Hamstring strains are incredibly frustrating. You get an athlete feeling great, they go for a sprint, and the muscle grabs again. We have all been there. It is the most common time-loss injury we see in running and field sports.
For years, sports medicine professionals have debated whether biologics actually speed up recovery. Some studies show great results. Other studies suggest they are a waste of money. The conflicting data makes it hard to give our athletes a straight answer when they ask if an injection will get them back on the field faster.
A recent randomized controlled trial finally standardizes the protocol to give us better clarity. The researchers looked specifically at grade 2 tears and used ultrasound-guided injections alongside a traditional rehabilitation program. The results completely change how we should view biological adjuncts in muscle rehab.
Listen to this week’s podcast episode to hear a full breakdown of the study. We discuss exactly how much time these injections can shave off a recovery timeline and how you can apply these findings to the athletes you treat.
To view more episodes, subscribe, and ask your questions, go to mikereinold.com/askmikereinold.
#AskMikeReinold Episode 393: Does PRP Actually Work for Hamstring Strains?
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Show Notes
• Check out our new ACL Return to Sport program
Transcript
Mike Reinold:
Welcome back, everybody, to the latest episode of the Ask Mike Reinold Show. We’re here at Champion PT and Performance reviewing another recent journal article for you today. We have Brendan Gates, Dave Tilley, Kevin Coughlin, Lenny Macrina, Mike Scaduto, and Anthony Videtto all for this article review. Kev, what do we got today? You’re going to take the lead on this one, right? What journal article are we going to look at?
Kevin Coughlin:
Yeah, I thought this was a good one. This is the Efficacy of Platelet-Rich Plasma in Grade 2 Hamstring Muscle Injuries: Results from a Randomized Controlled Trial. It was published in the European Journal of Orthopedic Surgery and Traumatology in 2025, and the authors were Desouza and Shetty. What they were looking at… So,PRP injections in the hamstring. I think this is something, just as an industry, we’re seeing a lot more of PRP, whether it’s in a muscle belly, a tendon, or a ligament, so I liked here that they’re very specific about what they were doing their PRP injections on. They were looking at the hamstring because it’s a very commonly affected area for our athletes. They noted in the study that 27% of athletes in a season will get a hamstring muscle strain, and that there’s 1.2 cases per 1,000 hours of sport. Obviously, that varies a lot based on what sport you do.
We know it’s pretty common in baseball, it’s very common in track and field, very common in soccer, and that there’s also a very high recurrence rate, so they note that within the first year, a lot of athletes, up to 20%, will sustain a recurrent hamstring strain. It seems like our standard physical therapy approach and rehab approach isn’t cutting it, and that’s where there’s this interest in PRP for something to perhaps boost recovery. The principal aim of PRP is to reduce excessive inflammation, facilitate tissue regeneration, expedite recovery, and thereby, in theory, help our athletes return faster. The authors were noting that there’s been other studies that have looked at this, but they tend to include too many different types of issues. Whether that’s different grades of a hamstring muscle strain or a kind of heterogeneity of different injury types, so they tried to get really specific here.
Their study aim, primarily… They were looking at whether standard therapy with ultrasound-guided PRP would improve time to return to sport, and then their secondary outcome, they were actually looking at the tissue via MRI and ultrasound to see if the tissue changed, which I thought was pretty cool. This was a prospective assessor-blinded randomized controlled trial. It spanned over four years. It was at a single-center sports medicine club, and they recruited athletes from the area that were affiliated with different rehab centers or athletic associations. They had 60 athletes included in the study. Their exclusion criteria were any other strain grade that’s not a grade 2, so grade 2 strains only. They did not include tendon avulsion injuries. They did not include any concomitant joint injuries. If you had a hamstring strain in the past year, you weren’t allowed to be in the study. They also weren’t allowing anybody who was getting other biological adjunct treatments, so it was only people who were going to do this study with the PRP.
The baseline characteristics of the group were very similar in terms of age, sport, the mechanism of injury, and, obviously, the grade. They made the diagnosis with a physical exam, ultrasound, and an MRI. Their clinical assessment was looking at pain, bruising, swelling, tenderness to palpation, and joint mobility, and then participants were randomized to either PRP and standard therapy or standard therapy alone. I’ll talk about what was included in the standard therapy. For the injection, they were given their first injection 48 to 72 hours after the initial injury, and then grade 2A were given a second injection seven days after, and grade 2C and 2B were given a third injection seven days after that. That was the protocol that they used. The standard therapy included RICE, so resting, icing, compression, elevation. They were allowed to take NSAIDs, and it included a three-times-per-week structured physical therapy program with supervision from the PT.
The first two weeks were only passive, so they were working on pain management and range of motion restoration. Weeks two to four were a progressive strengthening phase, and then week four and beyond was a return-to-function-in-sport phase. The results of the study… So they found that there was a statistically significant benefit to getting a PRP. The average return-to-sport time was 26.4 days, compared to the standard therapy group was 34 days, so that was an eight-day improvement, and that reached statistical significance. For the secondary outcome, radiographic healing was achieved by day 21 in the PRP group. Sorry. By day 21, 70% of athletes in the PRP group showed near-complete healing versus only 36% in the standard therapy-alone group, so that’s a huge difference, almost double, and that reached statistical significance as well. The re-injury rate was only one patient in the PRP group, and that was over a period of a year, and then the standard therapy group, six patients re-injured. But oddly, that didn’t reach statistical significance, but the authors thought it was worth noting.
For the subgroup analysis, when they looked at different subgrades like 2A, 2B, 2C, there was no difference in PRP affecting one more than the other. It seemed to affect all equally. It also didn’t matter specifically which hamstring muscle was implicated, whether it was semiten, semimem, or biceps femoris, all also had equal benefit. Their clinical implications were that in grade 2 hamstring muscle strain injuries, a PRP injection reduced return-to-sport time. It also led to faster improvements in hamstring muscle architecture, suggesting it can accelerate tissue healing timelines. The findings were statistically and clinically significant, and then I think one thing that they noted that was awesome is that the early administration may be key. They were able to do their first injection within two to three days after the injury, and that might lead to different results if we’re doing this several weeks or even months after an initial injury. That’s kind of the long and short of the study. I thought it was interesting and pretty good.
I think like Mike said in a prior paper, it’d be cool to see just a group that did absolutely nothing as a comparator or maybe if they had a little more advanced therapy for the hamstring, but I think where both groups were doing the same thing, it allows you to at least see how helpful the PRP may have been, so I thought it was pretty good.
Mike Reinold:
Yeah. Kevin, I’d say their return, 26 versus 34 days, give or take, to me, that at least is in line with what you would expect from a hamstring strain, so I would assume the rehab was appropriate enough for that. Wow, another good study that I think is great, just because historically, I think we haven’t known the answer to this as much as maybe we want to. I know, for example, if you go through the past publications from Major League Baseball and going through their database of injuries, if you get a PRP, it actually slows down the healing process. No, I shouldn’t say that. The people with a PRP take longer to get back, and my feedback or my comment on that paper is always that, well, we don’t know, maybe those injuries were worse, and maybe that’s why they got the PRP. It was retrospective, that type of thing.
This thing was fantastic because of the methodology. Really solid methods and very specific injuries and a very specific PRP. My limited understanding of PRP is there’s still multiple ways to do PRP injections that are more or less effective, and maybe even potent in terms of how they actually prepare it, so to us, it shows that there is a way that, man, you can come back eight days sooner, you’ll have greater healing three weeks out, and then more importantly, a lower chance of re-injury? That’s awesome. What do you guys think? Anyone jump in here. Anything that surprised you or you thought was a little different from your perspective? Dave?
Dave Tilley:
Yeah, I’ll just be quick because I don’t want to steal all the thunder, but I had a couple of thoughts. One is I agree. I love the inclusion criteria. Having an ultrasound, MRI, a board-certified sports med physician… They were very specific about who was getting this intervention. I think that’s important, because a grade 1 strain, you probably don’t tell anybody about and, obviously, grade 3 is a whole different ballpark of treatment, so I really like that inclusion. You mentioned it, but the recurrence rate was what stuck out to me the most. We see a lot of people who have unfortunate, really high recurrence rates. Every four to six weeks, we do really good therapy, they get back, and then they’re randomly at another. They follow the workload progression well, and they’re just sprinting in a game and they feel it again, and then they’re all the way back.
It’s very mentally draining for an athlete to not be able to get through a season because every time they try to get above 90 or 100% or get back to full, they keep tweaking their hamstring, and then it’s all the way back to the beginning. That’s a very frustrating loop for a lot of people to be in, so that was really cool to see the very low recurrence rate in someone, and that was up to 24 months. That wasn’t in a week or two or three weeks. That was substantially through a season, which is good. The only other thought that I had is, man, can you imagine how awful that must feel to get PRP directly in the spot that hurts right after it happened? That’s what was on my mind. PRP hurts a lot. I have two people who just got it, and they were like, “That was the worst experience of my life, getting needled in my hamstring,” let alone a PRP, so shout out to these people.
Mike Reinold:
I agree. I agree. What else?
Lenny Macrina:
One thing that jumps out at me, limitation of the paper, is we don’t know the concentration of the PRP. I don’t think they ever said it. I’m reading it again now, and I still don’t see what their concentration was, and that seems to be a critical factor. Could it be better, or did they use an appropriate concentration that seems to be acceptable and clinically beneficial and significant? Because it seems to be over about three and a half, four parts per billion is what is critical in a PRP. It looks like they use leukocyte-rich PRP, which seems to be the standard of care for a muscle injury, so that was good. But I was surprised that they didn’t want to at least brag on their concentration of PRP, because it seems like that’s a critical aspect of what docs are going towards. A more concentrated PRP seems to be better for these type of injuries. But overall, I think it’s an interesting study. I think I’m getting more and more on the PRP bandwagon than what I used to be two, three, four years ago, and even beyond when I was very skeptical, so encouraging.
Mike Reinold:
For hamstring strains.
Lenny Macrina:
For hamstring strains.
Mike Reinold:
Based on this.
Lenny Macrina:
Grade 2 hamstring strains. Yes.
Mike Reinold:
Layman’s. Yeah. What do you got, Anthony?
Anthony Videtto:
Yeah, again, I think this is a really interesting study, especially with the recurrence rate of these hamstring strains being so low after PRP. I think that’s awesome. The only thing I wanted to bring up was all of these athletes got the PRP within 48 or 72 hours after the injury. In my head, it’s like, how practical is that in our setting? I see someone for a hamstring strain, maybe it’s the day after, maybe it’s a week after, but… Okay, so let’s say it’s a day after. Now I only have 48 hours to try to get them an ultrasound, an MRI, and then also a PRP within that same window? It just seems very difficult in maybe our standard of care as PTs.
I’d argue at the professional level, that seems like it’s a lot more appropriate, or maybe the high-level college setting as well. But I’m just thinking if I’m in the clinic at Champion and I have a grade 2 hamstring strain come in, how quickly am I going to be able to facilitate this process theoretically if I’m trying to get them a PRP within this 72-hour window or five-day window they kind of mentioned? That’s the only hesitation that I might have with this study.
Mike Reinold:
Yeah. That’s a real one though, Anthony. I mean, I think that is important, and it goes back down to having just a good relationship with somebody to get them in pretty quick. I feel like we could get people in. We have enough people that we know that we probably could, but you’re right, and not everybody could. That’s a really good point. Mike, what do you think?
Lenny Macrina:
Oh, sorry. One more thing I meant to mention earlier was, as a PT, it’s always frustrating that they don’t talk about what they actually did for a standard of care treatment. It’s just that they had different phases, phase one, two, and three of calm down, build up, and then return to sport. What does that mean? What were they doing? I’d like to know more details of what the actual rehab is.
Anthony Videtto:
Yeah. They also didn’t really include any return-to-sport criteria either, so it was like, were they ready to return to sport at that time? Did they just look better, and they were like, “Okay, you can start playing again”? I would’ve loved to see some return-to-sport stuff in there as well.
Mike Reinold:
If you’re a surgeon and you’re listening to this podcast, which you’re not, I get it, but if you were, just include your PT in the paper. What is wrong with you guys? Just say, “Hey, write a paragraph for me on what you did.” I mean, it’s that easy. That’s why these clinical papers that people like Kevin Wilk and us, that we’ve done over the years, and our colleagues, everybody appreciates the collaboration in there. But my gosh, just get your PT to write a paragraph. All right, sorry. Mike, what do you think?
Mike Scaduto:
Again, just like Anthony, looking at it from the practical side of things. I know this is in the European Journal, so maybe the cost of a PRP is different in Europe, if that’s an out-of-pocket cost or not, and maybe this will go a long way in terms of insurance coverage for PRP in America, specifically for hamstring strains. But to the best of my knowledge right now, it’s not covered by insurance, so if we’re doing repeat one, maybe two PRP injections, that can be in the ballpark of $3,000. Is that eight days of faster return to sport… Is that worth $3,000 for a high school athlete? I don’t know, that’s a family decision, so I think it definitely… We can present this research to people. I think there’s going to be other considerations, whether that’s practical for them. But again, maybe this paper can go as evidence to insurance companies, and maybe they’ll start covering it. I have no idea how that works.
Mike Reinold:
Yeah. No, that’s a really good point though, Mike, on that. This isn’t cheap. Eight days for $3,000, that’s a really good way of putting it. To your point, not our decision, theirs, but good stuff. Gates, what do you think?
Brendan Gates:
Yeah, I think just wanted to hammer back a couple points. When I was in college, I got PRP in both knees, and then I played in a game three days later, and so it obviously didn’t do anything, so I think it’s nice that we’re finally paying attention to you have to treat the procedure with some care, and like any procedure, you need to do a little bit of a pointed rehab afterwards. The four plus weeks of this is nice to see that there’s an outline, but I agree, I do wish there was a little bit more specificity on the protocol that they used. Lenny talked about the platelet concentration. I think that’s important. The minimal effective dose is worth noting, and I think if you don’t know what you’re getting, that can be to your detriment. You don’t want to just waste money, like Mike said. One thing that I had a question on, Kev, was they said leukocyte-rich. Obviously, the other option of PRP is leukocyte-poor. Is there a quantifying level of leukocytes that makes it rich, and is more better? Do we know that yet?
Kevin Coughlin:
I wish I knew. I honestly don’t know the answer to that.
Lenny Macrina:
I looked this up a little last night because I was curious, to reestablish this in my head. I think when they spin it down, there’s different levels of, I guess, sections. It spins out into the heavy stuff goes to the bottom and then they can take just the top layer, which is going to be your leukocyte-poor. It’s just the plasma that they can inject. That’s going to be more for a joint, like an OA joint or something like that. The leukocyte-rich is the next layer down, where it has more of the white blood cells, which is what seems to be a better option for muscle injuries. You also have platelet-poor plasma, PPP, that is kind of coming out right now that could be even better than leukocyte-rich. It’s tough to keep up with all the terminology and all the biology, but I think it’s how they spin it down, the different layers that develop, and where they aspirate or pull out the different layers determine…
I guess they could quantify. They could run tests, but that’s probably an extra step to figure out what exactly is in it. But I think them just pulling out the different layer that develops after the centrifuge, it, I think, is the step that determines is it leukocyte-rich or leukocyte-poor, and then it’s obviously where they’re injecting it. A joint’s going to be poor, a tendon or a muscle is going to be leukocyte-rich. Yeah, that’s what I understood.
Dave Tilley:
Just one more quick point. I remember when Dr. Latzka came to us and talked. He said that the math and the calculation based on the person, the injury, their weight, there’s a huge amount of math that goes into doing it well. I remember him saying that the patient has to be there for 30 to 45 minutes after they draw for them to do all these crazy calculations, and if we don’t do that well, it more or less is not doing what we think and/or at all. He would be better to speak to that, but I think there’s a lot of heavy math and specificity that goes into the proper dose, the proper person, and the right tissue spot. Yeah.
Lenny Macrina:
The extra centrifuge step to get it down to four parts per billion. I think there’s an extra step that not many places do or utilize, at least when I spoke to him a year ago, was the centrifuge. The extra step of getting it even richer into that deeper concentration is what many don’t do or hadn’t done, and I don’t know if it’s been updated, but it seems like that’s the key step that many miss. Again, we don’t know what went on in this study.
Mike Reinold:
Those probably have a huge…
Lenny Macrina:
Cost.
Mike Reinold:
…Impact on the outcome and the cost.
Lenny Macrina:
Yes, yes. Right.
Mike Reinold:
No, it does, and the time. I think a lot of places, they don’t want to put in the time. You know what I think the biggest take-home message of all this is? Is that PRP is evolving, and I think we just started doing PRPs with everything, and we were a little bit sloppy with maybe the preparation, how we did it, just historically here. I think the big take-home for me is to find someone near you that does this and is an expert at this, and they actually have centers that this is what they do, this is their specialty now. It’s not necessarily going to the surgeon. They actually have people that have their own specialties, or their surgeons have their own people that do them within their practice. Find somebody that does this and does a great job with it. I think that’s the best-case scenario here to make sure that you’re getting the right type of PRP, is that you’re sending them to an expert with that. I think that’d be a great relationship too, even going back to the point from Anthony on, can you get somebody in quick?
Yeah, if there’s a center for biologics that is in your area that you can send them to, they’re going to love getting them in within 48 hours, because they want a good outcome too. They want to maximize that outcome, so that’s probably how they’re going to operate. I urge you to check your area and see if these are popping up in your area. There’s a huge subspecialty that’s happening in orthopedics that kind of focuses on this, so take a peek. Awesome. Thank you, Kevin. Great article review. Another good article. Again, I think that that is making us all better. I know we’re better here at Champion. Hopefully, you’re better from listening to this too. But yeah, again, just subscribe, rate, review on wherever you listen to your podcasts, and we’ll keep doing these episodes for you. Thanks so much.
