What is Achilles Tendinitis?

The Achilles tendon is the largest tendon in the body. It connects the upper calf muscles to the back of the heel bone. Achilles tendinitis is an injury to this tendon that causes pain in the back of the leg. Typically this injury results from inflammation of the surrounding sheath (paratenonitis), degeneration within the tendon (tendinosis), or a combination of the two.


Paratenonitis is more typical in younger people. Symptoms start gradually and spontaneously. You may experience aching and burning pain, especially with morning activity, that gets worse with exercise.

Tendinosis feels similar but is more typical in middle-aged people. If you have severe pain and difficulty walking, it may indicate a partial tear of the tendon.


The cause of paratenonitis is not well understood although it is common in people who have recently increased the intensity of running or jumping workouts. It can be associated with repetitive activities, problems such as flatfoot or high-arched feet, or running on slanted surfaces or uneven/hard ground. Tendinosis can occur as you age.


Your tendon may feel enlarged and warm 1-4 inches above your heel. Gently squeezing the tendon between your thumb and forefinger while you move your ankle may cause pain and sometimes a scratching feeling. You may have weakness in push-off strength with walking.

A foot and ankle orthopaedic surgeon will evaluate your symptoms and history to make a diagnosis. An MRI may be used to define the extent of the degeneration, the degree to which the tendon sheath is involved, and the presence of other problems in this area.


Non-surgical Treatment

Most cases are successfully treated non-surgically with nonsteroidal anti-inflammatory medications, rest, immobilization, limitation of activity, ice, contrast baths, stretching, and/or heel lifts. It takes time for symptoms to improve, which may be frustrating if you are used to being active. Treatment is less likely to be successful if symptoms have been present for more than six months.

If you still experience symptoms, your surgeon may recommend a formal physical therapy program, or a cast or brace to completely rest the area. An arch support may help if you also have flatfoot. Extracorporeal shock wave therapy and platelet-rich plasma injections may be explored as well.

Surgical Treatment

Brisement is another option for paratenonitis. In this procedure, local anesthetic is injected into the space between the tendon and its surrounding sheath to break up scar tissue. This can be beneficial in the earlier stages of Achilles tendinitis, but may need to be repeated 2 or 3 times. This technique is not used for tendinosis.

If non-surgical treatments do not help, surgery may be considered. Surgery consists of cutting out the surrounding thickened and scarred sheath and repairing any tears within the tendon. You will be asked to move your leg almost immediately to prevent repeat scarring of the tendon. Your surgeon will advise when you can put weight on your leg. Return to competitive activity takes 3-6 months.

Surgery for tendinosis involves removing scar tissue and calcification deposits in the tendon. The tendon is then repaired with suture. In older patients, or when more than half of the tendon is removed, one of the other tendons at the back of the ankle is transferred to the heel bone to improve the strength of the Achilles tendon and the blood supply to this area. 


It may take up to two years for symptoms to go away completely. At least 3-6 months of non-surgical treatment is recommended before considering surgery. You will need to wear a cast, splint, or brace for 4-8 weeks following surgery, although you will start doing range-of-motion exercises before that.

Non-surgical management of paratenonitis may take several months but patients return to pre-injury activities in 90% of cases. For the other 10%, subsequent surgical treatment is successful in 75-100% of cases. 

Recovery from non-surgical and surgical treatment for tendinosis is less predictable. Your age, the extent of your injury, the amount of time you experienced symptoms, and whether a tendon transfer was performed can affect the surgery’s success. 

Risks and Complications

The risk of Achilles tendon rupture is small but present. You should not return to normal running and jumping athletic activities until the pain is gone and the area is no longer tender to touch. Please check with your foot and ankle orthopaedic surgeon before returning to activities. As with any surgery, there are risks of infection and wound problems, although these are uncommon.

Would a cortisone injection help?

Cortisone injections are not recommended for the treatment of Achilles tendinitis because they can weaken the tendon and make it much easier to rupture.


Contributors/Reviewers: Sudheer Reddy, MD; David Garras, MD

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