The Achilles tendon is the largest tendon in your body. It connects the upper calf muscles to the back of the heel bone. When the Achilles tendon degenerates and becomes inflamed, it is called Achilles tendinosis. 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).

For midsubstance Achilles tendinosis, surgery focuses on removing the diseased portion of the tendon. If most of the tendon is damaged, your foot and ankle orthopaedic surgeon often will use the tendon that goes to the big toe to support the Achilles tendon after repair. Other procedures may include lengthening the Achilles tendon or calf muscles if they are too tight.