The latest advances in surgical and non-surgical treatment of Achilles tendon injuries.
In this episode, we dive into Achilles tendon tears, covering everything from anatomy and causes to the latest surgical repair techniques and rehab strategies. Hear from experts about the journey from injury to recovery and the advances in surgical techniques used to address these common injuries.
Narrator: SiriusXM presents an NYU Langone Orthopedics podcast. Orthopedics is just very important to the population in this country. Its ability to restore patient function. Problems related to cartilage, to someone who has more advanced forms of arthritis. Getting people back to their activities and the things that they like to do. Featuring NYU's experts in the field of orthopedics trying to figure out that problem before it even is a problem. Problems with solutions. Well beyond physical therapy, to conservative pain management, to surgery. The best medical minds now come together. Applying all of our minds to solve these problems. We're here to get people feeling better so they can get back to their lives. And that's really what we try and accomplish. These are the Bone Whisperers.
Doctor Guillem Lomas: Hi, this is Doctor Guillem Lomas from the Division of Sports Medicine in the Department of Orthopedic Surgery here at NYU. And we are talking today with the one and only Doctor John Kennedy, a Professor of Orthopedic Surgery here at NYU, Chief of the Foot and Ankle Division, and also Co Director of Orthobiologics at NYU. And we're going to be talking about the Achilles tendon, specifically, what to do if it's torn. Doctor Kennedy, welcome to the show.
Doctor John Kennedy: Thank you, Guillem. It's a great, uh, pleasure and honor to be here.
Doctor Guillem Lomas: Yeah, well, this is a great topic because I have to say, it seems like in the summer months, you definitely see this spate. There's almost an epidemic of Achilles injuries. And there's a lot of information out there, and I think for a lot of patients, it can be somewhat confusing. Do I fix it? Do I not? What do I do with it? So I'm looking forward to discussing those intricacies with you.
Doctor John Kennedy: Yeah, it's something we get asked all the time, and you're absolutely right. In the summer months patients are much more active than they would be typically in the winter months. And many of us who believe we're still 21 and are running around and have long gone beyond our sell by date are still trying to do the things we did at 21. And of course, that puts the Achilles at particular risk. As you know, the Achilles is this big, strong tendon at the back of your calf. It links the calf to your heel bone, and it's really used to propel you forward. And the times that it's most at risk are, incidentally, it's interesting, it's really when you decelerate. So if you're playing squash and you have to suddenly stop and turn, if you're playing basketball, you stop and turn, or tennis or these type of sports. So that's really what the major sports involved in Achilles. But of course, you're going to have a running. Running down a hill is commonly one of the causes. And patients often come in and they say, you know, I felt somebody whack me in the back of the ankle with a tennis racket or whatever it is. And they turn around and of course, there's nobody there, uh, because the enormous energy required to pull it apart and it really is explosive. And that's one of the criteria we use to decide whether or not we're going to be fixing this with a surgical intervention or whether we should treat it in a conservative fashion.
Doctor Guillem Lomas: So that's excellent. A good primer. You know, I was going to say, most of us have a sense of what the Achilles tendon is. Maybe we remember it from our history course and, you know, the Trojan War, he was some guy involved there. But, you know, historically, kind of a fascinating tendon, a fascinating body structure, and, you know, even the fact that it was singled out in Greek mythology, historically, it seems like it was the type of injury that would render someone very incapacitated, right? So classically, you cut someone's Achilles tendon, well, that's over. They're probably never going to walk again. Is there any historical truth to that? Or is it maybe just something that is apocryphal and kind of passed down through time? But people did heal Achilles in the past.
Doctor John Kennedy: It is a great question, and it is of historical interest that the Achilles was considered to be one of the most important tendons, because once it was transected, the likelihood of that person getting back to any sort of active lifestyle - in those days, it was either fighting or being out in the farms and doing what you needed to do - was limited because you simply don't have that explosive push off or the ability to run or be useful in many ways. And that prompted surgeons to look at this as something that needed to be fixed. And the outcomes of fixation of an Achilles are very, very good. Most people get back to their previous level of activity. But when you look at the data, most recently, you can see that there's now a trend, that there are some people who are advocating that it doesn't always have to be fixed. There are a certain group of patients in which, in fact, fixation may be the wrong thing to do. And that the difficulty comes, of course, when the patient comes to your office to figure out what's the best course for that particular patient. So we use the criteria based on what their demands for their activity should be or what they would like it to be. So if it's a professional athlete, I think our algorithm at NYU is that those patients should typically be treated with a surgical correction. And there's various different types of surgery, and we can go into that a little bit later. But surgery really means joining the two ends of the torn tendon together again and allowing that time to heal with or without the use of a biological adjunct, and then getting into prolonged rehab to get back to previous level of sport. But if the patient isn't particularly active, then you're increasing the risk of any surgical complication by bringing that patient to an operating room. And now we know that many patients can have a functional Achilles. They can get around and do the things they want to do for activities of daily living. So that's really the decision as to whether we move forward with surgery or not is really based on the patient and what their demands are. Neither approach is wrong, and both are now acceptable.
Doctor Guillem Lomas: Well, I love the idea of kind of the bespoke approach. You know, every patient is going to have a different set of demands and weighing risks and benefits of surgery. Let's talk about that non operative patient. Someone walks into your office, somebody who you would deem potentially a good candidate for non operative treatment. And then, I think for our audience, too, just give us a sense of what that non operative treatment is. So sometimes a lot of people assume, well, non operative treatment means do nothing. Is that the case, or are we actively still doing something? Are we giving treatment recommendations to those patients who don't need surgery?
Doctor John Kennedy: Yeah, I think that's a great question, Gilliam. What we now know, and which we didn't know previously, when we used to put patients into these big plaster casts for three months and so forth, is, of course, the tendon would heal, but it would heal with this very thickened scar tissue, which wasn't elastic like the rest of the tendon. And, of course, that really consigned that patient to very little - it didn't have the same push off strength and so forth. But now, with advanced physical therapy, we know that if you can actually get the patient being weight-bearing fairly early on in their recovery, and that's within two weeks, it will actually stimulate the tendon cells to start to line up. And that's very important in terms of elasticity within the tendon. So we now know that early weight-bearing, limited range of motion, and advancing slowly over a period of two to three months will allow that patient to get back to a pretty good functional recovery. The old data that they were going to be at least 10 to 20% weaker, and that with a 10 to 20% likelihood of re rupture - has been challenged now. And I think that with the use of orthobiologics, where we can inject various biologic agents into the healing tendon to improve the biological milieu there, combined with newer and advanced physical therapy, rehab programs, have really reduced that. It's still not the same in terms of re-rupture rates and endurance and strength as a surgically repaired tendon, but it's getting pretty close.
Doctor Guillem Lomas: Yeah. And you mentioned again the different demands on the tendon. Those patients who are really redlining, stressing that tendon, you know, that may not be acceptable for them to have even a, uh, small, single digit percentage increase in re-rupture risk.
Doctor John Kennedy: Exactly. So if you're in the NFL, if you're in the NBA, you're not going to sit around for three months to allow this to heal, because not only do you get osteopenia, you get sarcopenia, you get deconditioning of all the other joints and muscles and soft tissues and so forth in the body. So for a competitive athlete, or for any type of athlete, really, we advocate surgical repair on those, unless there are contraindications. So for a surgical repair, there used to be the old technique. We'd make a big, big incision, and then we joined the ends together with this very, very strong suture material. And then again, we immobilize the patient in these big casts, allowing the wound to heal, allowing the tendon to heal. And, of course, when you took the patient out of the cast at eight weeks, they couldn't move anything. And so, again, with advanced physical therapy regimens and rehab protocols, we now know that, again, even with a repair tendon, you must start moving them early. And that, again, is if you think of a tendon almost like a rope. If you imagine once you tear the tendon, it's like two mop ends that you're trying to join together, very disorganized, random organization of the strands of that rope. But as soon as you start to put very gradual stress through that, through range of motion and limited weight bearing, those strands start to align up. And once you start to get that better alignment, you get this better modulus of elasticity. In other words, it represents much closer to the normal tendon than would be if it was just allowed to sit there and heal for months and months of inactivity.
Doctor Guillem Lomas: You mentioned orthobiologics - injections to be done potentially, whether or not you're repairing or treating the, uh, tendon tear nonoperatively. You're Co Director of the Orthobiologics Division here at NYU. You're a pioneer in the field. You've done a lot of tremendous work pushing research. When do you typically inject patients with, whether it's PRP or stem cells? What are your thoughts about timing, and do you do it in both the non operative and operative settings?
Doctor John Kennedy: We do. And the reason we do is oftentimes the pathology of a torn tendon is not just related to the mechanics for that sudden mechanical deceleration. It's often related to poor biology in the area. We know that the tendon typically tears about a hand's breadth above the heel in this, what's known as a watershed area, has a particularly poor blood supply. So if all we did was just repair the tendon, well, that poor blood supply still remains. And of course, it allows the tendon to heal, but slowly, and it then predisposes the tendon to re rupture and all sorts of other problems. So if you can improve the biological milieu there, whether it be through non surgical intervention or surgical intervention, then that's a good thing. The problem with using biologics is oftentimes when you have a hammer, everything looks like a nail, and then you start to use it inadvertently. So what we have to do is we have to look at the basic science, and then we have to follow that up with good clinical science. So when you look at the basic science of when we add a biologic, and in this case, you talked about PRP, which is a blood product where we take platelets, and then we talk about concentrated bone marrow aspirate provided stem cells. When you add both of those individually or combined, it actually upregulates a gene within the tendon in a very sophisticated way. It increases tenocytes, and tenocytes are the cells that are responsible for making tendons, and it upregulates those. So it starts laying down better quality material than just scar tissue alone. So that, for us, was very exciting. Then we started to look at it in terms of clinical outcomes. Did it really affect important things for an athlete or return to play? Could you get an athlete back on the pitch or on the boards quicker if you use a biologic by comparison to those that didn't? And on average, you get them back at about nine weeks sooner if you use a biologic. So, for any team or any player involved in a team, that's very, very important. Now, downstream from that, the outcomes are roughly the same. So, in terms of the strength, likelihood of re-rupture, and so forth, all even out over a year. But if you're looking to get somebody, a player back sooner, then we certainly would advocate that.
Doctor Guillem Lomas: And is that something we do, multiple injections, timing wise, a couple of weeks after that initial injury insult? Or is there an algorithm you use or it just depends on the situation?
Doctor John Kennedy: Yeah, so there are various algorithms that are used. The one that we use in NYU is we give a single injection. We've looked at giving multiple injections in an animal model, and it really didn't show that there was any great difference. So we give a single injection. And again, the timing of the injection is important, and whether you use a white cell within the injection is important as well. So we can get into the weeds a little bit about that. But the most important thing is to remember this is a biologically challenged area. That's why it tore in the first place. So to improve the biology is important, and that's why we believe in it. So you can see that both in those treated with a conservative, non operative treatment versus those treated with operative treatment, both groups did better in terms of return to sport, return to normal activity when treated with PRP or with CBMA.
Doctor Guillem Lomas: Right. I want to talk about three specific injury patterns and get your thoughts on them. These days, patients will get the radiology report directly from the radiologist, sometimes with even a little summary from the radiologist. They come into the office, they're like, well, I know my injury already. What are you going to do about it? The first one is the amount of displacement of the tendon ends. So a lot of retraction, a patient will come and say, I have a six centimeter retracted tear. Does that factor into your decision to repair or not? Is there a certain amount of retraction, meaning separation of the two tendon ends, that for you, warrants surgical intervention?
Doctor John Kennedy: Yeah, there really is. And it was our concern when we started reading some very elegant studies that came out of Canada and other areas about the conservative treatment being an equivalence or close to equivalence of surgical treatment, there was one area that wasn't explored in terms of doing an ultrasound and looking to see how far had the tendon pulled apart. And then some studies started to come out to show that if it was pulled apart, even more than 5 millimeters, likelihood of success of conservative treatment was less. And so if you imagine this is an enormously powerful tendon, enormously powerful muscle. So it's explosive. When this happens, as we alluded to earlier, it's almost like an explosion, like a gunshot at the back. So it's very rare that you find the tendon has retracted just that little bit. So for our algorithm, really, if it's greater than 2 centimeter retraction, we would consider non or conservative treatment on that, unless there are extenuating circumstances, we can go into those in greater detail. But typically, that's the most important thing to consider - those tenocytes would have to grow over that two centimeter gap. And even if they did, the most important thing for getting your normal strength back is what's known as the length tension ratio. So if this tendon is elongated by 2 cm, it's very difficult for you to get that push-off strength that's required. And for us, that's why oftentimes surgical management is preferred, because we can measure that and compare it to the other side. So if you go to the operating room with an Achilles tendon tear, we'll prep out both sides and we look to see, as you're lying there, we'll see what your tendon looks like on the other side. And when we're repairing it, we'll compare it always to that length tension ratio, so we get it almost equivalent to the other side. And that means the likelihood of you having that push off power is much higher than if we were to treat it in a conservative fashion.
Doctor Guillem Lomas: Yeah, and I agree with you. I mean, this is one of those instances where the research, like you said, challenging the tenant that we needed to operate on every Achilles - that was helpful, but it was missing that nuance of - and there were a couple of other features, other characteristics - but that nuance of missing the amount of retraction is something that I think we're getting more information on. But makes a lot of sense when you think about that length tension relationship.
Doctor John Kennedy: Yeah.
Doctor Guillem Lomas: The other case I want to talk about - proximal Achilles tears. And what I mean by that is patients will come in and the radiologist will read something like a tear at the musculotendinous junction. So, right where the Achilles tendon meets the muscle, where there's fascia. That area is a little thinner. How do you treat those patients? Do you tend to treat those more non operatively? Do you also rely on the other characteristics, like retraction? How do you manage those?
Doctor John Kennedy: You do. They're a little bit more challenging in terms of any surgical intervention there. You've got to be careful of it. There's some nerves we have to be careful of around there. The sural nerve, which is really a sensory nerve, but nonetheless doesn't like to be interfered with. So you have to be careful surgically, but mostly because when you join two tendon pieces together, you have something to put a suture through. When it's at the myotendinous junction, it's much more difficult to do so. So you're trying to get it into a fascia, which is much thinner. It's like the covering of the tendon. It's much thinner. It's much more difficult to get the length tension ratio just perfect in that regard. So it does require a slightly different surgical skill set. In terms of conservative treatment, it's the same. The same protocol as you would - there's slightly better blood supply there, so we don't have to worry too much about biologics in that particular instance. But, yeah, they are different. They're different pathologies and slightly different surgical interventions, but conservative is roughly the same.
Doctor Guillem Lomas: The third case I want to talk about is the opposite end of the spectrum, tears off of the bone. So, as you mentioned initially, the Achilles connects the calf muscles to the heel bone, the calcaneus. How do you treat those tears? Do those always require surgery when that tendon is off the bone?
Doctor John Kennedy: Yeah, and these are difficult to treat because it's hard to treat those in a conservative fashion, because the likelihood of them again getting back to the length tension ratio is limited. Oftentimes, in fact, not only will they pull off the bone, but sometimes you'll see them that they actually have pulled some of the bone with them as well. And those can be not just functionally, but cosmetically disturbing to patients. So we go in and we fix those, oftentimes with screws. But for those who are truly pulled a sleeve off the back of the heel or the calcar tuber, as it's known, and we'll go in and operate on those. We sometimes have to put tiny little suture anchors into the bone, and then we'll reattach it. But you have to always go back to, why did this happen? And if all I'm going to do is repair it, maybe I've left the original cause of the problem still there. And there's often times this little bump of bone there. Patients often are born with it or can develop over time, known, um, as a Haglund's deformity or a Bauer’s Bump. I think you would know it as a Bauer’s Bump for a great skater. So I think that when you have these Bauer’s Bumps or little exostosis at the back, that often causes an attritional injury. And we often say that the tendon gets caught between the rock and the hard place, the rock being the bone, the hard place being the counter of the shoe, the back. And over time, that causes attritional degeneration of the tendon. And then it simply just pulls asunder. So, for those cases, we take some of the bone away, and then again, we have to get that length tension ratio very carefully because we've taken some of the bone away, and we need to lengthen the tendon a little bit to put that back on to get your spring back in your step.
Doctor Guillem Lomas: We've discussed operative, non operative indications. Let's assume we have decided to indicate a patient for surgery. A lot of patients will have read there's information out there about minimally invasive options. And we discussed how, traditionally, you'd make an incision, sew both ends, tie the sutures to themselves, and voila, there's your repair. How have we evolved? Where are we at in terms of different techniques to repair the Achilles that patients may have read about?
Doctor John Kennedy: Well, that's great. Again, with all orthopedics, we're evolving all the time, and that's the great thing. My old boss used to say, if you're doing the operation that I taught you how to do in ten years, you're doing the wrong operation, because we constantly have to be evolving and getting better at what we do to get better outcomes for our patients. So, in the old days, as I said, a traditional thing was to make an incision that could be four or five inches long to find the two ends and approximate them and bring them together. The complications with that is, of course, the bigger the incision, you had to protect it, particularly in an area that had a poor blood supply. So we used to get wound complications from that. Then probably 20 years ago in America and in Switzerland, people started to look at, well, can I do this percutaneously? Percutaneously just means small incisions, and that we can bring the two ends together without being this big extensile approach. And the indications were that we could, but the problem is that we started getting damage to this sural nerve, the nerve we talked about a little bit earlier on, and it lies just on the outside of the Achilles, about 3 or 4 mm away. And it's responsible for all the sensation on the outside of your foot. So, of course, if it gets a needle through it, it's not particularly happy, or if it gets a suture wrapped around it, it's not happy. So there's been an evolution in the percutaneous methods over the last ten to 20 years, where it is now much more effective. So we do many of these now through percutaneous methods. Again, when the distance between the two ends is not beyond 3 or 4 cm. Beyond that, where we have to find the two areas and bring them together, we have to do a slightly more extensile approach, but again, not going back to the way that it was 20 years ago, where we did these large incisions with risk to wound complications. The recovery time is far quicker, of course, as well now, because you don't have these big wounds, so you can get patients moving very quickly. We're not waiting for the skin to heal in these large incisions. So we're getting patients more moving almost, uh, right away. We usually let them relax the wound for a couple of days and then we start getting early motion in a cam boot almost immediately. And again, the reason for that is we go back to the tendon. If you let the tendon heal, think of it almost like an elastic or rubber band. If you're going to let it heal, if you cut a rubber band and stick it together with superglue, within a physiological amount of stretching, it'll always be fine. But when you stretch that beyond its physiological limit, the weakest link is always where you've glued it together. And it's the same thing with a tendon that heals in with scar tissue. It will always be weak, that scar tissue. But with early motion that scar tissue is limited. And we get different types of collagen there. The collagen, which is the building block of a tendon, is replaced with more what's known as collagen type one - which is very similar to normal collagen - than collagen type three, which is much more like scar tissue and doesn't have that same elasticity in there.
Doctor Guillem Lomas: Yeah, absolutely. Well, I'm going to ask for a friend here. Take your patient mid forties, but they're concerned about potentially tearing their Achilles. Prevention. I mean, you and I think are of the same ilk - we'd love to be out of a job because there were no injuries, although I don't know these days with inflation, maybe still have a little work to do. But tell me a little bit about any prevention strategy. Say somebody in their mid forties maybe that most common, the highest risk demographic to be injured, forties, fifties, sixties. Can people do anything to prevent or to mitigate the risk of actually tearing their Achilles.
Doctor John Kennedy: Yeah, you can. And I think that that point was underscored at NYU, one of our great residents, Andrew, produced a very nice paper looking at NFL injuries, uh, when COVID was here, and looking at the likelihood of developing an injury in that cohort of patients after the COVID shutdown by comparison to before. And what he found, I believe you're involved in this paper also, to show that patients or players were far more likely to have an Achilles injury after that period of relative deconditioning. And that was reflected not just in the NFL, but in the general population also. So that really led to show that it was important to maintain conditioning. So the tendon, just like anything, if it's not used, it will become deconditioned. And so the muscle tendon ratio, all of that, is very important to maintain conditioning. And so for those of us who are in the twilight years of our sporting careers, it is important to go to the gym and don't just go in and start doing Achilles stretches right away. And just go in and do it gradually. The body responds to gradual increments in stress and pressure put through it. So if you haven't been exercising for a period of time, to go out and just start doing box jumps is probably not the smart thing to do. So gradual return to normal conditioning is the way to do this. So that's how we prevent these injuries. Big studies done in Australia, particularly looking at these injuries in basketball and other sports, and again, what they've shown is that, again, conditioning is key to this.
Doctor Guillem Lomas: Doctor John Kennedy, on that note, if there ever was someone to discuss the nuances, the ins and outs of repairing an Achilles tendon, it is you. Thank you so much. Really good information.
Doctor John Kennedy: Thank you so much for having me.
Narrator: The Bone Whisperers is a co production of NYU Langone Health and SiriusXM. The podcast is produced by Scott Uhing. Sound design by Sam Doyle. SiriusXM's executive producer is Beth Ameen, and senior operations manager is Emily Anton. Narration and additional sound design by Michael Luce. Don't miss a single episode of the Bone Whisperers and subscribe for free wherever you listen to podcasts. To hear more from the world-renowned doctors at NYU Langone Health, tune in to Doctor Radio on SiriusXM on channel 110 or listen anytime on the SiriusXM app. For the Bone Whisperers podcast, I'm Michael Luce. Join us next time for the latest advances in orthopedics on the Bone Whisperers.