Achilles tendinosis is often confused with Achilles tendonitis, which is acute (sudden onset) inflammation of the tendon. Distinguishing these conditions is important to ensure proper treatment.
Inflammation vs. Degeneration
Tendonitis and tendinosis have some overlapping features, as well as important differences. They are both caused by short-term or long-term trauma or overuse, but tendinitis is usually more inflammatory, while tendinosis is a type of damage.
And sometimes, if recurrent or sudden trauma causes tendon damage and inflammation, you can have both.
Achilles Tendonitis
Achilles tendonitis is most often caused by repetitive overuse and not a singular one-time event. Symptoms may appear suddenly during activity even when the cause is due to overuse.
Achilles tendonitis is acute inflammation of the Achilles tendon. “Acute” inflammation means that the inflammation is active. This kind of inflammation involves redness, warmth, pain, and swelling.
Another common symptom of Achilles tendonitis is called crepitus. Crepitus is a grinding sensation and popping sound that can be felt and heard by placing your hand over a moving tendon. The inflammation and swelling of the tendon cause a grinding sensation that can be felt by your hand.
On a microscopic level, specific cells can be seen in inflammatory conditions—your body brings these cells to the affected area in order to manage inflammation and heal the injured tendon. With Achilles tendonitis, there is no underlying permanent change In the tendon.
Achilles Tendinosis
Achilles tendinosis is a thickening of the tendon. It causes pain, but there is typically no warmth or redness surrounding the soft tissues,
Achilles tendinosis is a chronic problem. This means that it is a long-term condition that develops over time. Microscopically, very small tears of the tendon may be seen along with chronic damage.
It is not characterized by inflammation, and inflammatory cells would not typically be seen on a microscopic level with this condition.
This condition is diagnosed based on symptoms. An X-ray of the ankle joint might be normal, although it is possible to see small calcific deposits or bone spurs around the tendon. These are signs of chronic inflammation. An MRI test may show microscopic tearing or degeneration of the tendon tissue, as well as thickening of the damaged portion of the tendon.
Treatment
While the treatment of Achilles tendonitis and Achilles tendinosis are similar, they are not always the same.
The more effective treatments for Achilles tendinosis tend to be shoe inserts, therapeutic exercises, and stretching.
Exercises that focus on the eccentric contraction of the Achilles tendon have been shown to be the most effective way to stimulate healing of the damaged portion of the tendon. Eccentric contractions are performed by contracting the muscle-tendon unit, while also providing a lengthening force. For example, doing toe dips, and slowly dipping down is an effective eccentric exercise for the Achilles tendon.
Medication
Modalities aimed to reduce inflammation (ice, anti-inflammatory medications) will likely do very little to help resolve Achilles tendinosis. Anti-inflammatory medications (NSAIDs) and ice applications may be used to treat symptoms of discomfort associated with Achilles tendinosis, but they don’t treat the underlying problem.
Achilles tendonitis is treated with therapies that reduce inflammation.
Surgery
Your surgeon may recommend surgical treatment of the damaged tendon. In these cases, most often the damaged portion of the tendon is surgically removed. Once the abnormal tendon is removed, the surrounding tendon can be repaired around the defect.
If too much of the tendon is damaged and has to be removed, your surgeon may transfer a nearby tendon to the repaired Achilles to help it function normally. This is called a tendon transfer.
A Word From Verywell
Achilles tendon problems may differ in their cause, symptoms, and treatment. One important distinction is to determine if the cause of the problem is inflammation or chronic degeneration. Achilles tendinosis is a problem that results from chronic breakdown and deterioration of the tendon tissue. Unlike an inflammatory problem, Achilles tendinosis tends to respond much better to therapeutic treatments rather than treatments to reduce inflammation. This is why it is critical to determine the source of your Achilles pain, rather than just the location.
