Home › Blog › ACL Tear Stem Cell Injection: Ultrasound vs. Fluoroscopy

There’s been a lot of controversy lately over whether an ACL Tear Stem Cell Injection can be properly performed using ultrasound. Some physicians cite a paper published in 2015 that seems to show ultrasound can get the job done, and while this may be true for intact ACLs, where injecting them from the bottom of the knee at the tibial insertion is not too difficult, torn ACLs are a whole different ballgame.

We invented and have the most experience in the world with injecting ACL tears with stem cells, and one thing our experience has taught us is that torn ACLs cannot be effectively injected using ultrasound with its limited field of view and that they require fluoroscopic guidance to really get it right. Today, I will demonstrate this by sharing an injection I performed on one of my patients for an ACL tear.

Demonstration of an ACL Tear Stem Cell Injection

The truth is, most of the physicians who are stirring up the ultrasound controversy really don’t have much experience with ACL injections, either ultrasound-guided or fluoroscopy-guided, so I thought I’d demonstrate today what these procedures look like. There are many images in the short video above to enhance your understanding of the procedure, so be sure to watch.

My patient is a nationally ranked teenage tennis star, and she had an ACL tear, very common in athletes, and needed stem cells. My original injection was at the bottom of the ACL at the tibial insertion (the spot where the ACL meets the top of the tibia bone of the lower leg). The problem is, after three or four repositionings of the needle at the bottom, even under fluoroscopy,  I’m limited by how high the injectate (the material I’m injecting—stem cells) can go, and instead of continuing up the ACL, it’s just dumping out the back into the joint space (see video). It’s important to note here, just injecting at the bottom where you would normally inject using ultrasound guidance, this is all we would get. Meaning the entire top part of the ACL (the origin) would be left without stem cells. 

Hence, I still have a lot of the ACL I need to get stem cells to, and using fluoroscopy I can do this by repositioning my needle to the ACL origin, or the point where the ACL meets the femur (the upper-leg bone). Once I reposition and inject the origin (see the video), it’s looking better. I have coverage at the top and bottom, but I still need coverage in the middle. I reposition the needle and get to work on the middle of the ACL, and you will see in the video how involved it is to get as much of the middle as possible.

The video demonstrates all of the areas I was able to get stem cells to in my young tennis athlete’s ACL tear. Considering how torn the ligament was, I was able to get pretty good coverage with fluoroscopy. While I would have been able to get some coverage with ultrasound, I would have been very limited, and it wouldn’t have been possible to get stem cell coverage throughout the majority of ACL. So an ACL tear stem cell injection using ultrasound only would not have been adequate to treat this patient’s ACL tear.

More About That Paper on ACL with Ultrasound

The paper was published in PM&R journal, and the purpose of the study was to validate ACL injections using ultrasound. Latex was injected into ten cadaver knees under ultrasound guidance, and results showed that the latex did indeed make it from the bottom through the top of the ACL. But our concern is ACL tears specifically, and cadaver parts don’t come with known ACL tears. So this study doesn’t cover injecting ACL tears using ultrasound and, therefore, doesn’t apply here.

The upshot? Sure, like the cadaver study shows, you can be reasonably successful injecting an ACL using ultrasound guidance—an intact ACL. But for patients with an ACL tear, especially athletes who want to get back in the game as quickly as possible, you’re going to need the right technology to perform a proper injection. And that right technology for an ACL Tear Stem Cell Injection is fluoroscopy.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile