Calcific Achilles tendonitis – Three types and their treatments
- Maryke Louw
- 3 hours ago
- 11 min read
So, you’ve been diagnosed with “calcifications” in your Achilles tendon. But which of the three types of calcification do you have? Here’s why this matters, how to distinguish between them, and what to do about it in each case.
Remember, if you need help with an Achilles injury, you're welcome to consult one of our physio team via video call.
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:
Each type of calcification shows up in different ways on scans, so your doctor will be able to tell what type you have by looking at your scans.
👉 I’m discussing each type of calcification as if it fits into a nice, tidy box, but in reality, it is possible to have a combination of these – it’s quite common for people to have hard calcifications and bone spurs, for instance.
To complicate things even further, researchers often don't specify the type of calcification they are writing about or use the wrong terminology for the wrong type 🙈 But we’ve combed through the research and teased out the differences to help you figure out what might apply to you.
Let’s look at each type and what treatments might work best.
1. Hard calcium deposits associated with chronic Achilles tendinopathy or tendonitis
This is the most common type of calcification in the Achilles tendon.
The deposits
These calcium deposits consist of salty minerals (calcium phosphate salts) and form hard little lumps that cannot be absorbed by the body. It is thought that the minerals leak out of the injured tendon cells to form the deposits; so, this is a byproduct of chronic Achilles tendinopathy.
However, not everyone with chronic Achilles pain develops this, and there is evidence that other factors in your general health (diabetes, high cholesterol, etc.) can increase your chances of developing these.
What it looks like on scans
This type of calcification shows up on scans as small specs or lumps throughout the injured part of the Achilles tendon. The tendon itself usually also shows signs of long-term injury, e.g. the collagen fibres are disorganised in that area.
It is very common in insertional Achilles tendonitis but can also develop in mid-portion tendonitis.
Treatment
Strange as it might sound, research suggests that the Achilles pain is usually not caused by the calcifications but rather by the tendinopathy. Many people without Achilles pain also have these calcifications in their tendons, and in our experience, people can recover fully from Achilles tendonitis despite still having the calcifications when you look at their scans.
In the vast majority of cases, people can recover fully if you treat them in the same way you treat Achilles tendonitis: reducing the strain on the injured area while you gradually rebuild the tendon’s strength.
💡 The main difference is that cases with calcifications are often a lot more painful at the start and easy to flare up, so the rehab process usually needs to be more gradual and take a bit longer.
You can find a detailed discussion of the best treatments for Achilles tendonitis here, because it should not be a one-size-fits-all approach. It might also be worth reviewing our advice on insertional Achilles tendonitis, since this is where these calcifications most commonly appear, and it can be more stubborn to treat.
Shockwave therapy might help to improve the symptoms of the tendonitis (but not too early in treatment), but it can’t break up this type of calcification or help your body to absorb it.
Corticosteroid injections should be left as a last resort, since it might worsen the collagen injury in the area of the tendonitis.
Surgery is not required in most cases, but it is an option if your pain does not respond to the treatment mentioned above. In addition to removing the calcifications, the surgeon will usually also remove the part of the tendon where the collagen fibres are injured.
Researchers found that the calcifications often return after surgery, despite the patient’s symptoms improving. This further supports the suspicion that the calcifications are likely not the reason for the pain.
2. Soft calcium deposits due to tendon cell change
This type is more common in older people, and is usually not linked to chronic tendinopathy but there are several case reports where surgeons found large quantities of soft calcium deposits accompanying tendon tears.
In this case, the calcium deposits play a key role in causing the tendon pain (but mostly just in the resorptive stage – see below) and can cause swelling and redness (typical signs of inflammation) in the affected area.
The deposits
In this case, some of the tendon cells themselves change from tendon cells to cartilage-type cells and start producing chalky soft deposits of calcium (carbonated hydroxyapatite); its consistency is a bit like that of toothpaste.
This is usually the process at play when someone is diagnosed with “calcific tendonitis”, although this term is often incorrectly used for other types of calcification.
Calcific Achilles tendonitis goes through five stages:
First some of the cells change from tendon cells to cartilage-type cells (precalcific stage).
Then the calcium deposits form (formative stage) – some patients report a dull ache during this stage, but it's also common not to feel any pain.
The calcium then just sits there for a while (resting stage).
At some point, the body notices it and sends clean-up cells and creates new blood vessels in the tendon to help remove it (resorptive stage),
Finally the tendon repairs with the correct type of cells.
Researchers are not sure why this happens, but several risk factors have been identified.
In a recent study, they looked at the foot and ankle X-rays of 433 people who had come to hospital (not necessarily for Achilles-related complaints). They found that 23.3% had calcific tendonitis in the Achilles tendons. But only 3% actually reported having Achilles pain. This is in line with a recent review study that reported that 30% to 50% of people who underwent CT scans for their shoulders had signs of calcific tendonitis, but without any symptoms.
👉 The researchers also found that that the following factors significantly increased your chances of getting calcific tendonitis:
older age
diabetes
hypercholesterolemia
hypothyroidism
a BMI of greater than 30 (obesity, in other words)
and patients with two or more of these factors had more than 10 times higher risk of developing calcific tendonitis.
It is also often caused by inflammatory arthritis, e.g. psoriasis and rheumatoid arthritis.
There’s still a debate among researchers as to whether statins (a medication taken to help lower cholesterol) might also increase the risk in some people – some studies show it might, while others show it has no effect or might even help recovery from tendon injuries.
What it looks like on scans
The calcification can show up differently on scans depending on in which stage it is – more ill-defined and translucent in the resorption phase for instance. Ultrasound scans seem to be best for diagnosing and classifying calcific tendonitis but it can show up on x-rays during certain stages. It can sometimes be missed on MRI scans.
It is often reported in the research that a defining characteristic of this type of calcification is that the tendon structure itself can look healthy and not show any signs of chronic tendonitis or tendinopathy on scans (there are exceptions). However, there might be extra blood vessels (neovascularization) in the tendon during the resorption stage, and as mentioned earlier, there are reports of them forming when a person has a tendon tear.
Treatment
What’s reassuring about this calcification process is that it can actually resolve without much issue or intervention. In most cases, the body will absorb the soft calcium deposits by itself, but the research is vague on how long this might take.
It is usually only when you enter the resorption stage that you start feeling pain – often quite a lot of pain! There is usually also quite a bit of inflammation present at this point, which is not the case with chronic tendinopathy. The evidence suggests that this very painful resorption stage lasts about two to three weeks.
When you’re in the very painful resorption stage, the best treatments are usually ones that help to calm the inflammation and irritation:
💊 anti-inflammatory medication
😴 relative rest – you don´t have to rest completely; just limit activities to what you can do without significantly increasing your symptoms
👟 simple hacks, like wearing shoes with higher heels can help to reduce the strain on the affected part of the Achilles tendon and help reduce pain
❌ strong exercises should be avoided during this period
Not all cases move spontaneously into the resorption stage which is why other treatments might also be useful.
Shockwave has been shown to help break up and resolve this type of calcification in shoulders – there isn’t any specific research into shockwave for calcific tendonitis in the Achilles tendon, but it might be something to try if yours is being stubborn.
Barbotage and Lavage are techniques (which are often combined) where the doctor will use a needle to puncture the soft calcium deposit, repeatedly stabbing it while injecting clean water to help dissolve it before drawing it out. This does seem to be effective and safe in shoulders – we don’t have any research (other than one case report) for the Achilles specifically. It is recommended in cases where conservative treatment of physiotherapy and anti-inflammatory medication has not helped. It is not recommended for very small calcifications (< 5 mm).
Corticosteroid injections might also help the very acute pain to settle and is often used in shoulders. However, this might not be a great option in the Achilles tendon, because it carries all your weight (unlike the shoulder), and these injections might increase your risk of rupturing your tendon. So it is best left for cases that do not want to respond to the other treatments mentioned.
In cases where patients' pain persists for more than six months and does not respond to the treatments listed above or where the calcium deposits are very large and remain hard, surgery can be a useful option.
Once the severe pain starts to settle, rehab exercises aimed at progressively strengthening the tendon can be started.
💡 Similar to when you’re recovering from regular Achilles tendonitis, it’s important that these exercises must match your Achilles’ current strength and sensitivity – if they’re too intense, they’ll just irritate your tendon and increase your symptoms.
You can find a detailed discussion of what a well-structured rehab plan for Achilles tendonitis looks like here.
3. Bony spurs (enthesophytes) at the insertion of the Achilles into the heel bone
The deposits
As the name suggests, bone spurs are made of actual bone and can even have bone marrow inside. (These should not be confused with Haglund’s Deformity, which is something different.)
We’ve included bone spurs in this article, because calcification forms part of the initial process of forming a bony spur, but it’s very different from the two types described above. It behaves like bone and cannot be absorbed by the body.
The area where your Achilles tendon attaches to your heel bone is called the enthesis, and you have some cartilage cells there. Sometimes, these cartilage cells start to create more bone in a specific area, which then creates the spur.
Bone spurs can develop without you ever having had an injury or inflammation in your Achilles tendon – it is thought to be triggered by excessive pulling of the tendon on the bone in that area.
💡 Interestingly, despite sounding painful, bone spurs on their own often don’t cause pain and are quite common in people who don’t complain of Achilles pain. In one study, researchers found bone spurs to be nearly as common in the heel that is not painful (55%) as in the heel that is painful (65%) of people with insertional Achilles tendonitis.
But insertional Achilles spurs do appear to be more common in patients with insertional Achilles tendonitis (65%-80%) than people without (25%-35%). This is not really surprising – both these conditions are caused by overuse and overworking the Achilles.
The spurs seem to be more a “symptom” or result of overuse (excessive pulling on the bone) rather than the main reason for Achilles pain or for why you develop Achilles tendonitis.
It is usually only if the tendon also develops Achilles tendonitis in that area that you start to feel pain, and that pain usually settles when the tendonitis is treated despite the spur remaining. However, if a bone spur breaks (fractures) or it becomes very large, it might also become a source of pain.
There’s no definitive consensus on what is seen as a “large” bone spur that definitely requires surgery. It appears that insertional Achilles tendonitis can be managed effectively without surgery even when accompanied by relatively large spurs (11 mm high and 6 mm wide).
What it looks like on scans
These show up as additional little bony points growing out of the heel bone in the lower part of the Achilles tendon, where it attaches into the heel bone.
Treatment
Since the main pain when you have a heel spur seems to be coming from the accompanying tendonitis, it should not surprise you that the same treatment that works for insertional Achilles tendonitis without bone spurs also works for the majority of cases where there is a bone spur.
You can find detailed information on what insertional Achilles tendonitis treatment entails here, but the most important aspect to help your pain settle quickly is to temporarily reduce how much the Achilles tendon pulls on the back of the heel bone. This can be achieved by:
👟 wearing shoes where the heel is higher than the front of the foot – clogs can be great if your heel doesn’t like shoes rubbing against it at the moment
❌ avoiding Achilles or calf stretches
👍 doing your calf raise exercises to floor level only as opposed to over the side of a step.
Surgery is an option in cases that don’t respond to conservative treatment.
How we can help
Need help with an 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
Maryke Louw is a chartered physiotherapist with more than 20 years' experience and a Master's Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.
