Dr. Justin Arne...:             Welcome everyone. I'm Dr. Justin Arner from the University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania. Today, I have the pleasure of speaking with Dr. Eddie Chang, sports medicine surgeon at Inova in Washington, DC. Dr. Chang was the senior author of the paper entitled Intermedullary Unicortical Button and All-Suture Anchors Provide Similar Maximum Strength for Onlay Distal Biceps Tendon Repair, which is in press in the Arthroscopy Journal and is currently available online. His coauthors include Donald Colantonio, Anthony Lee, Laura Keeling, Sean Slaven, Tarun Vippa, and Melvin Helgeson. Welcome Dr. Chang, and thank you for joining me.

Dr. Eddie Chang:               Thanks for having me, Justin.

Dr. Justin Arne...:             Yeah, I'm really looking forward to this. So first of all, congratulations on an excellent cadaveric study. I know it takes a lot of planning and really a huge amount of organization to pull off a study like this. So excellent work with that.

Dr. Eddie Chang:               Thanks so much. Yeah, it was a great study and I was very privileged to work with a bunch of residents from Georgetown and at Walter Reed. As well as the biomechanics lab at Walter Reed was gracious enough to help us perform this study.

Dr. Justin Arne...:             Yeah, it sure takes a whole big team and a lot of planning to get that going. So fill us in on how you came up with a study idea, and what do you think it adds to the literature and what was lacking before you took this on?

Dr. Eddie Chang:               Yeah. This is a study I've been thinking about for quite a bit now. When I was first started training, we were mainly doing distal biceps repair onlay, single decision with suture anchors. And then midway through residency, we began to do an inlay technique with a socket as well as the intramedullary cortical button and with an occasional interference screw as well.

                                                And then in 2015, there was a JBGS article that was published. Biomechanics study looking at the importance of preserving the radial tuberosity. And when they compared the technique of using a socket or a trough compared to an onlay type technique, they found a significant decrease in the moment arm of supination. And so that got me thinking, why are we actually reducing the radial tuberosity height if it actually is important in preserving supination strength?

                                                So over the past five to seven years, there has been increased interest in using intramedullary unicortical buttons. Dr. [Siebenlist] out of Germany has been looking at this quite a bit and has published his technique on it, as well as some biomechanical studies showing good results, both clinically and in the lab for this. And with the advent of all-suture anchors, we wanted to actually test this and compare it to the intramedullary unicortical button.

Dr. Justin Arne...:             I love that. That's a great summary of the literature. That's excellent. Can you tell us a little bit about your study design? I noticed that you really paid a lot of attention to bone density and tried to get younger patients. So tell us a little bit about that.

Dr. Eddie Chang:               So, yeah. Again, that's a great point. When we did this study, we really wanted to mimic as best as we can the population that gets distal biceps ruptures, which are mostly male patients in their forties and fifties. And we measured the bone density to make sure that there was adequate bone stock to perform these surgeries. Took a little bit of time for us to get the specimens. And then, but once we did, we were then kind of ... we had a matched pair. So one arm was getting the unicortical button and the other arm was getting the all-suture anchors.

Dr. Justin Arne...:             Yeah, that's great. I appreciate that explanation. Can you tell us a little bit more. I know you mentioned it about the surgical technique utilized and your thoughts and any more information that you'd kind of read about, as obviously you know the literature well versus onlay and inlay and single and dual incision techniques in your work experience and what you've seen. Anything related to that I think would be really helpful for the listeners.

Dr. Eddie Chang:               Yeah. So for both the intramedullary button and all-suture anchor technique, the goal was to, even though this was a cadaver lab, was to mimic a single incision technique where you have the forearm maximally supinated to insert the anchors, as well as to secure the distal biceps tendon down. We did separate the anchors by 12 millimeters, and that was just based off of previous studies that did look at all-suture anchor, as well as dual intramedullary unicortical buttons as well. They separated by 12 millimeters. And my guess is that, the radial tuberosity is about 22 to 24 millimeters in length, and that's kind of a good distance to where you can achieve a maximum footprint spread proximally and distally.

Dr. Justin Arne...:             Yeah, that's great. Tell us a little bit more about what you used in your practice. And you mentioned the supination strengthen, and do you think you were able to recreate this with some of these techniques? And some of these anchors are double loaded, do you use both sutures from the double loaded? Tell us a little bit about your approach to this personally.

Dr. Eddie Chang:               Yeah. So currently I've been using ... Well, let's go back. When I started, I was using the [inaudible] technique, so that was a far extramedullary button. And I also drilled a trough. Now, whether it's a seven or eight millimeter trough as well, I did not use an interference screw, and that's how I was trained.

                                                And over the last year or two as more data came out about going back to the onlay technique with unicortical buttons, I've switched over to using metallic single unicortical buttons currently. Our facilities have not approved the all-suture anchors. And when that happens, I'm excited to try those out.

                                                When you asked about recreating supination strength, the biomechanical studies have shown that preserving the radial tuberosity height helps improve supinate strength. Now, clinically, that will be a good study to look at moving forward. And I think that's something that at our institution we're going to look at. And then lastly, when the anchor is actually, the ones that we use are the 1.35 millimeter all-suture anchors are actually single loaded with a 1.3 millimeter tape. And so, if it was double loaded, I would remove one of them, as that's a lot of suture to go around a tendon.

Dr. Justin Arne...:             Yeah. Good point. I always wonder, if you're putting so much suture there, maybe you're having better strength, but if you want it to really heal along the bone, then you're right. I think that you have to have some tendon there. So tell us a little bit more about, do you like the tape? I think it makes sense to maybe have a better fixation. And tell us, do you prepare the tuberosity at all? Or what are your thoughts?

Dr. Eddie Chang:               I like the tape. I think anything that gives a broader suture, I think gives you less chance of cut-out. It also, in terms of tying knots, it's easier on the fingers, as you know. And so for me, my personal preference is to use a small tape whenever possible. Yeah. With regards to preparing the bone, because you're not creating a trough, you do need to spend a little more time preparing the radial tuberosity to create a good environment for it to heal. So I generally will use a key elevator to prepare that area and use a mallet to kind of gently tap the radial tuberosity with the elevator to almost like a shingle effect as well. And that just, I don't know whether that's proven to help, but it's just something for me to make me feel a little bit better when I'm doing any type of onlay technique. And that's similar to if I'm doing a proximal biceps tenodesis as well.

Dr. Justin Arne...:             Right. That's a good point. I know our mentor Dr. Bradley talks about that in the proximal hamstring, fish scaling it. And I think that's a good trick. So getting back more to your study, can you give us a summary of your results and is it what you expected? And just give us your thoughts about the results.

Dr. Eddie Chang:               Yeah, I think probably the main takeaway, there was no significant difference with maximum load to failure between the unicortical intramedullary button, as well as the all-suture anchor repairs. And when you actually look at maximum displacement after cyclic loading, the all-suture group performed better. And that means that there was less displacement compared to the unicortical button. And I think that's very important when we're talking about onlay technique as more displacement likely leads to a less potential for the tendon to heal back to the bone.

Dr. Justin Arne...:             Yeah, I thought that was one of the best points you made in the article. Talking about some of that displacements can occur with cyclic load and whip stitching an ACL and things like that. You're going to have some creep, which maybe is not as apparent whenever you're putting it in that bone tunnel. But as we all know, there's some risk being eccentric on the bone tunnel. So I think that's a great point that you made in your article. Certainly think it's useful for the people to read about that.

                                                So tell us a little bit about postoperatively, how you deal with these distal biceps. And do you think, one thing you mentioned since maybe there's some risk of displacement and you mentioned in your article, do you think we should go slower if we're doing an onlay technique? Or tell us how you treat these people post-op.

Dr. Eddie Chang:               Yeah. I've traditionally been more conservative on my rehab protocols, and I will put my patients in a splint for about a week before transitioning them into a hinged elbow brace. And over a period of six to eight weeks, they'll gradually regain full extension. There's been a few articles as well as multiple talks given about just placing the patient into the sling and begin active range of motion of the elbow. I just haven't been brave enough yet to do that. And if we're going back through onlay technique, I think that's something we probably need to be a little bit more careful of is to maybe not allow them to range their elbow too early in the post-operative period. So I'll probably continue to splint them post-operatively. And if there's data moving forward saying that you can begin early active range of motion of the elbow following onlay technique, I'll definitely consider switching.

Dr. Justin Arne...:             Yeah, that's a good point. One thing that a few different people that I've worked with, some people lock the elbow brace at, say 90 degrees or whatever, and some folks just limit the extension, but allow them to flex it. Do you have a preference or thought about that with your brace afterwards? Do you keep them locked in a certain degree and just come out for therapy or do you leave them, say 30 degrees shy of full extension and let them flex unlocked in the brace?

Dr. Eddie Chang:               Oh, that's a great point. I actually have them unlocked for full flexion and I'll have an extension block at about 45 degrees at the first week post-operatively. And I'll leave that for about the first week or so. And then after that unlock about 15 degrees every week until they get full extension by week six or so, and then after that they can get rid of the brace.

Dr. Justin Arne...:             That makes sense. And what are your thoughts about strengthening afterwards? Certainly with in orthopedics and there's some data with the distal biceps, doing some obviously very light strengthening a little earlier maybe let's this thing heal. Some people talk about, if you make it through the first six weeks that's the riskier part. I've still been, like you mentioned, a little bit gun-shy with strengthening, especially in this population. A lot of these are younger men that are big weightlifters. When do you let them start doing some strengthening?

Dr. Eddie Chang:               I usually let them start light strengthening, concentric only, about six weeks post-operatively under the guise of physical therapy. These patients, you're right. They're generally weightlifters or work in kind of more of a laborer type job. And so I worry that if we give them an inch, they'll go a mile and potentially, cause a re-rupture or re-injury early on. And so I try to be a little bit more conservative with these patients and definitely tell them not to do any type of eccentric contraction early on.

Dr. Justin Arne...:             Yeah, I think that's a good point. Certainly there's, like you mentioned, more aggressive and less aggressive means to this, but I think it's interesting to talk about. A lot of very thoughtful people have done some good studies about post-op, like you mentioned. Someone at UPMC here that probably a lot of listeners are familiar with is Mark Baratz, a hand surgeon. He talks a little bit about non-dominant folks with a distal biceps rupture not needing repair, or obviously if people are old and, sorry, less active, maybe they don't need to all have biceps repairs distally. Tell us your approach. Are you fixing pretty much all non-dominant distal biceps, at least in younger and active people?

Dr. Eddie Chang:               Yeah. And Dr. Baratz did publish a good article in JBGS back in 2009, looking at the non-operative treatment of distal biceps ruptures, and showing that they can have an acceptable outcome, although they need to be counseled on reduced strength, especially in supination. So my approach to distal biceps ruptures really is kind of patient ... you look at each patient individually. And so if they're young and active, they're likely less, or sorry, they're less likely going to tolerate the 30% loss in supination strength. Or if they're a laborer, same idea. If they're a carpenter, they're not going to want to lose that strength, especially if they're handling the screwdriver, et cetera.

                                                And so for those patients, I'll be a little bit more aggressive. And honestly, the patients are going to be the ones asking to have that repair. Now, if the patient is a more sedentary individual in their later fifties, sixties, or seventies, non-dominant arm, not really that active, you just go over the data that Dr Baratz published and kind of let them come up with an informed decision to get. And oftentimes they'll probably end up having surgery, but I've treated a few successfully without, and on exam, you'll notice some modest supination loss in terms of strength, but otherwise they're doing okay.

Dr. Justin Arne...:             Yeah. That's a great point. I love your knowledge of literature. That's really helpful, I think for all of us to learn. So I think it's about time for us to wrap up. Do you have any final thoughts about this? Again, congratulations on a really successful and difficult study to put together, especially with multiple institutions. So you've done a lot of great studies and appreciate your time tonight.

Dr. Eddie Chang:               Oh, no. Yeah. And thanks again for having me. This was, again, a joint effort with multiple institutions and I want to thank all my coauthors again, for all their hard work on this. I think that this is the study really goes back to one of my mentors, Dr. [Foo's] idea of recreating and preserving the natural anatomy. And he talks about quite a bit in ACL reconstruction in terms of tunnel placement and putting it back where it belongs.

                                                And when I think about us creating sockets or troughs on the radial tuberosity and kind of lowering or reducing that moment arm, I just wonder, are we actually doing the right thing for this patient? And if onlay techniques previously in the past with suture anchors and unicortical buttons work as well, I think the next generation of all-suture anchors, which have the advantages of a button, but also have the advantage of not having any metallic interference for future imaging studies, hopefully potentially this could be the future, although we need to do more clinical studies and comparing this directly with the standard of care.

Dr. Justin Arne...:             Yeah, for sure. I think it's certainly nice not to have a metallic implant and worry about flipping a button and all those things. So appreciate your time. And thanks again. Dr. Chang's paper entitled Intramedullary Unicortical Button in All-Suture Anchors Provide Similar Maximum Strength for Onlay Distal Biceps Tendon Repair is in press in the Arthroscopy Journal and is currently available online at www.arthroscopyjournal.org. Thanks so much for joining us.

Speaker 3:                           The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association or the Arthroscopy Journal.