Dr. Clay Nuelle:                 Welcome, everyone. I'm Dr. Clay Nuelle at TSAOG Orthopaedics in San Antonio. Tonight I have the privilege of being joined by Dr. Matthew Smith. Dr. Smith is an Associate Professor of Orthopaedic Surgery at the University of Missouri and was a senior author on a paper entitled Superior Capsular Reconstruction Using Dermal Allograft Is a Safe and Effective Treatment for Massive Irreparable Rotator Cuff Tears: Two-Year Clinical Outcomes, which was published in the February 2021 edition of the Arthroscopy Journal. Matt, thank you for joining me today.

Dr. Matthew Smi...:         Oh, yeah. Thanks for having me, Clay. This is great, happy to be here. Appreciate it.

Dr. Clay Nuelle:                 Let's start with, basically, maybe just the basic background of the article, and the impetus for the study, and your guys' background with it, and then a brief summary of the overall findings.

Dr. Matthew Smi...:         Yeah, so it's a multi-center study, and actually, Alan Hirahara approached us and said he had been doing SCRs for a short time at that time. We started enrolling patients in 2015 for this. It was a multi-center study. It was actually going to have a third center, which unfortunately, had to drop out as we started enrolling patients, but it was really at the early times of SCR. In fact, Alan had spent some time with Mihata and really started thinking about ways to improve rather than doing the fasciculata. He thought about these thick acellular dermal matrix grafts, and had done some work, had done several on his own, and really wanted to enroll more patients and see if he could get the results out there faster.

                                                So he published one of the technique articles in 2015, and we initially based it on that, and said, "Look, let's start enrolling patients, and we're going to really be interested in imaging." So we really wanted to focus on the imaging afterwards. Alan's great with ultrasound, and said, "Let's see if these vascularize, and what happens long-term, and how patients do." Initially it was 10 patients per site, just to see how this whole thing would work. By the time we excluded some patients interoperatively, generally because of either irreparable subscaps, grade four changes in the cartilage, it was just down to 14 patients.

                                                And ultimately, after a couple of years, they really did well. It seems to be reliable for pain relief. Their VAs pain scores decreased significantly. ASES scores went from the 50s to high 80s. Forward elevation improved significantly from the 120s to 170s. Same score improved, acromiohumeral distance improved and really overall I think followed the trend of most of the studies that we're seeing with superior capsular reconstruction.

Dr. Clay Nuelle:                 Absolutely. I think it's really interesting. You touched on one thing that I thought was really interesting, that you guys did a great job with in terms of doing the ultrasound and evaluating the vascularity of the graft itself and that 93% of 13 of the 14 graphs had some evidence for vascularity at one year postoperatively. What factor do you think that plays in the overall function of the graft? And obviously in terms of long-term rotator cuff studies, there's a variable... We know variable healing rates with the rotator cuff itself, the native rotator cuff and now we're talking about an allograft here. And so do you think one of the primary factors in terms of healing and, or the function of the graft, obviously it's multifactorial, but you guys looked at that specifically. So what role do you think that plays?

Dr. Matthew Smi...:         Yeah, so I think the acellular dermis has been around for rotator cuff surgery for a long time and certainly these new grafts are quite a bit sicker. And there's something about the dermis in and off itself that allows for tissue and growth and angiogenesis. And what is interesting is that the size of the vasculature and how it appears on ultrasound decreases slightly with time, which I think is fascinating. It's like these initial robust blood vessels, at six months come in and they're really obvious and present on ultrasound. And as time goes on, they get smaller and more diffuse. There have been some studies, you have partners actually down there who have some studies on retrieval of what grafts look like and these acellular dermal grafts become a little more tendon like, in some areas become almost indistinguishable from native tissue.

                                                So I think it's important, and our study and a couple of other studies have shown that with time the acromiohumeral distance decreased, which I think is interesting. I mean, in terms of the graft, and what it's doing, and how it's healing. I don't have an explanation for that. I mean, ours went from initially six millimeters to eight millimeters at six months, seven and a half millimeters at a year. And then at two years, it was only 6.7 millimeters, slightly better than it was preoperatively. And you think, well, the graft is healing and vascular. Why would that change? I mean, what about that would change? So I don't have a great explanation for it other than the acellular dermis. I mean, just the nature of the dermal tissue and all of its structures and pores, I think lends itself to healing and becoming more like the host.

Dr. Clay Nuelle:                 Yeah, absolutely. I think those are great points that help try and better our understanding of how it heals and functions. A little bit into indications, I think anytime we get a relatively newer procedure or a procedure that is starting to maybe become more mainstream. Sometimes the indications tend to get expanded or the indications get to be applied to maybe a wider variety of things and was initially started. So you guys did a great job outlining that it was for massive irreparable cuff tears, but not with bipolar cartilage loss or grade four or five Hamada classifications. Or you mentioned a couple of patients fell out of the study because of irreparable subscap tear.

                                                Those are obviously the primary indications. Is there anything else that you think sometimes some people have indicated that maybe it's best for a patient that's less than 65 years old, or best for a patient that's more active, or in the editorial commentary that accompanies your guys' article in the journal? Those authors even recommend as low as Hamada grades one and two, and maybe not even a grade three. So in your practice, what are the things, do you have cutoffs, or do you have primary indications in addition to those factors that would lead you towards an SCR?

Dr. Matthew Smi...:         Yeah. And so primarily, doing shoulder, I feel like I have a pretty decent basket of tricks or a tool bag and comfortable doing reverses and tendon transfers and things like that. And so when you narrow it down, or I tried to narrow it down, I guess, you will get all of... There's lots of studies on SCR and a lot of them are pretty small, like ours, 20 patients ish, and they have fairly similar results in, I think the right patients. And so to your point, what's the right patient? I mean, for me, I think they have to have decent function. I know there are reports of them reversing pseudo paralysis and things like that. But when I look at patients who are going to benefit from one operation, as opposed to another, if I have a patient who truly can't raise his arm and has some arthritic changes, then for me, that's clearly a reverse. But if you have somebody who's in like the 120 degree forward elevation range, or they're above 90, they are active, their x-rays are basically normal except for maybe some superior migration. So no significant arthritis.

                                                Expectations. I think expectations play a huge role. What do they want to do? So their activity level. And then what are their symptoms? So if you have a patient who has relatively preserved motion, but overhead movement causes pain, or they get a lot of mechanical symptoms and acromiohumeral rubbing and clicking that bothers them. And patients who don't have a massive loss of external rotation, who would potentially benefit from something like a tendon transfer, they can't maintain their arm at their side in an externally rotated position. They have a significant lag sign. I think those set them up for requiring a more significant operation.

                                                I think in general, it's good for pain relief, it's good for patients who have preserved activity. Patients who have relatively preserved motion, we know if they go through a reverse, they tend to be less satisfied. Some of them lose motion and it just doesn't feel normal. And so I think if somebody has good overhead function and not a lot of arthritis, this offers a really good option.

Dr. Clay Nuelle:                 Yeah. I think those are really great points of a really ideal subset or population for this. Just a few technical points or to get your thoughts on. So one of the things you guys mentioned in the paper was that all the SCRs to perform a neutral abduction at the time of implantation. And some people have talked a lot about optimal SCR graft tensioning and the optimal position the arms should be in when it happens or the optimal tension the SCR should be under. And if it's not stressed enough, it won't function very well. And if it's too tight, then you have increased risk of tearing. So what do you think are your tips for teaching it appropriately and how you position either the patient or the graft itself?

Dr. Matthew Smi...:         Yeah. Those are great points. And I do see a lot. And it's funny, when we were first enrolling patients into this and everything was so new, [inaudible] up on the podium after they get a paper accepted and they've done like eight of them. And they're like, "You have to put the patient in 30 degrees of abduction." And it's like, "Well, wait a minute. We don't really know that. I mean, in the grand scheme of things, it's relatively new, and in the grand scheme of things there's a lot of papers again that have relatively small numbers like ours and they have very similar results." So I think it's more about patient selection. I have seen the studies about pre tensioning the graft, which I think makes sense bio-mechanically. But how much it changes or how much it applies to what we do clinically, I'm not sure if I know.

                                                So we went with neutral abduction just because as you watch this through a simulator, and we went into the lab and have done some things since in our Thompson lab up here at Mizzou. And just watching what happens when you put a shoulder in a simulator and you can really significantly increase the tension when you go from 30 degrees of abduction, when it's implanted and tension, and then bring the arm to the side. In the failures we had, one of them was from the medial side. And since that time, and reviewing MRIs, and having performed more of these, they tend to fail more on the medial side.

                                                Now thankfully patients who have a medial sided failure tend to do well. There's still some interposition, but I do think it's a significant stress in going from an abducted position to bring the arm to the side on the medial row in particular. So in terms of how much it functions, it's more of a static graft rather than something that has dynamic or pull or function like a muscle tendon unit. So I think the biomechanics of it are important. I just don't think we know enough yet to say you absolutely have to put it with the arm in this position or under this much tension or... But that Will probably evolve I think as more and more get done and indications probably get narrowed to more follow up as longer.

Dr. Clay Nuelle:                 Yeah. I think those are all terrific points. What do you think about over the top cuff repair or partial cuff repair in conjunction with the SCR? Some people doing some of those studies and some of those comparisons are coming out and the results seem to be a little bit of a mixed bag or a little bit variable. And even in some cases, the outcome stores and the patient reported outcomes are even a little bit worse in the cases where there's been a partial cuff repair or an over the top repair in conjunction with an SCR. Have you done many of those or what do you think about that?

Dr. Matthew Smi...:         Yeah. I haven't done a lot of that and sometimes to me it just comes down with a cost benefit. I mean, truly just in terms of cost resources when you're performing one of these surgeries. And then overall, how much better can you make certain things? So if you look at just doing a repair and then adding something to protect the repair, or doing a good partial repair, how much do you need to add? We have excellent long-term outcomes of partial rotator cuff repairs in terms of what happens to the shoulder and how well patients do. So for me, I tend to be a pretty simple guy and I think of, well, if I can do a good partial repair, their subscap is normal, and I bring the infraspinatus up, and they don't have a lot of arthritis depending on what they're looking for, can I add a lot by placing a relatively expensive graft? Can I change their outcomes a lot by adding one of these graphs and more anchors, and the other way around.

                                                If the native tissue is under a bunch of tension and I do some slides or something, I can get it to move a little bit, does it add much to try and sell it to the graft or sell the graft in different locations, or am I just complicating things? Am I putting tension on the graft in a way that there doesn't need to be, or in a way that has not been studied? So I feel like you can definitely try to do too much. And I think it's just, again, trying to maintain a specific goal. What do the patients want? What do they have when I enter the operating room? And how am I going to make them better?

Dr. Clay Nuelle:                 Yeah. I think those are all terrific points. I think one of the things, or a couple of things that Steve Burkhart has taught me is, there's probably more rotator cuffs that are repairable than maybe some people think, if you do some of the techniques like you mentioned with some slides and mobilization and things like that. But if you do those things and it's still under a ton of tension and you can't repair it, then what are you adding by really repairing that or repairing that is still under a lot of tension with the graft. And so I think that those are definitely really important points and nice technical notes with it. Matt, thank you very much for joining me today.

Dr. Matthew Smi...:         Yeah. Thanks a lot, Clay. Be well.

Dr. Clay Nuelle:                 Dr. Smith's article, Superior Capsular Reconstruction Using Dermal Allograft Is a Safe and Effective Treatment for Massive Irreparable Rotator Cuff Tears: Two-Year Clinical Outcomes can be found in the February 2021 edition of the Arthroscopy Journal or online at www.arthroscopyjournal.org. That concludes this edition of the Arthroscopy Journal podcast. As always, if you enjoy the podcast, please remember to give us a five star review on your listening device. Thank you. The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association of North America or the Arthroscopy Journal.