What is achilles tendinosis?

Achilles Tendon

The Achilles tendon is the largest tendon in your body. It connects the upper calf muscles to the back of the heel bone. Achilles tendinosis is a condition in which the Achilles tendon degenerates and becomes inflamed. Sometimes, it may also be called Achilles tendinitis. If you have Achilles tendinosis, your tendon can swell and become painful. This condition is common in athletes, runners, and people who have calf tightness. Achilles tendinosis may occur in the middle of the tendon (known as midsubstance Achilles tendinosis) or at the point where the tendon connects to the heel bone (known as insertional Achilles tendinosis).


You may see many changes when the Achilles tendon becomes inflamed. Many patients have pain and/or tightness in the tendon behind the ankle. Most of the time there is no trauma or injury, but rather a slow progression of pain. You may have difficulty climbing stairs or running. You also may have pain after sitting for long periods or after sleeping. Many patients notice a bump either in the tendon or right behind the heel bone. Some also get irritation from shoes rubbing against the bump and feel better when wearing backless shoes. Patients commonly have less pain while wearing a shoe with a low heel versus shoes that are flat.


Achilles and calf tightness are common causes of Achilles tendinosis. In addition, insertional Achilles tendinosis often is associated with a heel bone spur. This spur may rub against the Achilles tendon and lead to small tears. It is similar to a rope being rubbed against a sharp rock. This is also known as Haglund’s deformity. Pain and swelling occur as the cumulative effects of chronic wear and tear on the tendon.


Your foot and ankle orthopedic surgeon will take a thorough history and perform an examination. It is common to have pain right on the tendon or at the back of the heel. You also may have swelling and thickening of the tendon. X-rays may be taken to see if there are any bone spurs. An MRI or ultrasound may be ordered to look for tears and further evaluate how much of the tendon is affected.


Treatment depends on the length and severity of the symptoms. Many patients improve without surgery. Rest and oral medications may help reduce the swelling and pain. Heel cups can improve pain by taking some of the stress off of the Achilles tendon when walking. A walking boot or other brace may be recommended.

Often, formal physical therapy is recommended to work on stretching and improve mobility within the calf muscle. Other treatments may include ultrasound, massage, shockwave therapy, and topical nitroglycerin patches. Recently, platelet-rich plasma has been discussed as a treatment for Achilles tendinosis. This involves taking one’s own blood and isolating growth factors that are involved in healing. This serum is then injected into the inflamed tendon.

In some cases, surgery may be required. The specifics of the surgery depend upon the location and extent of the tendinosis.


If I am treated without surgery for Achilles tendinosis will it come back?

While most patients will achieve lasting relief after treatment for Achilles tendinosis, symptoms may return. The risk decreases if the patient continues to do routine stretching even after the symptoms go away. However, athletes and runners in particular are at a slightly higher risk for this condition because of the high demands they put on the Achilles. These patients should pay close attention to stretching and shoe choice to prevent chronic recurrence.

What are the outcomes for those who have surgery for Achilles tendinosis?

Surgery can predictably return patients to activity. Success rates for Achilles tendinosis surgery are 80-90 percent. Some of the variability depends on the amount of tendon that is diseased at the time of surgery.

Patients improve with both conservative and operative management of Achilles tendinosis. Physical therapy has been shown to help most patients with this condition and should be tried before surgery is considered.