Outside Ankle Pain? What Could Be Wrong?

Outside ankle pain is common. So what’s here that could be causing your pain? How should this be diagnosed? Let’s dive in.

What’s Here?

There are few things that can cause outside ankle pain. First, this is where the peroneus brevis and longus tendons live, so small tears in those ligaments or degeneration (tendinopathy) can cause pain. Next, nerves live here, so an irritated nerve in your back can mimic ankle pain. Finally, strong ligaments are here that stabilize the ankle. This last bit is where we’ll focus today, as if these are stretched, the ankle joints may get trashed.

Regenexx Updates in Your Inbox

Join our free newsletter.
Join the Regenexx Newsletter
Subscribe to Blog

What Is Stress Ultrasound Imaging?

If we want to see if ligaments are strong, that can be a challenge with static imaging like MRI. This imaging type will show big tears in ligaments, but smaller tears causing laxity usually won’t show up. So how can we diagnose those? We need to stress the ligaments while we’re looking at them. There’s only one type of imaging that can do that: stress ultrasound.

You might most be familiar with ultrasound as an imaging machine used during pregnancy to see babies in the womb. We can use the same technology, though tweaked a bit, as a diagnostic tool for many things besides just pregnancy, and one of those things is to visualize ligaments and diagnose instability. As you can see in my video above, for an ankle, I can place the ultrasound probe on the ankle and as the ankle is stressed, I can visualize how the ankle ligament responds.

When a loose ligament is challenged with stressed movement, I will see it give way and stretch too much, allowing ankle instability. If the ligament doesn’t give way or stretches very little, I can rule out ankle instability. Most patients who have loose ankle ligaments will have negative MRIs, and a critical diagnosis will be missed, and as with most things, the sooner loose ankle ligaments are addressed, the better, as leaving them untreated can create worse problems down the road.

Outside Ankle Pain: One Patient’s Ligament Issues

Recently, a patient came to see me for his outside ankle pain, centered just above the ankle. He’d had no known injury that he could recall; he just knew that the ankle pain came on suddenly about two or three months prior. He is a very active athlete who plays hockey and Lacrosse, so it is possible he had injuries, such as twisted ankles or sprains, throughout the years that may have contributed to his outside ankle pain over time.

Using stress ultrasound imaging (watch my video above to see this patient’s stress ultrasound), I was able to determine that his outside ankle pain was due to subtle issues with some of the ligaments in his ankle. This is not something the average family doctor, podiatrist, or orthopedic surgeon would have found as it would require stressing of the ankle ligaments while observing them under ultrasound to properly diagnose.

What was wrong with this patient’s ligaments that caused outside ankle pain? They were too loose, and there were multiple partial tears. Five of his ankle ligaments, in total, were damaged. These ligament issues caused instability in his ankle joint, between the fibula (the smaller lower-leg bone) and tibia (larger lower-leg bone), as due to the loose ligaments, the joint was now moving way too much. This created pain because the ankle was moving in ways it wasn’t supposed to. Why wouldn’t the average doctor catch this issue? Because the typical diagnostic tool, an MRI scan (which, as already mentioned, can only provide a still image), often misses this diagnosis.

Join us for a free Regenexx webinar.

Treating Outside Ankle Pain with PRP, Not Surgery

Even if a family doctor or orthopedic physician had discovered these ligament issues, in my experience, neither of this patient’s ligament issues would have required surgery to repair. Ligament surgery, in fact, has been shown to be unable to restore normal ankle and foot motion, which can lead to more problems in the ankles and even with alignment issues up the kinetic chain, into the knees, hips, and so on.

In interventional orthopedics, we would provide a precise injection of high-dose PRP under ultrasound guidance into the patient’s ligaments and do another stress ultrasound in two months to check on the patient’s progress. Most of these patients require anywhere from one to three treatments.

So if you’ve been struggling with outside ankle pain and your doctor just can’t seem to find a solution, it’s possible he or she is simply using the wrong diagnostic imaging tool, so find a doctor who knows how to diagnose and nonsurgically treat ankle instability.

The upshot? Your outside ankle pain may be due to loose ligaments. Oftentimes, the only way to get that accurately diagnosed is by using an ultrasound machine and a doctor who knows what to look for. If you have this problem, you almost certainly don’t need surgery, just some ultra-precise injections of PRP or bone marrow stem cells.

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

If you have questions or comments about this blog post, please email us at info@regenexx.com

NOTE: This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and related subjects. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if a treatment is right for you.

U.S. Locations by State, Metro Area and City

International Locations by Country


Cayman Islands

Taiwan, Province of China

United Kingdom