYLER EVANS: I could take a first year medical student and they could figure that out. I think the challenge is when the nerve is just perching a bit and we all get in the operating room and you're planning to do an in-situ and you're moving the elbow and you're like, gosh, I don't know if I should transpose it or not, even if you're planning to do an in-situ. So I think the cases where there's some gray area where it's not obvious, that is when it's it's even more helpful to really visualize it.
FRASER LEVERSEDGE: OK Amy. Amy, do you want to weigh in for a second there?
AMY MOORE: Yeah I mean, I don't want to disagree with anybody. I don't think age of the patient matters at all. When I treat patients with nerve injuries, I take it into account of understanding it's going to take longer. I mean, there's been every rodent study to show that nerves of older rodents regenerate slower
AMY MOORE: and I think that's in humans too. But I don't change the procedure I'd offer for somebody based on age. The other thing that I use preoperatively that's important to me is the electrical studies and not so much time. It's because of that graph that we showed when we were discussing our nuances about this is that patients will have horrible atrophy and they'll say like, oh, I just started feeling weak a month ago.
AMY MOORE: So I don't trust patients to understand how bad is that compression to lead to loss of fibers that's going to finally make them fall off from having a functional outcome. And if we can just do something to get them back on the cliff where they have function. So Tessa Gordon did this study out of Edmonton at the time and showed that you can lose 70% of your motor neurons and still have normal function, but you lose 72% and you drop off completely.
AMY MOORE: And so I think understanding time point is maybe a less of an importance is to determine, OK, well, what can I do about it? And so then that becomes as surgeons, what can we do and the EMG will show fibrillations, which will show that the muscle is alive or not. And if there's no fibrillations and you have atrophy, you're not going to supercharge because it's already too late and so that's how I develop my chronicity.
AMY MOORE: Whether I use ultrasound, I don't have access to that so I don't, I think that that's an intraoperative decision that I make. But if I had it as a tool, potentially, but I do think the preoperative assessment of these patients to know what you're planning to do matters.
FRASER LEVERSEDGE: Warren, you're going to, you're going to say something earlier.
WARREN: Was just going to ask for Kyle or anybody that does ultrasound, does the cross-sectional diameter or cross-sectional area of the nerve come into play in your decision when you're going to decide?
WARREN: Or is it just you're using the ultrasound to see if it subluxes?
KYLE EBERLIN: Um, you know, I know that's been described and certainly John Fowler has done a lot of great work on that. I look at it, but to be honest, it's not something that I use to decide about my technique. So you're doing a dynamic study looking for hypermobility or subluxation of the nerve? Primarily primarily.
KYLE EBERLIN: And, you know, frankly, as I said earlier, I think it really gets the patient on your side and they get to see what's going on. I show them on the imaging, so I think it becomes a more interactive consultation and some of these patients who, you know, like the patient Amy mentioned, who comes in like this one right here comes in. So it's been going on for two weeks.
KYLE EBERLIN: And you look at their hand, you know that's not possible. It helps you to kind of educate them and it just gets them on your side a bit more.
FRASER LEVERSEDGE: Right so distal ulnar tunnel decompression that Tyler mentioned. Kyle anterior transposition. Any role in your sort of perspective of of somebody with intrinsic atrophy, any role for distal ulnar tunnel decompression without known pathology at the wrist, i.e. ganglion cyst, et cetera.
KYLE EBERLIN: I think if the EMG shows something there, obviously you should target it and that's a good indication to do it. If the EMG does not show you something, I think it's kind of dealer's choice and I will say parenthetically, I perhaps become a bit more aggressive about thinking about it if the patient is young and starting to get some intrinsic atrophy.
KYLE EBERLIN: But I do not know the answer about when objectively it's required or it's very difficult to even prove if you were to do it, whether it's made a difference.
FRASER LEVERSEDGE: How about if you do a set transfer? Is that decompression is routine for you also?
KYLE EBERLIN: Yes, that's that's part of the procedure. And I believe that you need to release all of the the compressive forces of the ulnar nerve as it sort of wraps around the hamate.
FRASER LEVERSEDGE: And Phil? So starting with the last one, when
PHILIP BLAZAR: I do a sets, which I almost only do for a laceration of the nerve, I will also decompress the ulnar nerve distally. But but I think the two pathologies are different. You know, I think a a lacerated or otherwise completely disrupted nerve, I think the pathology is very different from a nerve compression.
PHILIP BLAZAR: But but. You know, it's also interesting, at least with the neurologists and PM&R docs who do the EMG excuse me, do the electrodiagnostic testing in my practice, I have to specifically ask them about the distal ulnar nerve. I don't think most of them will do studies that are specific enough to to pick up if there's two sites of compression there.
PHILIP BLAZAR: So, so I find that only helpful if I ask and and so, you know, and I will if I'm the one ordering the test, I frequently if they seem to have distinctly more intrinsic dysfunction than other dysfunction, I will specifically ask them to look at that. And I've been surprised that a moderate percentage of the time they will find something and I will decompress it. So the you know, the answer is I don't know what the answer is because I don't think we ask the questions often enough.
PHILIP BLAZAR: And so anyway, those are my thoughts about the about the ulnar tunnel.
FRASER LEVERSEDGE: Amy, just Phil brought up a point there, and I mentioned it earlier with Steve Moran's paper and follow up. Do you see much of a difference between an ulnar nerve, high ulnar nerve injury compression type injury versus a chronic compression neuropathy at the elbow, any different from how you manage the nerve distally?
AMY MOORE: I don't do anything different, truthfully, whether it's a transection or a severe compression, they get a super charge. I know there's arguments that I should go into end, but because of my science, I'm biased to not and I've really been happy with the results by doing a super charge looking at my patients. Um, so I also, though, really, truly believe in the double crush syndrome, right?
AMY MOORE: And think that if someone has severe compression proximally, they're more inherent to compression distally. This has been thought and discovered a long time ago, 1970s right? So if I have somebody and I treat the patient and what the patient needs is more, then I'm going to give them the one surgery that's going to cover it all. And so, yeah, maybe aggressive, maybe not.
FRASER LEVERSEDGE: How about the high ulnar nerve injury with a patient with a Martin Gruber interconnection? Is that patient get a transfer distally?
AMY MOORE: They do. They do. Because they even those with the Martin Gruber where you're just like, oh, and it really throws you. I don't I don't think that PQ matters and I think those ulnar intrinsics you're just creating like a third, um, like, I mean, this is a sort of a weird way to say it, but think cassettes creates a Martin Gruber, right?
AMY MOORE: So you get two sources of axons and motor neurons at the spinal cord level filtering in to to do the motor endplate reinnervation and we know after any injury that there's never a complete 100% reinnervation of all the motor end plates. That's why we have fibrillations that last much longer than recovery. And so the idea is to get as many sources of axons to those muscles to give it the best potential.
PHILIP BLAZAR: No, I'll agree with Amy on that and I don't have her experience of doing an excuse me distal AIN to ulnar nerve motor transfers, but I happen to have done a couple of my early ones in people with that Martin Gruber and those those folks do better than anybody else because they do have the multiple sources. And so, you know, that person with the known high ulnar nerve injury who, you know, can do can do a demonstrate a little bit of intrinsic function in the ER, you know, in my, in my hands.
PHILIP BLAZAR: You want to do that there because because they're going to get to that 70% motor neuron function much more easily than other things.
FRASER LEVERSEDGE: Right so so, Phil, while you're while you've got the microphone, anything you mentioned inside your decompression, but no one mentioned endoscopic in-situ decompression. I've found that there's been some concerns about appropriate use of endoscopic methods.
FRASER LEVERSEDGE: You may miss the sort of the aponeurosis and the deep portion of the FCU and even more distally where you can still have tethering of the ulnar nerve between the heads of the FCU. Any thoughts about endoscopic for this patient, or would this be a mini open or a reasonable incision for somebody with intrinsic atrophy that you don't want to leave anything behind?
PHILIP BLAZAR: The only experience I have with endoscopic is in a cadaver so everybody should take what I say with a grain of salt, you know? How did the patient do? No complaints. You know, so my complication rate is zero. So no. So there is a you know, as everybody knows, there's a moderate body of literature on endoscopic decompression and
PHILIP BLAZAR: but not a lot of, you know, level one studies comparing not any level one studies that I'm aware of comparing to the more standard, although they may be out there. And I do think, like with any endoscopic technique, there is a concern for what can't you see? And so I obviously haven't gone to doing endoscopic techniques because I said the only one I've done is in a cadaver.
PHILIP BLAZAR: So, you know, maybe others have more experience and can comment on it. But I guess I would say I share your concern. I also think that you can do, you know, a endoscopic release and go 8 centimeters above the epicondyle and 8 centimetres below the epicondyle through a pretty small incision. So it may be a little bit of the triumph of technology over reason, but I'm interested in others comments.
FRASER LEVERSEDGE: Kyle or Amy any, any experience with endoscopic.
KYLE EBERLIN: I don't have any experience with endoscopic other than a cadaver also, so I'm not the best person to comment, but I am either technically inadequate to do it or I'm petrified of cutting the nerve or an MACB branch. And I just, I mean, I think the first time that ever were to happen, it would just be so catastrophic that I just am not willing to consider it. And I have taken care of a few patients who've had ulnar nerve injuries from endoscopic release.
KYLE EBERLIN: So that that shaped my perspective.
AMY MOORE: Yeah, that's, that's the only ones I've seen are the ones that I've fixed from somebody else's damage. So I'm just biased. Like I haven't been able to celebrate other people's success with that. And that's the same thing at the risk. Um, you know, my, my partners at Ohio State do a lot of the endoscopic carpal tunnels and I'm just like, well, I'll never do it, but I'm glad that they do it so well.
AMY MOORE: And so, you know, it's great, but I just haven't been so biased to treating people's unfortunate, um, complications.
FRASER LEVERSEDGE: Great and and Phil, just since you were the in-situ person, do you, do you supplement the concerning nerve that's starting to perch a little bit with any form of trying to deepen the, the, the cubital tunnel with a partial medial epicondylectomy or anything along those lines that have been described.
PHILIP BLAZAR: I do not. So if I have concerns about nerve instability and, you know, I certainly have a handful, no pun intended, of people who of mine who have gone back for subluxation that either didn't pick up on interop or it developed post op, but but I transposed the nerve, you know. So if I have a real concern about instability, I transpose the nerve. I have done medial epicondylectomy some in the past.
PHILIP BLAZAR: So it's not that I have zero experience, but but it's not part of my armamentarium at the moment except for perhaps in some unusual situation.
FRASER LEVERSEDGE: Right so anterior transposition. Kyle, you spoke to anterior transposition. Any preferred method?
KYLE EBERLIN: Yeah, I think you were just about. That wasn't. That wasn't supposed to show you or lead you on in any way?
KYLE EBERLIN: No, I really like the adipofascial flap that was described by Mel Rosenwasser. from JHS and there are a few reasons that I like it. You know, nerves like to be around fat, nerves like to be around vascularized tissue and that fulfills both of those roles. But perhaps most importantly for me, it really provides a long runway for the nerves. So that I think in my practice it's a bit less likely to get the zigzag deformity because it's providing basically a shoe for the nerve as it runs throughout the entire length across the antecubital fossa.
KYLE EBERLIN: So as you can see in the picture, which is quite well shown, I think it's a nice flap. It's very, very easy to do. You do have to be careful of the MACP which runs kind of in it. And but other than that, it's, it's my preferred technique for transposition.
FRASER LEVERSEDGE: So, Amy, with this patient, with, with chronic compression, neuropathy and intrinsic atrophy, what is your go to in terms of transposition portion of the case?
AMY MOORE: Yeah, I do that subfascial. I don't do the whole intramuscular thing that I learned from Susan McKinnon, but I definitely use the fascia and try to get it into a straight line. I'm most concerned of the distal kinking at the FCU and that there's the fascia that comes through there. So I basically release all fascia tethered for about 3 centimeters along the bone along the ulnar.
AMY MOORE: And so I don't allow there to be any distal compression. And then I put the arm through full range of motion to make it. But I'm most worried at that distal than I am proximally so I spend a lot of time fussing there.
PHILIP BLAZAR: Yeah, I agree with that. And I often will dissect out that first branch of the FCU, which you can see here, even back into the ulnar nerve a bit, just to allow that the nerve to lie a bit straighter.
PHILIP BLAZAR: I think that can be a very helpful trick. Totally agree.
FRASER LEVERSEDGE: And it looks this is this is a video of my patient, but it looks like the nerve is brought really anterior here. But this is just the adipose fascial flap being retracted anteriorly. But the point of the video is really to show the distal decompression here and to Amy's point, I think that's that's a really critical aspect of our procedure.
FRASER LEVERSEDGE: And it's oftentimes a worrisome area because we we sort of don't want to spend the time to to dissect out the motor branch and to really free up the nerve. And ultimately, we, we probably add to the potential for more distal nerve tethering. Phil, Phil, any any preferences for transposition of choice if you were to, because obviously you're insights you may not have worked or you had to go back or if you found a nerve that was unstable, what would your preference be?
PHILIP BLAZAR: Uh, depends on the patient. So one of the issues, Frazer, that you alluded to earlier is that one of the contributors to ulnar nerve pathology at the elbow is the superficial nature of the nerve, and so somebody without a significant subcutaneous layer of fat, I do not like to put the nerve under, you know, dermis with a few fat cells around it. I don't think that's healthy for the nerve.
PHILIP BLAZAR: So in that situation I will put the nerve submuscular and I tend to do it with a fascial lengthening. On the other hand, if someone has a, shall we say, more than their fair share or their fair share of subcutaneous fat, I will do a subcutaneous transposition. I completely agree with Amy about and you about the distal aspect being the area where I worry about the nerve not, you know, being kinked and having an abnormal plane.
PHILIP BLAZAR: And so I spend a lot of time on that distal FCU.
FRASER LEVERSEDGE: Right. And then Amy's, just any pearls for distal and ulnar motor transfer. If this was to be the case, and Tyler did a great job showing us the anatomy. You know, one of the questions is, do you need to dissect out the ulnar motor branch? You do an episiotomy. Any pearls of wisdom for securing your repair, for example?
AMY MOORE: Yeah, sure. I mean, I think as I've done this more and more, I have refined how I do this. But I think what's really important is to go enough proximally and release the muscle belly off the ulna so that you can dissect the AIN, not just distally into the muscle to get to where it's branching, but proximally so because there's all of the AIA, the artery that can kink it.
AMY MOORE: And so if you are addressing those vessels and pulling it over, you can have it lie under the ulnar nerve without any tension through full range of motion of the wrist. And so I'm not really trying to get it as distal. I just try to make sure I bring it over only to where it can hit the nerve. As for the nerve, I find the dorsal cutaneous branch that's my, that's my topography,
AMY MOORE: right? So as soon as I find ECU, I neuralize that proximally and I know the next segment is going to be motor. So early in my practice, yes, I did the skip dissections from starting distally, finding the motor branch and then following it, teasing it neurolysis with your eyes, whatever you whatever you want to describe it. But now I don't even bother doing that because the anatomy is all consistent.
AMY MOORE: Sensory, motor, sensory, that entire forearm. I had a patient with a stab wound up at the proximal forearm and we had to go in and look and it was still at that and be able to stimulate that, that topography was still solid proximally, so I'm pretty confident. The other pearl to make is the larger your epineurial window and then you spread over the perineurium the larger it is, the more fibers can sprout in.
AMY MOORE: And so that was shown beautifully in some transgenic animals where that the larger the epineurial window was, the more sprouting of axons in an inside manner. So I'm pretty aggressive on that. And then I just use the epineurium to suture loosely and direct, direct it like into it and I'm sewing the epineurium, but the fascicles are there spread to see the fascicles bulge but I don't injure the fascicles.
AMY MOORE: So I don't know if that, I don't know if that's very helpful or not, but that's what I do.
FRASER LEVERSEDGE: Kyle or Phil, any any comments about the distal nerve transfer? In just a minute or two we have left.
KYLE EBERLIN: Not really. I think Amy highlighted it and so did Travis exactly what
KYLE EBERLIN: I think about it.
FRASER LEVERSEDGE: Oh, this is just one Frazier one comment here. Sometimes we ask why our transfers don't work and this was actually a really interesting case that I came across. We actually explored what we presumed there was no real documentation for this patient. We did the procedure really for pain relief from the ulnar nerve at the elbow that had been unfortunately injured.
FRASER LEVERSEDGE: But she had no intrinsic function and we we explored what we presumed was a distal AIN to ulnar motor transfer as an end to end ultimately, and preoperatively she had no intrinsic motor function and prior to our neurolysis of the nerve transfer there was no response. And then we did a neurolysis and then intra operatively stimulated the nerve proximal to the transfer site and just found it was fascinating that there was now conduction.
FRASER LEVERSEDGE: So sometimes our nerve transfers don't always work for reasons that are beyond what we can actually see or look for, so it is it is something to consider as part of our technical ability and obviously for any of our, our procedures that we do, we always have to consider this as a reason why our procedures don't work. And then obviously distally, there's there's other reasons, there's other types of nerve transfers for the Fellows.
FRASER LEVERSEDGE: Hymie Bertelli's use of the branch to the opponent's transfer. If you think about your, your functional recovery for the ulnar nerve on the radial side looking for pinch and fine dexterity related tasks, the ulnar side more of the extrinsic function probably more helpful. So this may help to minimize the dilutional effect of a distal AIN to ulnar motor transfer and focus the recovery of the distal portion of the ulnar nerve.
FRASER LEVERSEDGE: You can see his work here. But I think we'll finish there. It's 7:00 our time here, 9:00 that time out on the east coast. And I think just to summarize, I think we all recognize this is a real clinical challenge. I think it's important to recognize that it really deserves a comprehensive assessment, whether you're looking for nerve subluxation or instability at the elbow, where you're looking for opportunities for nerve transfer, and being aware of whether or not you have an ulnar nerve injury or you've got a brachial plexus injury where your PQ may not be available or your AIN, I should say.
FRASER LEVERSEDGE: You want to honor attention to detail with your surgical technique
FRASER LEVERSEDGE: and I think that no matter what your decision for your preferred method of transposition, it's more about how you do it more likely in terms of your outcomes than than what you do sometimes. So again, optimize your nerve recovery potential is your goal and at the same time minimizing the inherent risks of your procedure. So I'd like to thank all of the faculty and the Fellows.
FRASER LEVERSEDGE: The Fellows did an outstanding job as they as they have been doing all along with this debate format. Thank you for your attention Warren and thanks for for your leadership and I don't know if you want to sign off for us here, but I'd like to thank everyone for your attention and thanks for participating.
WARREN: Yeah, I'd say thank you. Frazer you did a wonderful job as we anticipated.
WARREN: We had a good number of people tune in tonight or join us tonight and so I think that's outstanding. And the presentations were all excellent. I think we leave here probably still wondering what to do because they were all pretty convincing in their by themselves and then you listen to the next one and you say, well, maybe I should do something else.
WARREN: And the faculty mentors, the discussion was good. I think you also led your residents very well through this, so I commend everybody for the fine job tonight. We will rejoin Jerry and or I will send out the information for next week and we'll join again. Hope everybody stays safe and has a wonderful holiday weekend. Thanks, everyone. Have a good night.
WARREN: Bye bye. Cheers thanks, everyone. Thank you. Thank you. It's great to see you.
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