Updated: May 30
You don’t need a scan for us to be able to diagnose you with Achilles tendinopathy, but they can be useful. In this article, I discuss what a scan can and cannot tell you and when it may make sense to get one.
The terms tendinitis, tendonitis, tendinosis, and tendinopathy mean the same thing for all practical purposes, and we use these interchangeably in our articles.
In this article:
How is Achilles tendinopathy diagnosed?
Achilles tendinopathy is diagnosed by listening to the patient’s history of how the injury happened as well as where and when they have pain. A group of researchers investigated ten clinical tests that are commonly used to confirm the diagnosis, and they found that the two that were the most accurate were also the simplest:
If the patient points to the painful area and it's the mid-tendon.
If you can feel a “swollen” lump in the tendon when you squeeze it.
So you can see that scans aren’t really needed in the first instance.
What types of scan can be useful?
X-rays: These are a waste of time and money. They show bones, not soft tissue such as tendons, and can’t be used to diagnose Achilles tendinopathy. Some clinicians order them to look for heel spurs (a growth on the heel bone). But there are many people with heel spurs who do not have any problems with their Achilles tendons, so I wish people would stop focusing on them.
Ultrasounds scans: These are extremely useful for diagnosing Achilles tendinopathy. In tendons with a tendinopathy, they can show changes in the tendon structure, and you can measure the tendon diameter and check the blood flow (neovascularization). Some ultrasound machines can also measure the stiffness of the tendon, but we’re not quite sure yet of the clinical relevance of this.
MRI scans: These are just as useful and can also show you changes in tendon structure, but you can’t visualise the blood flow.
Which is better, ultrasound or MRI? They appear to be equally effective in diagnosing Achilles tendinopathy. Ultrasound is much cheaper and can be done in a few minutes. If you go to a skilled sports medicine doctor, they can usually do it for you right there in their consulting room.
What scans can tell you
They can be used to confirm your diagnosis and show the changes in the tendon structure. However, scans can also sometimes show up false positives (where it looks as if the tendon is injured when it’s not) as well as false negatives (where it doesn’t show anything wrong, but actually the tendon is injured).
It can show up other things that may be contributing to your problem, e.g. a plantaris tendon that is rubbing on the Achilles or a tear in the tendon. That’s why I would always encourage a patient to get a scan if they have been doing all the right rehab things for at least 12 weeks and not seen the results that we expected.
What scans cannot tell you
At the moment, we can’t tell by looking at a scan how bad your injury is or how long it will take to get better. There are interesting studies being done where they measure tendon stiffness, but at the moment we don’t fully understand how that correlates to your function and recovery. In fact, we don’t yet actually know what should be classed as “normal” tendon stiffness.
How we can help
Need more help with your Achilles injury? You’re welcome to consult one of the team at TMA online via video call for an assessment of your injury and a tailored treatment plan.
We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine. But at Treat My Achilles we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.
About the Author:
Khan, K., et al. (2003). "Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study." British Journal of Sports Medicine 37(2): 149-153.