Why You Can’t Inject a Torn Knee ACL with Ultrasound

by Chris Centeno, MD /

Receive a Regenexx® Patient Info Packet by email and learn why it's a superior regenerative solution.

inject acl with ultrasound

When we first began injecting ACL tears with stem cells many years ago, we tried quite a few techniques. At first, it was a very difficult injection that wasn’t reliable. However, after some anatomy review and testing several methods, we finally settled on a procedure that produced reliable results and then began teaching that through a nonprofit course. This morning I’d like to review a case that shows why injecting an ACL with ultrasound only could cause problems.

Can We Inject the ACL?

The anterior cruciate ligament, or ACL, is a ligament that stabilizes the knee in front-back and rotational directions. It can be torn in sports or trauma, and these days it’s often surgically removed when torn and replaced with a tendon graft. However, there are problems with ACL surgery, so the idea of keeping your existing ACL is attractive.

When I first tried to inject the ACL, it was after speaking at a prolotherapy conference. This most basic of regenerative-medicine injections involves using a solution that causes a brief inflammatory healing reaction. However, almost all prolotherapy at the time (and most of it still to this day), is performed blind without guidance. In the case of the ACL, this meant that the physician stuck a needle inside the joint and used outside landmarks to ensure that he or she was injecting into the ligament. After I was back in my practice, I decided to use the blind technique with guidance to determine how often the doctor was really injecting into the ligament. Regrettably, I wasn’t able to accurately inject into the ACL using this technique nor did I believe that many of my prolotherapy colleagues were really injecting it either.

Over the next few months, I set out to document that I was injecting the ACL. However, while I would get lucky in some patients and have solid documentation of an ACL injection, the procedure was hit or miss. One of our doctors suggested trying it with ultrasound as he had seen that procedure at a recent course. The good news was that we could visualize the front part of the ligament (insertion), but it was all but invisible at around one-third to one-half way up or more. About that time, we were experimenting with a mini-arthroscope, and we were able to inject the ligament with that device (which I think is the first ACL injected with stem cells using arthroscopy). The issue here was that it seemed silly to put a patient through an arthroscopy just to inject a ligament (basically using a sledgehammer to put in a finishing nail).

Around that same time, I dug into the literature about ACL anatomy and made a breakthrough using fluoroscopy (real-time X-ray). I figured out how to reliably inject the bottom (insertion) and top (origin). Once this happened, we didn’t need the arthroscope, as an injection is always less invasive than a surgery. In addition, we began to see that one of the problems with the ultrasound method was that the torn ACL often leaked out the back of the synovial covering of the ligament about two-thirds of the way up. So by injecting these torn ligaments with ultrasound, while it looked like the doctor was injecting the whole ligament, the upper part wasn’t getting any cells. Finally, we also began to observe that there was a correlation between how well we were able to cover the ligament with cells and the extent of ligament regeneration we saw on MRI. After that, a smart fellow named Dr. Bashir also helped to make the procedure even better.

Images That Explain Why Ultrasound ACL Injections Are Suboptimal

Since we invented this ACL stem-cell-injection technique, we get patients from all over the world. In this case, a professional athlete had an ACL tear and went to a respected surgical orthopedic clinic. The tear was read out as “partial,” and surgery wasn’t recommended, so a nonsurgical provider injected bone marrow concentrate into the ACL using ultrasound. The patient was then braced and went back to working out hard. I was told by the athlete’s trainer that all providers thought that the ACL was healing one month later, but when I looked at both films (before and after the injection), the ACL had, in fact, substantially worsened. There was now a new retracted part in the area where an ACL ultrasound image couldn’t reach, the tibial offset measurements that we use to determine candidacy had substantially worsened, and there was new bone swelling. Why had this happened when this technique is usually very reliable in the right patients? Meaning that if performed properly, we usually see the opposite on MRI (i.e., evidence of ACL regeneration, a stable or the same offset measurement, and a reduction in bone swelling). While it’s possible that a poor result would have occurred regardless of injection technique, given the candidacy data we’ve amassed, that seemed unlikely (i.e., he was an excellent candidate coming into the procedure).

I think the image below may help explain what happened. Note that the image on the left below is an ACL ultrasound, and the image on ACL mri vs ultrasoundthe right is an MRI of the ligament. On the left, note that the yellow-dashed line represents the small part of the ACL that can be easily seen using ultrasound. Note also that the yellow-dashed line represents the part of the ACL that can barely be seen with ultrasound (it’s in shadow). Then look at the MRI on the right , which shows the ACL outlined in white dashes and a yellow box that represents the small part of the total ACL, which can be visualized with ultrasound. Note that the ACL in the white dashes travels up and well beyond the limited filed of view of the ultrasound.

ACL injection fluoroNow consider this image from a fluoroscopy injection (left). The ACL ligament is outlined (dark), but the injection at the bottom, where you would inject using ultrasound, dumps out the back of the torn covering of the ligament and ends up in the back of the knee joint rather than in the top part of the ACL (follows the course of the yellow arrow). This is what I believe happened in this athlete’s knee. The top part of the ACL (origin) was never treated with cells, so it eventually ruptured. Note that there is a needle in position (straight line that comes from the left to right) to inject the top part of the ligament.

Now consider this image of a properly injected ACL tear whereproperly injected fluoro ACL both the top and the bottom of the structure have been injected. Note that the dark ACL (anteromedial bundle) now extends from the bottom to the top. Also note that the other ligament bundle (posterolateral, or PL) also extends all the way up. How? Using this real-time X-ray guidance, the doctor can now see and target the top of the ligament. If the injection from the bottom doesn’t get to the top, he or she can inject the ligament up high to close the gap.

The upshot? While you can likely inject an intact ligament with ultrasound and have it work reasonably well, a torn ACL is another matter. While fluoroscopy is more expensive to own and operate, it’s needed to perform a proper injection of the torn ACL with stem cells. So please, please, please don’t inject a torn ACL with ultrasound, doubly so if the patient depends on that knee to make a living!

Leave a Reply

Your email address will not be published. Required fields are marked *

4 thoughts on “Why You Can’t Inject a Torn Knee ACL with Ultrasound

  1. Holly Roge

    Any chance you can highlight a hip labrum tear with osteoarthritis?

    1. Regenexx Team Post author

      Holly,

      Holly,
      The arthritis and the labral tear go hand in hand, as one of the biggest contributing factors to arthritis is the wear and tear of instability. Please see: http://www.regenexx.com/hip-labrum-stem-cell-procedure/ and http://www.regenexx.com/side-effects-of-hip-labrum-surgery/ and http://www.regenexx.com/helping-a-college-athlete-avoid-hip-labrum-surgery/ and http://www.regenexx.com/hip-labrum-surgery-complications/

  2. Kathy Santi

    I am 65 & suffered a complete,full thickness posterior medial horn root tear of my left meniscus 6 weeks ago.I hope that I am a candidate for stem cell therapy.Thank you,Kathy Santi

    1. Regenexx Team Post author

      Kathy,
      We treat posterior root tears of the meniscus, however each case is evaluated individually for Candidacy. Please see: http://www.regenexx.com/meniscus-tears/ and https://regenexx.com/blog/a-tale-of-two-siblings-and-a-knee-replacement-alternative-at-one-year-out/. If you’d like to see if you would be a Candidate, please submit the Candidate form.

Chris Centeno, MD

Regenexx Founder

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

Get Blog Updates by Email

Get fresh updates and insights from Regenexx delivered straight to your inbox.

Regenerative procedures are commonly used to treat musculoskelatal trauma, overuse injuries, and degenerative issues, including failed surgeries.
Select Your Problem Area
Shoulder

Shoulder

Many Shoulder and Rotator Cuff injuries are good candidates for regenerative treatments. Before considering shoulder arthroscopy or shoulder replacement, consider an evaluation of your condition with a regenerative treatment specialist.

  • Rotator Cuff Tears and Tendinitis
  • Shoulder Instability
  • SLAP Tear / Labral Tears
  • Shoulder Arthritis
  • Other Degenerative Conditions & Overuse Injuries
Learn More
Cervical Spine

Spine

Many spine injuries and degenerative conditions are good candidates for regenerative treatments and there are a number of studies showing promising results in treating a wide range of spine problems. Spine surgery should be a last resort for anyone, due to the cascade of negative effects it can have on the areas surrounding the surgery. And epidural steroid injections are problematic due to their long-term negative impact on bone density.

  • Herniated, Bulging, Protruding Discs
  • Degenerative Disc Disease
  • SI Joint Syndrome
  • Sciatica
  • Pinched Nerves and General Back Pain
  • And more
Learn More
Knee

Knees

Knees are the target of many common sports injuries. Sadly, they are also the target of a number of surgeries that research has frequently shown to be ineffective or minimally effective. Knee arthritis can also be a common cause for aging athletes to abandon the sports and activities they love. Regenerative procedures can be used to treat a wide range of knee injuries and conditions. They can even be used to reduce pain and delay knee replacement for more severe arthritis.

  • Knee Meniscus Tears
  • Knee ACL Tears
  • Knee Instability
  • Knee Osteoarthritis
  • Other Knee Ligaments / Tendons & Overuse Injuries
  • And more
Learn More
Lower Spine

Spine

Many spine injuries and degenerative conditions are good candidates for regenerative treatments and there are a number of studies showing promising results in treating a wide range of spine problems. Spine surgery should be a last resort for anyone, due to the cascade of negative effects it can have on the areas surrounding the surgery. And epidural steroid injections are problematic due to their long-term negative impact on bone density.

  • Herniated, Bulging, Protruding Discs
  • Degenerative Disc Disease
  • SI Joint Syndrome
  • Sciatica
  • Pinched Nerves and General Back Pain
  • And more
Learn More
Hand & Wrist

Hand & Wrist

Hand and wrist injuries and arthritis, carpal tunnel syndrome, and conditions relating to overuse of the thumb, are good candidates for regenerative treatments. Before considering surgery, consider an evaluation of your condition with a regenerative treatment specialist.
  • Hand and Wrist Arthritis
  • Carpal Tunnel Syndrome
  • Trigger Finger
  • Thumb Arthritis (Basal Joint, CMC, Gamer’s Thumb, Texting Thumb)
  • Other conditions that cause pain
Learn More
Elbow

Elbow

Most injuries of the elbow’s tendons and ligaments, as well as arthritis, can be treated non-surgically with regenerative procedures.

  • Golfer’s elbow & Tennis elbow
  • Arthritis
  • Ulnar collateral ligament wear (common in baseball pitchers)
  • And more
Learn More
Hip

Hip

Hip injuries and degenerative conditions become more common with age. Do to the nature of the joint, it’s not quite as easy to injure as a knee, but it can take a beating and pain often develops over time. Whether a hip condition is acute or degenerative, regenerative procedures can help reduce pain and may help heal injured tissue, without the complications of invasive surgical hip procedures.

  • Labral Tear
  • Hip Arthritis
  • Hip Bursitis
  • Hip Sprain, Tendonitis or Inflammation
  • Hip Instability
Learn More
Foot & Ankle

Foot & Ankle

Foot and ankle injuries are common in athletes. These injuries can often benefit from non-surgical regenerative treatments. Before considering surgery, consider an evaluation of your condition with a regenerative treatment specialist.
  • Ankle Arthritis
  • Plantar fasciitis
  • Ligament sprains or tears
  • Other conditions that cause pain
Learn More

Is Regenexx Right For You?

Request a free Regenexx Info Packet

REGENEXX WEBINARS

Learn about the #1 Stem Cell & Platelet Procedures for treating arthritis, common joint injuries & spine pain.

Join a Webinar

RECEIVE BLOG ARTICLES BY EMAIL

Get fresh updates and insights from Regenexx delivered straight to your inbox.

Subscribe to the Blog

FOLLOW US

Copyright © Regenexx 2019. All rights reserved. | Privacy Policy

*DISCLAIMER: Like all medical procedures, Regenexx® Procedures have a success and failure rate. Patient reviews and testimonials on this site should not be interpreted as a statement on the effectiveness of our treatments for anyone else.

Providers listed on the Regenexx website are for informational purposes only and are not a recommendation from Regenexx for a specific provider or a guarantee of the outcome of any treatment you receive.