Hello, this is Gus Mazzocca, and we'll be talking about distal biceps tears, appreciating anatomy, biomechanics, and complications. My disclosures, both Arthrex and Restore3D, but have been mitigated through the Mass General Hospital Office of Interactions with Industry. So really today, we want to talk a little bit about the historic literature, define some of the surgically important anatomy and osteology, review some of the clinical indications, as well as non-operative treatment, and then evaluate our surgical technique and what we kind of use in our area. So really, 3% ruptures, men are a little bit more than women. This is really from an eccentric contraction. That's kind of, you know, very common, people moving refrigerators, grabbing things and having kind of an eccentric contraction causing a distal biceps rupture. In the world of the surgical history, really the single incision was the first reported in 1897. Then Boyden Anderson's two-incision repair was modified by Dr. Morey in 85. Suture anchors came in 95. Endobunt with breakband, interference screw, and then some combined techniques. So the applied microanatomy, the distal tendon is really subjected to tension as well as pressure and shearing forces. This is really a gliding tendon. There's really two distinct histological areas, the ulna and radial sides of this. Ulna really dominated by type 1 collagen and tenosites, whereas the radial side, type 2 collagen and fibrocartilage. Blood supply comes from the cubital artery and there is considered a hypovascular area of fibrocartilage at that transition zone. So pathogenesis ruptures, really there's three main types, both the vascular where we talked about that hypovascular area at the fibrocartilage zone, mechanical increased spursal size roughening of the tuberosity, some patients have larger tuberosities, and then mechanical repetitive stress failure against a ridge, kind of a bony excretions. And as we talked about eccentric muscle contraction, that provides the most force and that's when these things usually go, somewhere around middle age. So the tendon inserts on the ulnar side of the tuberosity. It's good to be aware of that. It does twist about 90 degrees before its insertion on the ulnar side, as you can see in this picture. There are two heads of the biceps, the long and the short head, which have two distinct muscle fiber groups. You can see on this slide to the left, number one, the muscle belly of the long head of the biceps, number two, the belly of the short head, and the distal biceps of the short head has been isolated here with that probe. So it inserts more distally on the radial tuberosity. Some of the anatomic textbooks will talk about the tendon inserting over an area of three centimeters, which is the entire radial tuberosity. This is actually not true. It's really a ribbon on the ulnar side, as you can see here. So it's long and thin on the ulnar side, which increases its ability to perform supination, which is really what it does. Like we say here, it's about 15 by two millimeters, 15 millimeters in length and two millimeters wide. There are various types of ridges that'll be seen. We've looked at that to see kind of in an osteological example, where we looked at large, medium, and small. There's also bifid and smooth, but we were not able to ever correlate who had more ruptures or not based on this. This is just a side-by-side view of the distal biceps tendon during supination and pronation, and you can see where it goes. So it is the main supinator of the arm, and that's when that muscle contracts. It's going to create supination based on the fact that it's really on the ulnar side of that radial tuberosity. When ruptures on physical exam, you can see what they call the Popeye deformity or the asymmetry, where the biceps goes more proximally. There's usually some significant ecchymosis, and then Dr. O'Driscoll talked about the hook test, where you can feel that distal biceps tendon with your finger, and when it's not there, then that's pretty specific for distal biceps rupture. Radiologically, generally, people are all over the place when it comes to whether you need an MRI. We'll always get radiographs, which are normal, but I always want to check to make sure there's no other abnormality seen there. MRI, I do use also for the same reason. There's also this FABS view, which is elbow flex, shoulder abducted, forearm supine, which as you can see in this picture, really gives you a good angle and good view of the distal biceps insertion on the ulnar side of that radial tuberosity. This is a video where I really like the axial T2-weighted image, and what you can do is you can kind of follow that tendon down where it goes to radial tuberosity and see how it has some high signal there. You can also look on the both sagittal and coronal images to try to see, but I really like the axial view where we come down and we follow that tendon right to the radial tuberosity where you'll see some high signal down there. You can see it here. Here's the tendon with my cursor, and as we cycle down, you can see where it goes. This is just an example where you can see the distal biceps tendon that's been torn and retracted, and a lot of times the radiology people that read these MRIs will talk about that retraction to give you a sense of where that's going to be. So indications and contraindications for surgery, indications, active patient, acute rupture, chronic tear with significant weakness, continued pain, weakness after non-operative treatment. A lot of people really, the operation is much easier if you do it acutely. There's usually a big hematoma. You can follow that track right down. It makes it a little easier. The longer you wait, a little bit more dissection has to happen. There are some relative contraindications where obviously active infection, pain disorder, significant health issues, and if the patient chooses it. So we did a look at this a while ago. Where we looked at people that chose non-operative treatment. So the first question we had was how do patients that choose non-operative treatment do after physical therapy? So all of these people here chose not to have surgery, all returned to work within seven days. There were no manual labors in this group. So we looked at their peak torque at the time of injury and after physical therapy. And you can see that there is really a less than a 10% difference after physical therapy when compared to the unaffected arm. Supination endurance measured at the time of injury and after physical therapy. You can see that there was a 22% difference with higher variability compared to the unaffected arm. So really it's not a loss of strength per se, as more as a loss of endurance and supination. So how do patients that choose non-operative fixation compare to those who had operative fixation? So we looked at this supination, pronation, flexion, and extension. And really there was no clinical or statistical difference between any of these groups. Torque generation following distal bicep ruptured compared with normal supination strength. You can see normal dominant in the blue, normal non-dominant in the red. Treated affected and treated unaffected. 6% difference between the dominant and non-dominant strength in normal people. That's the dominant versus non-operative arm. Then you can see a 25% difference between operative and normal. And then you can see a 16% difference between non-operative and normal. So really this is kind of what we wanted to show. Same thing here. No significant difference between operative and non-operative when it comes to peak torque. Elbow scores were also pretty consistent over this. And this is really with people that choose non-operative treatment. So it's not all comers, which is always confusing when people read this paper. So if people choose non-operative, this is what we tell them. So we also looked at activities of daily living with torque comparison and foot pounds. So here's your difference between your normal dominant arm and your normal non-dominant arm. Non-dominant, slightly less peak torque. Then we looked at operative and non-operative. And then we looked at various kind of activities of daily living, opening a jar, turning a doorknob, pouring coffee from a pot, and looked at those. So really most other activities fall below the loss experienced by non-operative treatment. So we're not advocating this treatment, but offering practical information for patients that choose it. So distal biceps rupture treated with PT or surgery associated with some pain and weakness. Double the difference found between the uninjured dominant and non-dominant. Weakness is more pronounced in association with endurance or activities that require more than 20 reps of supination. Able to do most activities of daily living without difficulty, golf, yard work, etc. So why are these patients different than other non-operative patients that reported in the past? We felt that really starting them longer, immediately into physical therapy, working on that, getting full range of motion, getting full strength, and having them checked to make sure there were no issues. And then our follow-up period was longer, 4.5 years compared to 15 months from Dr. Mori's article. So current surgical technique, there's a number of them. There's a single incision bone tunnel that you and Caputo talked about in 2003, where you make a tunnel and then put sutures through the bony bridge and then tie that in. There's suture anchor that Dr. Littner and Fisher talked about in 96, where you put suture anchors in and then just repair the tendon to the surface. There's a cortical button where Greg Bain did this with the endobutton, where that was on the dorsal surface of the radial tuberosity. And then an interference screw that was in 2003. So successful and similar clinical outcomes of single and double incision distal biceps repair. This has been a debate that is really based on surgeon preference, I think. So these are some articles that we took out from the literature showing double incision repair outcomes, all reproducible and successful clinical outcomes for the two incision, single incision outcomes, all of these papers, once again, reproducible and successful clinical outcomes, double incision complications, really some mild heterotopic ossification and transient lateral antebrachial cutaneous nerve injuries, and then single incision complications, mild heterotopic ossification and transient lateral antebrachial cutaneous nerve injuries. So really, the idea is that whatever you're comfortable with and can do a good job with is the right approach for you. So this is kind of our algorithm that we look at from a complete rupture, acute approximately three to four weeks, delayed three to 12 weeks, and then chronic roughly greater than 12 weeks. And the reason why we bring this up is because generally speaking, we use a cortical button and interference screw. However, if you have a very retracted tendon and you can't fix it, you can fix a distal biceps with the elbow flexed in 90 degrees. And at that time, if we choose that, it would just be with a cortical button. And if it's poor tissue, you can augment it with some dermal allograft to try to get you about two to three more centimeters, and sometimes that is enough. And then finally, in a chronic situation, we'll use an Achilles allograft or a semitendinosus allograft to try to reconstruct going through the muscle and then repairing that into the radial tuberosity. We looked at the clinical functional outcomes after operative and non-operative treatment of distal biceps tendon ruptures in a consecutive case series back in 2021. You can see here we had complete rupture, partial ruptures, operatively treated, non-operatively treated. And what we found was we had improved ASES scores, SANE and DASH. Also in this, where you can see your complete distal biceps tendon ruptures, non-operative versus partial distal biceps ruptures, non-operative compared to complete ruptures, operative and partial operative. You can see the error bars. There is variability, but we were able to get all with anatomic single incision approach. So, we also looked at the biomechanics of these four different ways. Interference screw, endobutton or cortical button, suture anchor, and bone tunnel. And what we found was the load to failure was significantly greater with the cortical button than in the other three types, suture anchor, interference screw, or bone tunnel. Those were significantly different. The key thing for us when we looked at this was in our cyclic loading. So this was 3,500 cycles, kind of reproducing what you would do for immediate range of motion before this had healed at about 12 weeks. And what we found was really the interference screw had the least amount of displacement compared to bone tunnel, cortical button, suture anchor. So this is why we combined them. So for us, acute repair, less than three to four weeks, partial biceps tear that has failed conservative management, we use a cortical button and interference screw. This is the way we started. We have room set up and prep and drape with an Esmark to exsanguinate. I will sterilely prep the hand so I can see it. We put IO band over that so we have all aspects of that. And this is just kind of how we set it up in our room. We'll have the mini C-arm come from the head so that I can really get x-rays if we need it. Three finger breaths from the intercubital fossa is where we make the incision. We make a horizontal incision because we think that has better cosmesis and less scar. If you're worried about where you are and don't trust this three finger breaths from the intercubital fossa, you can take a little mini C-arm image and see that you're going to be right there. Our approach, once we go down, we go through the soft tissue and try to get down. We keep the fascia intact at this point. We want to be very careful for the lateral antebrachial cutaneous nerve. When I can send patients, I'll always say that you're going to get a little numbness and tingling in the lateral aspect of your forearm. I tell them that we're going to see that nerve, that we're going to move it. And oftentimes when we move it, that causes a little bit of that neuropraxia that they may feel. And we warn them about that from the beginning. What we'll do at this point then is take an Army-Navy, lift that up, and I will dissect bluntly with my fingers to try to find the ruptured distal biceps tendon that is gone proximally. When I do this bluntly staying above the fascia, remember the biceps is the most anterior muscle. So I stay as anterior as I can right in that subcutaneous area. And that allows me to be safe because a lot of times these tendons will retract up under it to the side of it, especially if the lacertus fibrosus is also torn. We'll use an Army-Navy retractor and I'll use a headlight to try to see that. So this is just showing that we'll take, a lot of times there may be a pseudomembrane in cases of partial tear that you need to dissect out. And these are just some pictures of trying to dissect that out so you're aware. We'll debride the poor tissue and prepare the distal bicep tendon for suture application. A lot of times there's some poor tissue and you have to make a judgment at that point of how much you want to debride, what tissue looks good and what tissue doesn't, what's going to hold the suture well for you. We then place locking crack house stitches from distal to proximally about two and a half centimeters. And at that time, then we'll place, we use a number two non-absorbable collagen-coated and attach our cortical button to the very end of that. Then we use a second collagen-coated number two non-absorbable suture for the interference group. That'll go proximally and distally and I'll tie a knot at the end of that. And then we'll snap that. We now approach to the radial tuberosity through a prorated teres brachialis interval. We want to make sure that any permanent retractors that we ever use are going to be on the ulnar side as we want to take special care to protect the posterior interosseous nerve, which is coming on that radial side. So as we go down, we'll follow the hematoma and if it's not there, we'll follow our area down between that, oftentimes coming to the lesion Henry, which is a venous plexus. We'll try to protect that as much as we can, but if we have to, we'll bovie those veins. And if we need to, then we'll also tie them off. So we'll put a small baby Bennett on the ulnar side and then always on the radial side, we'll have an army-navy that'll be held, not permanent. Once we have that radial tuberosity well visualized, we'll then start to prepare that. One thing to remember is hypersupination at this point, the thenar eminence is exactly or maybe exactly is the wrong word, but it's very similar to the radial tuberosity. So the position of the thenar eminence can show you where your radial tuberosity is. And we try to hypersupinate through the forearm, not the hand or the wrist. We don't damage anything while they're under anesthesia so that we have great visualization of that radial tuberosity. But I like that thenar eminence trick so I can really get good visualization and we know. We'll then place a pin and confirm on mini C-arm, then we'll take our reamer for our proximal hold, and this will be for our interference screw that can be of various sizes depending on what system you're using. Once again, we'll hypersupinate the forearm to protect the posterior osseous nerve. With that pin, we'll be able to see the placement of the pin and where we are. In this x-ray to the right, it looks like we're a little proximal on that radial tuberosity, so we may elect to change that and go a little bit more distal before we ream. We'll irrigate tremendously at this point to try to remove all of that bone debris from the reaming. We'll ream in and not ream out so we don't expand the hole. And at that point, then we'll tap for our interference screw. Then we'll use a 3.2 millimeter drill and we're going to place that ulnarly once again to protect the posterior osseous nerve, which is on the radial side. So drilling both our first, which is our first tunnel for the interference screw, and then in a separate tunnel going more ulnarly, and that'll be the tunnel that we make for our cortical button. We'll then insert the cortical button into that tendon and then place a forceps or snap on the distal biceps. We can then flex the arm up and then we'll sink that tendon into that tunnel completely. We don't like to pull it with the sutures because sometimes that can abrade the sutures and there can be some friction there, so we'll flex, pronate if we need to, and then get that tendon really deep into that tunnel. We'll check that the button is deployed with a mini-serum at that time, not stuck in the extensor muscle. And then we tie that first knot with an arthroscopic knot pusher so that we go through the tunnel and tie it right at the very dorsal cortex. With our second suture, we'll place that one long suture through the cantilater portion of that interference screw, and then we'll put that on the radial side so that the tendon is then crushed onto the ulnar side, making that anatomic. I currently use a 7x10 peak interference screw placed on the radial side so that tendon is buried on the ulnar side. You can see the images here below and to the right. And then we'll confirm no issues such as fracture on the mini-c-arm. We'll pronate and supinate, flex and extend, making sure that everything is exactly anatomic, which is what we want. We'll then try to close that extensor and flexor muscle fascia with a 2-O-Vicryl to avoid hematoma formation. Then we use a 4-O-Monocryl, cross, running, and then stereostrips. We'll place patients in kind of this bulky dressing. We don't splint them because we want them to start doing range of motion immediately. We'll have them wear a sling for two to three days just for protection and wound stability. Then they can start active range of motion, extension, flexion, supination, and pronation. We do formal physical therapy only if they're unable to establish their own range of motion. We'll do heavy lifting only after 12 weeks. A lot of times now what I also do is have them go to occupational therapy and get placed in what we call a thermoplast splint, which is a 90-degree splint splinted with neutral rotation. That's only really to remind them when they're doing heavy activities not to really put a lot of stress on it. These are some 10-year follow-up x-rays. We can see some mild heterotopic ossification and a little bit of that remodeling of the radial tuberosity. If you get into trouble and you find that you can't get the distal biceps down to the radial tuberosity, you thought you could and you can't for whatever reason, and you can't fix it in 90 degrees of flexion, there is this procedure that was talked about in 2017 where you can use dermal allograft augmentation. And what we do is we'll use this 2-millimeter acellular humerin allograft. We'll place that into a trapezoidal shape and create what we call a burrito type of mechanism where we'll wrap that around a large part of the distal biceps stump and then get you another 2-3 centimeters of extra tendon length to try to execute your procedure. The reason why we like that is because that's an off-the-shelf for us right now. Any type of allograft would do, but that is one of those cases where you don't think you're going to get into trouble and all of a sudden you notice that you're about 2-3 centimeters short and that's been a kind of a great bailout for us. Achilles tendon allograft augmentation, this is really a retracted issue, greater than 12 weeks, scarred in, they still have pain, they're unhappy, weakness to supination. This is a much bigger operation. You can see we'll start with our horizontal incision, but then go up through to try to get exposure to the biceps muscle. What we'll do is we'll take an Achilles allograft first with both a cortical point and interference group on the radial side and we'll fix that into the radial tuberosity first. Then what we'll do is we'll tunnel that up through to the biceps muscle and at that time we'll then pull the biceps muscle down, having the patient arm in some flexion so that we can get it as high up and as tight as possible. Another procedure that we've also gone to, as opposed to just putting the Achilles over the muscle, is using a semitendinosus or hamstring allograft and then doing a pulvative imbrication through the muscle and then pulling that down. We do the same closure, same type of starting early range of motion for our closure post-op. Like we said, we start active assisted flexion, passive extension, we start supination or pronation right away. They can use their hand and wrist for anything they need. We just we hold on any significant weight bearing for 12 weeks. Of the 480 initial studies, 40 papers were satisfied full-text inclusion criteria. Patients, employers may be given a range between three and four months with variations depending on job demands for your workers complications. Complications, really nerve palsy, most common is lateral antebrachial cutaneous nerve. We've really been able to eliminate the real concern of the posterior interosseous nerve injury because all of our techniques now involve going mostly on the ulnar side where it's blind for us. Post-operative stiffness, we've been able to significantly decrease because we start range of motion immediately. They always do get some amount of heterotopic ossification a little bit. We take x-rays usually at the six-week visit and then at one year just to keep an eye on that. We have not had any radial tuberosity fractures and one re-rupture. So take-home points, the surgically significant anatomy, remember this is about a 14 in length, two millimeter in width attaching it on the ulnar side of the tuberosity. We believe that the combined interference screw and cortical button is the strongest with the least amount of displacement. You want to place that interference screw on the radial side forcing the tendon to the ulnar insertion which is anatomic and we start early range of motion decreasing our stiffness and heterotopic ossification. I want to thank you all for this opportunity and good luck.

distal biceps tears

surgical techniques

biomechanics

non-operative treatments

MRI imaging

post-operative exercises

tendon augmentation