Dr. Chris Tucker:

Welcome to the Arthroscopy Journal podcast. I'm Dr. Chris Tucker from the Walter Reed National Military Medical Center and founding editor of the podcast. Today, we are discussing blood flow restriction therapy for post-operative thigh muscle atrophy. I'm honored to be joined today by Dr. Frank Noyes, an internationally recognized leader in sports medicine and knee surgery. The CEO of the Cincinnati SportsMedicine and Orthopaedic Center, President of the Noyes Knee Institute and Emeritus Professor of Orthopaedic Surgery at the University of Cincinnati. Dr. Noyes was the lead author on the recent article titled, Blood Flow Restriction Training Can Improve Peak Torque Strength in Chronic Atrophic Postoperative Quadriceps and Hamstrings Muscles, which was published in the September 2021 issue of the Arthroscopy Journal. His co-authors include Sue Barber-Westin and Lindsey Sipes. Dr. Noyes, congratulations on your work and welcome to the podcast.

Dr. Frank Noyes:

Well, Dr. Tucker, thank you very much. It's my honor to be here and I really enjoy talking about blood flow restrictions. So thank you for the opportunity to discuss this article.

Dr. Chris Tucker:

Well, I always enjoy discussing postoperative physical therapy, especially newer developments that can augment existing programs and enhance patients recovery. So you can imagine my excitement in reading your article and also having this opportunity to discuss the topic with you. So let's jump right in. Can you give our listeners some background on your interest in blood flow restriction therapy and what led to the development of the idea for this particular study?

Dr. Frank Noyes:

That's a very interesting question. I think as an orthopaedic surgeon, we have wrestled for 20, 30 years on what to do with our patient that has that chronic atrophy, that's not responding to traditional therapy. And that actually represents 10 to 20% of our patients that we have. And we came across an article by [Helden 00:01:55] seven active duty soldiers that I know that you are aware of. It was actually published in the journal of Special Ops and it was not published in a standard orthopaedic journal. And this was brought to our attention. It was published in 2015, and in 2016, this was brought to our attention. It was very interesting because in these seven active duty soldiers that were injured in war time, they had deficits of 13 to 38% in their peak muscle torque. And he took them through only six sessions and he actually reversed, not reversed, but had very significant responses to blood flow restriction therapy.

Dr. Frank Noyes:

And so, that led to our first systematic review that is referenced in this article. And that was published in 2018 in Sports Health. And to just give you 30 seconds of that, we looked at over 500 studies. Blood flow restriction therapy is not new. And we looked at 500 studies in the literature, but we were only able to bring it down to about nine studies that dealt with a knee joint, about 165 patients, and of that group. We only had about seven studies, very small population that said that number one, it was safe, number two, it probably was helpful, but there were so many variables on how the tourniquet was used, that you really couldn't come to conclusions. And so, that's how we initiated this study, which we started in 2017.

Dr. Chris Tucker:

That's a fascinating background. I always enjoy talking with authors to get that behind the scenes info. And on a side note for our listeners, if you're not aware Dr. Noyes, is actually an Air Force medical officer veteran. And I appreciate that and want to take the time just to acknowledge your service and thank you for that as well Dr. Noyes.

Dr. Frank Noyes:

Well, thank you and acknowledge your service, certainly.

Dr. Chris Tucker:

All right. So back to the topic at hand, I'm hoping you could explain for us the principles of blood flow restriction therapy itself and how this therapy came about.

Dr. Frank Noyes:

So if you look at the physiology, and we referenced many articles on the physiology and it actually gets a little bit complex. And we talk about metabolic stress, which we certainly have because we are exercising, but we're restricting in part the blood flow to that muscle. So that's producing anoxia and there's some very dramatic changes that you might expect would occur in the muscle.

Dr. Frank Noyes:

The buildup of lactic acid becomes more acidic, cortisone levels rise, nitric oxide levels change, but we really do not know under those circumstances, what is the signal? It's probably at a cellular level where that signal for RNA that is now the stimulus to produce increased fast twitch fibers and to produce muscle hypertrophy. And in those studies to produce an actual increase in cross-sectional area. So what we can say is that metabolic stress, lactic acid, anoxia is all a positive stimulus to increase muscle strength that we could measure by our peak muscle torque as in this study.

Dr. Chris Tucker:

That's fascinating. I enjoy hearing the physiology behind some clinical work that really is rooted in bench research knowledge. You are a world renowned knee surgeon. Why do you think this therapy technique in particular lends itself so well to the postoperative rehab of knee surgery patients?

Dr. Frank Noyes:

So we're going to look at two patient groups. The first patient group is just, if you mentioned the postoperative after surgery, and then the second patient group is the patient group that is not responding and has that chronic atrophy and you've done on everything that you can. And that is the study population that I'm going to drill down in a few minutes. But look at the advantage you have, you are exercising at one third of your maximal resistance. One third of your maximal resistance is the low load that you're going to use rather than high load. And we all know the literature is very complete that you have to exercise at 60 to 70% of one rep max to increase muscle strength. That's a tremendous force. And very simply we can't apply that load, that high load after surgery. We have a knee that has pain, has swelling limitation, range of motion, and they're just sitting there and getting more and more atrophy.

Dr. Frank Noyes:

We can use electrical muscle stimulation. We use isometrics. We do everything that we can, but after surgery, we are in a very significant tissue state for at least 12 weeks. So the question is, can a low load program with a tourniquet reverse that, and can we prevent that serious atrophy? And I'm going to answer the question. Yes it can, not in every study, but there's building evidence that does have a very positive influence. And I'll come back in a few minutes of how we use that in our clinic. And I will say that our clinic and many other clinics have now made that a standard of care to use BFR after surgery. The question we asked in this study is, now, will that work on a patient that has chronic atrophy, where there are not responding to anything that we do? And that's a more difficult question because here we're taking a muscle that has demonstrated atrophy and weakness, and can we reverse when they haven't responded to traditional therapy? And that's the one that I can give you a little bit more data on.

Dr. Chris Tucker:

Fascinating. I can't wait to get into that. So let's not beat around the bush and let's jump right into it. I think we all have a good grasp on the general principles that you very nicely covered for us. So let's talk about the specifics of your article. As you said, you investigated the effects of BFR on the recovery of postoperative, but chronic quadriceps and hamstring muscle atrophy. How did you go about conducting your study? And then please speak to your key findings.

Dr. Frank Noyes:

So again, it was very interesting that two thirds of these patients were my own patients and with Tim Heckman. And we think we have a excellent therapy group. We certainly have all the modern principles. So we started to enroll patients in 2017 through 2019. And this was a group that had, had five months of therapy over 20 visits. There were my total knees, a group of seven or eight total knees, about seven or eight ACLS. I had an osteotomy in there. I had meniscus repair. I have arthrofibrosis, that's very important. And you literally watch these patients in front of you get more and more atrophy. And if you measure their isokinetics, they're getting weaker and weaker and they're not responding. And that chronic muscle atrophy is the group that we enrolled. They had at least 43% deficit as a mean in their quad and their ham.

Dr. Frank Noyes:

They had to have greater than 20% deficit, but someone up to 78 per 8% deficit in their peak isokinetics, quadriceps and hamstring peak torque. That's a major group of people that are in trouble. And I will tell you, we call this a bailout. We did the BFR, the standard session that people use, 30 repetitions, keep the tourniquet on, do your one rep max calculations, 30% resistance, and then you do your 30 reps rest one minute, 15 reps, 15 reps, 15 reps. So it's called the 30, 15, 15, 15, and that's no one knows the right schedule, but that's the schedule that most people have used. So we adopted what is usually used. And then we went through four exercises that are actually fairly simple. Leg extension, a mini squat exercise, a leg press, and a hamstring, and just four exercises.

Dr. Frank Noyes:

It takes about 45 minutes to really take them through. You leave the tourniquet on, and you have the tourniquet at about 60 to 80% of occlusion pressure. And they have to reach a level of about a seven with 10 being the maximum pain, have to reach about a seven. So they're doing those exercises and it's somewhat painful for them to be able to do that. And so what were the results of that? Well, it actually exceeded our expectations. We had 86% or greater than a 20% increase. 20% increase in peak muscle toque is a big number. And we had up to 80%, both quad and ham that reached those high levels. About 10 to 20% did not. And so, it's not going to be 100%, but about 80% had these very significant gains, 20%, 30%, and even up to 40% and peak measured quad torque and hamstring torque.

Dr. Frank Noyes:

And I will tell you that it starts to work at three weeks. At three weeks it's nine sessions, Monday, Wednesday, Friday, but you really need six weeks, 18 sessions. And I will tell you, that's a real commitment of the patient and your therapy staff. And we'll get into that. But I will tell you as the surgeon, these are patients that we rescued. We literally rescued them with PFRT, Dr. Tucker. So we were actually surprised by the response to our PFRT and our patients.

Dr. Chris Tucker:

Extremely impressive. I think you and your staff and your therapist should certainly be commended for that effort in those results. I'm interested again, to talk more about the challenges associated with that, as you alluded to in a few questions, but first I wanted to know if there was anything particularly unexpected or surprising that came about during your work on this project that you wanted to share for us.

Dr. Frank Noyes:

Well, of positive and negative. The negative is that when you tell this that you're going to do this with a patient, you have to say, "You're used to using a blood pressure cuff, and all we're going to do is to just keep it on and we're going to keep it on for about five minutes and it's going to produce some pain." And so the negative aspect is about 15% of the patients say, "I don't want to do this and I'm doing this for 45 minutes." They're there in the clinic for 45 minutes, but the tourniquets only up about five minutes.

Dr. Frank Noyes:

And so, there will be a dropout rate where they say, "I don't think I want to participate in it." The positive aspect, we've had patients that would literally have a smile on their face while they're doing it. And they would say, that's the first time in five months that I got a muscle burn and I'm going to repeat that, they would see their leg turned a little bit reddish, but they said, "This is burning my muscle and I haven't had a muscle burn with any exercise I've done for month after a month." And so, there really is very good patient acceptance if you present it in the right context.

Dr. Chris Tucker:

Absolutely. I think that's the art of medicine right there. That's exciting to hear. Most of us who've been athletes in the past and continue to exercise know exactly what you're talking about when you describe that muscle burn. And you're right. I can't imagine somebody with chronic atrophy who have hasn't felt the kind of endorphin rush or the exhilaration of exercise. They've probably lost interest in it and you've given that back to them. So I think that's extremely exciting. I know you have shared with us a number of your personal experiences already. I wanted to maybe dive into that a little further and particularly talk about how are you're using BFR in your practice and in terms of patient responses, tips, or lessons learned, or even any of your own clinical pearls, if you could share those with us.

Dr. Frank Noyes:

Well, thank you very much. And the first is your contraindications. And remember you are using a tourniquet. You do have increase in blood volume. You have to be careful on that postoperatively when you already have swelling. So we started at the second to third week, and we're very mindful of that. We don't want to have any patient that's had previous clotting, even though there has not been any history of that. Well, actually just one, but that was upper extremity clot. Renal disease, any cardiovascular disease at all is not a candidate in the cardiovascular literature. There is a pressure effect of increased sympathetic release of exercising a muscle, and exercising a muscle under reduced oxygen tension. And so, we don't use it in an elderly population. But I will tell you in all of the studies that we have done, it is a very safe technique, but we're using it again in healthy, younger individuals.

Dr. Frank Noyes:

That has to be used in elderly patients I would be very careful of that and I would really look at that literature. The second thing is you need to have a team approach on this. This patient is coming into your clinic. Your therapist is going to see them. We have an athletic trainer that then meets with them. The first couple sessions, they're very tentative on what you're doing. As you set the pressure, you may have to start at 60% of their occlusion pressure. You may have to increase it to get a burn. You have to adjust it during those first five or six sessions so that you are getting it up to an area. Don't go over 80%, but you're getting that up to they say that's a seven. And so, I think that adjustment while you're doing it with the pressure is something that you do need to do.

Dr. Frank Noyes:

And then finally realize we don't know the exact dosage, the pressures are going to change when you exercise. Your pressures are going to go up when you exercise. You want to make sure they don't go up more than 10 units in terms of your past 80. So you have to be very careful of this in your first sessions. So I think the main thing is this is very time intensive. You need to really follow these patients carefully, and you need to let them know that we're going to be doing this for six weeks, Monday, Wednesday, Friday, for six weeks for the chronic atrophy. I will just jump into the postoperative. And I will say to you that it really is a game changer. Postoperative, the patient you're with those patients. Anyway, they really enjoy getting their muscles turned on, enjoy getting that early burn. So start to use that in your patients at about the third week after ACL, we use it any time we can. It's now the standard of practice that any patients that we can get into BFR after surgery, we do so

Dr. Chris Tucker:

You covered a lot of what I was planning on asking you, but just to kind of wrap up one specific question I had for you. I know your study concentrated on the chronic muscle atrophy, and then you just discussed the acute postoperative muscle atrophy issue. How are you incorporating BFR currently into your practice with respect to your indications and protocols? Is this widely applied to all eligible non contraindicated folks, whether they be acute or chronic, or do you have some other selection criteria you use? And side note, how is this reimbursed for physical therapy purposes with respect to insurance for those who are in the private practice sector?

Dr. Frank Noyes:

Yes. Thank you. Those are all very good questions. We use BFR whenever we can. Absolutely. Whenever we can, we need that patient compliance for it, but we're using it. Preop is a very important source. You'll get an ACL and they're not turning their muscle on and take six weeks and get that muscle strength back before you do surgery. That is so important from a preoperative standpoint. Right after surgery, we tell them before surgery what we're going to do right after surgery. We'll use it on whoever we can in three weeks and a very good patient acceptance, and then realize that you're not going to be able to use it on everyone, but I'm going to leave one important point with you. Use the principle of early recognition when your postoperative patient is not responding. Don't get into the patient group that we had in the study where you're out five months, and you've got that tremendous atrophy.

Dr. Frank Noyes:

If your patient isn't responding at 12 weeks and they're getting that atrophy, and they're not turning their muscle on, they have got to get into a BFR program. And if you're not doing it in your clinic, then get them into a clinic where they can now use that because it will be a game changer for them, and it will be a rescue for them. And then finally make sure in your clinic that you have an isometric Biodex, or isokinetic, or a handheld dynamometer. Isokinetic is expensive. Every clinic should have a handheld dynamometer. And don't hold it in your hand. You can use that dynamometer and fix it to the table, and you can get measurements that are very similar to an isometric Biodex. So have the opportunity for your patients to be able to objectively measure their quad and ham strength, preoperatively, and then postoperatively. Very important.

Dr. Chris Tucker:

Those are all fantastic pearls from somebody who clearly has a fair amount of experience with this in learning fro lessons learned in your own practice. So for sharing those with us in particular, that idea of using it preoperatively for the acutely injured ACL was something I had never heard or thought of before. And I really appreciate your suggestion for that. I'm certainly going to roll that into my practice.

Dr. Chris Tucker:

We do use blood flow restriction therapy here at Walter Reed, and across the military fairly frequently for both our wounded warriors, as well as our warrior athletes and recreational and semi-professional athletes who are in the service. So I do have some experience here. I wanted to hear your thoughts on working with your therapist. I have the luxury and really am blessed to work with fantastic therapists here at Walter Reed. And we have a close relationship and we actually see clinic with them. What's your thoughts on the importance of that relationship with the therapist and then sidebar, what's your familiarization with the certification program for people to be qualified to do blood flow restriction therapy?

Dr. Frank Noyes:

So we have always operated with our clinics with being right next to our therapy. And so, that MD, PT, A.T.C team is just absolutely critical. And so, we've always had that as a mode of treatment and we've really popularized that. The question of certification, that's a difficult question. And I know that there are companies that do go through the certification process. We have sent our people through those. And so at that is a good thing. You do have to know what you're doing. We do a certification at Hilton Head. We have our yearly conference that I invite people to come to Hilton Head, and we have a five day MD PT, really intense course. We haven't had it for two years, and I think it's going to be safe to have it.

Dr. Frank Noyes:

So that's over Memorial day. If I can get that advertisement in. And so we do a certified course there, but that's only a beginning certification. So I would look very carefully at your certification courses. And one of them has a very expensive tourniquet quite honestly. And I think it's a great tourniquet. I wish our hospital would buy it and they won't buy it. So we're using standard. Our standard tourniquets that are being marketed. It costs about $300 rather than thousands of dollars. So look at that aspect in your certification, because I think you can get certified in a standard tourniquet that your clinic can use. And I'm certainly though, I certainly call those that have these very sophisticated tourniquets and I certainly like every measurement that you can get in doing this BFRT. Thank you.

Dr. Chris Tucker:

One additional question I wanted to ask you, Dr. Noyes, is, what you think are the most important unanswered questions with respect to blood flow restriction therapy, or knee surgery rehab in general. And what do you see as the most important next steps for advancement in this field?

Dr. Frank Noyes:

So right now, we really don't know the correct way to do BFRT, and we don't know what the pressures should be. And so I think as I mentioned, the tourniquets that are very sophisticated, we do need more studies from that aspect. And those are expensive. They require enrollment of patients. We need to know why certain patients do not respond. And we call that the effect size. We had 15 to 20% that did not respond. We need to know why that is, that they're not responding. I mentioned the importance of objective criteria, and it is just amazing to me. And we did publish this, that only about 20% of clinics today objectively measure quad and hamstring strength, and have the instrumentation to do that. And not to be redundant, but we need to have good objective data on our patients on how they're responding their quad and ham and torque and power.

Dr. Frank Noyes:

And we certainly need this before they return to sport. So I think we're just be beginning with BFRT and we certainly need those really close clinical studies that we can nail down the protocol. And then you mentioned one very important thing, and that's a certification. And how do we certify people that have never used tourniquets before? Surgeons use them all the time when we do surgery and we're very comfortable. But how do we train a whole group of people, therapists and trainers that have never used these tourniquets before? And how do we really certify them and say, "You're going to do this safely for your patients." Thank you for that question. Very important.

Dr. Chris Tucker:

All fantastic ideas for future research and advancement of this very important topic. Before we close, do you have any thoughts or comments that we haven't covered yet, sir?

Dr. Frank Noyes:

No. I think the issue that I mentioned to incorporate this in your practice, go to clinics that are using it. It's time intensive, try to figure out a financial way that you can have your patient come in, and it does not count as a therapy visit. And that's where your trainers can meet the patient, and they can go through this and go through the entire training. And we don't charge them for that particular episode.

Dr. Frank Noyes:

And you mentioned such an important question of, how do we do this financially when we have limited PT visits? And the way we do that is we say, "If we do your surgery, we're going to work out a way that you get these advanced therapy and we're going to decrease the charges and work through that. And if they're giving 20 physical therapy charges, you've got to find another way to make sure that they can get BFRT and not that ha not have that count for their final physical therapy. So finances is a big issue that you've brought up and stressed. Thank you.

Dr. Chris Tucker:

Dr. Noyes, I want to congratulate you and your co-authors again on this very important work and thank you for sharing your time and your thoughts with us today.

Dr. Frank Noyes:

Thank you so much for the opportunity to participate and thank you for sponsoring these podcast.

Dr. Chris Tucker:

Dr. Noyes article titled, Blood Flow Restriction Training Can Improve Peak Torque Strength in Chronic Atrophic, Postoperative Quadriceps and Hamstring Muscles, can be found in the September, 2021 issue of the Arthroscopy Journal, which is available online @www.arthroscopyjournal.org. This concludes this edition of the Arthroscopy Journal podcast. The views expressed in the podcast do not necessarily represent the views of the Arthroscopy Association or the Arthroscopy Journal. Thank you for listening. Please join us again next time.