When the Achilles tendon degenerates and become inflamed, the condition is called Achilles tendinosis. The tendon can swell and may cause pain. This condition is common in athletes, runners and patients who have calf tightness. Achilles tendinosis may occur in the middle of the tendon. This is known as midsubstance Achilles tendinosis. It may also occur at the point where the tendon connects to the heel bone. This is known as insertional Achilles tendinosis.

Many changes can be seen when the Achilles tendon becomes inflamed. 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. Patients may have difficulty climbing stairs or running. Patients may also have pain after sitting for long periods or after sleeping. Many patients will notice a bump either in the tendon (midsubstance Achilles tendinosis) or right behind the heel bone (insertional Achilles tendinosis). Some may also get irritation from shoes rubbing against the bump and feel better when wearing backless shoes. Patients also commonly have less pain while wearing a shoe with a slight heel versus shoes that are flat.

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

A thorough history is taken and an examination is performed. Patients will usually have pain right on the tendon or at the back of the heel. They may also 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 also be performed to further evaluate how much of the tendon is affected and to look for any tears.