There is substantial variability in rehabilitation protocols following PCL and meniscus repair surgery. There is often a conservative period where we minimize or avoid hamstring activity.
Biomechanical studies show that hamstring activity can increase posterior translation of the tibiofemoral joint and potentially put stress on a healing meniscus repair.
In this episode, we discuss the science behind this and how we integrate hamstring exercises into our rehabilitation protocols for these patients.
To view more episodes, subscribe, and ask your questions, go to mikereinold.com/askmikereinold.
#AskMikeReinold Episode 378: Hamstring Exercises after PCL and Meniscus Surgery
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Show Notes
• Evaluation and Treatment of the Knee Online Master class
Transcript
Jonny Weaver:
So Rada from Saudi Arabia is asking that he has a post-op PCL reconstruction with meniscus repair, and he’s noticed variations in the protocols regarding hamstring activation: “From your experience, when should I start hamstring strengthening exercises?”
Mike Reinold:
Oh, good question. I like that one here. You almost have a double whammy of hamstring there, meniscus repair and PCL.
Lenny Macrina:
Yeah.
Mike Reinold:
Yeah, that’s crazy. So I don’t know. I mean, Len, why don’t we start with you? What would the biomechanics tell you? And then we can ask Dan Pope what we really do in the clinic.
Lenny Macrina:
Exactly. Well, the biomechanics would say the hamstrings… The tibia gets pulled posteriorly with the PCL frame. The PCL is a restraint to the posterior translation. And so, if you are working on a lot of hamstring activity, it’s going to bias a biomechanical posterior approach to the tibia. We don’t want to stretch out the PCL. Couple in, you have a meniscus repair, I think there’s a detail missing. And if it’s a lateral or a medial meniscus, I think that’s a critical component. If it’s a lateral meniscus repair, it’s not as critical that we hold off on hamstring activity than if it was a medial meniscus repair.
The lateral meniscus, the biceps femoris attaches to the fibula head. So its attachment is not on the posterior knee. It’s not on the capsule or anything like that, unlike the medial meniscus that has direct attachments to the capsule where the hamstring attaches. So the semi-membranosis attaches anatomically back there. So it can pull on the capsule, it can pull on a medial meniscus that’s healing, and that’s the thought. And so you have the coupling of a PCL that you’re trying to avoid posterior translation. You’re trying to avoid pulling on the meniscus and the capsule. And so you want to hold off on doing deeper flexion-type angles of resisted hamstring work. Some say you could do it like zero to 30, where most of the hamstring issues are anyway is that zero to 30 range, and do some isometrics that way, quicker than at the 60 or 90 degree or even deeper than that range of motion.
So that would be my answer. That would be how I would treat it in somebody that if I was treating somebody with a PCL and a meniscus repair, that’s a medial meniscus repair.
Mike Reinold:
And Len, elaborate a little bit on the range of motion because I know you a little bit more, but if you think about the knee, tibial femoral joint, a hamstring contraction at 90 degrees of flexion is almost a direct line to cause posterior translation. Whereas at 30 degrees, like you alluded to, you could start a bit earlier. Biomechanically, it’s less. It’s the same for the meniscus too, right?
Lenny Macrina:
I would say so. And everything I’ve read about this stuff, I did a little prep for this because I was like, “Oh, that’s an interesting question. Let me refresh my memory.” It is true. Yeah. So I would say, and I probably went doing it for the first couple weeks, few weeks, but then you start doing… Because a lot of the protocols are eight, 12 weeks of no resistant hamstring work. It’s not just six weeks. It is eight and 12-week limitations on this stuff. The PCLs tend to stretch out. You don’t want to be a reason why they stretch out. And so avoiding that deep reflection I think is critical because if they get loose, there’s no going back. It’s not like an ACL where they stay tight. They get loose really easily, and you don’t want to be that reason. So I think biomechanically, the lineup pull is going to be different as you mentioned. The translation’s different, and then you’re not worried as much about the meniscus. So, especially if it’s a lateral meniscus repair. So that detail was not in the question, if I recall. So, yeah.
Mike Reinold:
All right. And I think we got to elaborate. I’m going to add a little color to that because I think it’s that important. PCLs do not do as well as ACLs, and it’s because they stretch out. And why do they stretch out? Is it the anatomical repair? Is it part of that? We’ve tried single, we’ve tried double bundles historically. Is it that? Or is it just that life is more stressful on the PCL? So it’s really funny. So I want you guys to Google this. This is the problem with the podcast. I can’t show you this. But I want you to Google this. I want you to look at the graph of tibiofemoral shear force, anterior, posterior. And it’s this huge… It looks like a bell curve. And anything below the line is ACL, anything above the line is PCL.
Well, we argue to death over knee extensions towards terminal knee extension. That’s this little teeny bit under the line on the bottom that we argue about. And then there’s this entire mountain, this iceberg mounted on top that’s PCL stress. So getting out of your chair, putting your shoes on, picking up clothes off the floor has a tremendous amount of strain on the PCL. And that’s why they don’t tend to do well. So even to the point, like Len, doing an isometric hamstring exercise versus getting out of a chair. It’s kind of interesting how we limit that. But I want to get back to the question. When we answer questions, I think —awesome stuff, Len. I don’t know if Dan Pope, I mean, I feel like Dan Pope knows everything, so I want to get Dan. How do you apply this clinically, then? So this person, what would you do? What would you do the first couple of weeks? What would you do the first month, second month? What would you do to integrate hamstring back into a person with a PCL and a meniscus?
Dan Pope:
Yeah, I thought this was really interesting, and I wanted to try to go into literature, see if we have some answers. I didn’t go as deep as… I mean, I think you would have to do a lot more research than I currently did to give you a good answer for this. But I think one of the easy answers is to focus more on closed-chain exercises. And I tend to think about the ACL. I think most folks understand the ACL. When you do a closed-chain exercise, you have the quadricep and the hamstring working together, which is going to reduce the shear forces that you’re going to get within the tibial femoral joint, reducing the strain on the ACL. I think you’re going to have the same thing going on for the PCL as well. So I think you’re probably going to be a lot safer trying to start to work that hamstring from a closed-chain perspective.
In terms of when you can incorporate the open-chain, I thought this was interesting. I was looking through an article from IGSPT. It’s a little old, 2018, but they were looking at all different rehab protocols after PCL surgery, and a lot of the included studies never included any open-chain hamstring, or they included it somewhere between three months and six months. There’s one study that actually did it at six weeks, and they still had decent return to sport and everything else. But in terms of laxity, I don’t know that we really know this. Like you said, the PCL has probably taken a lot more stress than we think it is, in comparison to the ACL. It’s a different anatomic structure as well. So this is a bit of a question mark. I think one of the things I thought of is the ACL history. I think if you look back in time, we started doing open-chain knee extensions kind of earlier and earlier in patients’ rehab.
We found out it was okay to start incorporating them earlier than we once thought. I think it’s… I looked at this study earlier, before this podcast, for Reliedal. They started incorporating open-chain knee extension week four and found no difference in graft laxity. My secondary thought, I didn’t have time to look into this, is that I probably just need to see what the forces are on the PCL during higher-level activities, because one of the things, at least in the ACL, is that something like walking puts more strain on the graft than open-chain knee extension. I just don’t know if that’s the same thing for the PCL. I guess to answer your question, early on, we’d probably focus a little bit more on closed-chain exercises and then just be careful with our introduction of open-chain, talk to the surgeon, see when they’re okay incorporating that and probably using something like blood flow restriction training where we can get some good hypertrophy of the hamstring without putting too much strain on that graft.
Because the big problem, and we know this, is if we avoid something like open-chain knee extensions, particularly for ACL, it’s going to lead to reduced outcomes. So we want to try to make sure we get this muscle back, so we probably have to be more conservative in the ACL. Maybe we just hold off a little bit longer. We use things like BFR for a little bit longer as well, and we double down a little bit more on the closed connect chain exercises. But I wish I had a better answer, and at some point, maybe we’ll sit down and look through all of these studies to try to get a better answer for you. But that was my thought after reading everything.
Mike Reinold:
Yeah, makes sense. Gates, what do you think?
Brendan Gates:
Yeah, I think I just had a question for Lenny and Dan here. I think Lenny and I had this conversation a few months ago. I had a client come in who was treating his PCL rupture conservatively, so non-op. And all the protocols that I went through online and some of the research… It was harder to find a timeline of when to incorporate some hamstring exercises. And so I guess for you guys, are you guys still sticking to that six to eight to 12 week mark, or is the timeline fairly similar to how we treat this after a PCL reconstruction, or can we be a little bit more aggressive? I think anecdotally, this client went through a faster rehab elsewhere and ultimately went back a little too fast. He had started doing some hamstring stuff on the first day of PT there. And not that that’s what caused it, he actually re-ruptured it on his first time back on a basketball court.
So when he came into us, we certainly treated it a little bit more conservatively. But I guess non-op versus the reconstruction, are we sticking with these guidelines? Are you guys familiar with anything different than that?
Dan Pope:
You want to go first, Lenny?
Lenny Macrina:
Yeah, I mean, I probably would. Again, the focus is going to be on quad, stability of the knee, that’s the primary function. I wouldn’t be afraid to do some hamstring work in that shorter range of motion, but it depends on how much of the PCL is torn. It can heal, from what I gather. It is intraarticular, which is a little different than the ACL that’s extraarticular. So there is bathing from synovial fluid. It can kind of… I don’t know. I think it’s just a little different structurally in what the ACL is. So, I think there is a chance for it to kind of heal a little on its own versus an ACL, although there is some research that says the ACL can heal on its own. So I think you have intra versus extraarticular ligaments that act differently. And so I would treat them… To answer your question with hamstrings, I would do some stuff earlier in the range of motion, but not the deeper stuff.
I’d probably wait a good eight to 12 weeks and just let everything chill, as long as his knee… And you’re trying to also monitor translation of the knee too. You can try to do anterior draw, posterior draw, and just see if there’s anything going on. We don’t really do anything else to monitor translation, like a KT anymore, but I think doing some translation-type assessments weekly at least, I think, can also help guide you as well. And then how they feel. Are they feeling instability? Are they feeling anything weird going on in their knee, or feel like it’s a little bit more stable on them? So you’re always getting that from them as well. Yeah.
Dan Pope:
Yeah. Brendan, I was surprised that Kevin and I did an episode on PCL a couple of months back, and we’re looking at return to sport after a grade three PCL. And I was really surprised that it heals a lot better than you might think. And the big problem with those is laxity, and they almost all get lax. And what was really interesting is that return rate timelines were very different based on the study, which I forget the exact timeline, but in NFL, they’re getting back very quickly, somewhere around three months, and they’re almost always using some sort of dynamic brace, dynamic jack brace, I think they call it, which is kind of interesting. It actually reduced laxity. That was one big takeaway I got. So if I had a PCL injury patient, one of the problems is that you want to make sure that it stiffens up.
So this brace is helpful to keep the knee from translating and causing more laxity, and the research studies were showing that to be beneficial. When I saw the return to sport timelines, they’re very quick for NFL, but a lot later. And I was just looking through some studies while Lenny was talking there, and it looks like about half of surgeons will return their conservative patients back before six months, and then half are kind of later.
So I would say faster in general, but then it’s probably going to depend on the severity and also all your criteria-based progressions. Are they getting their strength back? Are they able to do their hop tests? All this stuff that we normally test will probably help to dictate when they’re ready. And it’s probably going to be very different based on the injury. But to answer your question, I was very surprised that a lot of these folks are healing, and they’re looking at MRIs to see if there’s continuity of the PCL, and it seems like it does heal, but the laxity is certainly a problem. So it might not be healing to the same degree or not healing well, but the incorporation of that brace was helpful in those studies.
Lenny Macrina:
And the problem is, even having a surgery, they still get lax. So you try to do everything you can to not do a surgery. PCLs are typically treated conservatively, meaning no surgeries, just go to PT, because if they go have surgery, it’s not always good. So you got to go to the conservative route because the surgery can lead to more laxity. And then you’re like, “Why did I just have a surgery? My knee is just as loose now or a little looser than I like.”
Mike Reinold:
That’s a good point, Len, because don’t think that they’re going non-op versus surgical because it’s like a lesser injury or something like that. That’s not necessarily the case. It’s just that, to my understanding, outcomes after PCL still just aren’t amazing because they get lax, you have early ROA, those types of things. So I think, non-operatively, it is what it is. So you just kind of go. I’ve done hamstrings fairly early. Probably after a month or so, we’ll start doing some hamstring stuff, and you want to try to get them back because it’s non-op. But for me, I’m in no rush to start hamstrings after PCL. Even meniscus, I’m in no rush. You want this thing to be good. So with the ACL, yes, the longer you… If you don’t do quad for a long time, you’re going to be in trouble.
But with PCL, I just think it’s a different procedure. You want this thing to have good outcomes, and you don’t want to stretch out that graft while it’s going through that period. Remember, the graft gets weaker. You’re probably better doing hamstrings day one than you are week six, because the graft is actually weaker. So I would just say I’m not in a rush, I guess is how I would end it. So yeah, always go by what the physician wants, too, because remember, they know more than you from the inside, and they might be protecting something more that you’re unaware of or vice versa. So, kind of keep that in mind. So great question. Thanks for asking. Please head to Apple Podcast, Spotify to subscribe, rate and review, and we’ll see you on the next episode.
