By Kimberly Koury, MD

What is Achilles Tendonitis?

Achilles tendinitis is a very common condition that occurs to the large tendon at the back of the heel that is formed from the calf muscle attaching to the heel bone. The Achilles tendon is the largest tendon in the body and helps you push off when you walk, run, jump and climb stairs.  It is the tendon that helps you stand up on your tippy toes.  Due to these high forces going through the tendon as well as blood supply concerns, it is prone to overuse and development of tendonitis.  Tendinitis is acute inflammation of the tendon and it can be associated with swelling, pain and irritation.  This is the body’s natural response to injury.  Sometimes the word tendinopathy is used when the condition has become more chronic in nature and the tendon actually may develop some microtears due to damage over time.  Typically the terms tendinitis, tendinosis or tendinopathy can be used interchangeably for the same problem.  These microtears and swelling that occurred are different from an acute Achilles tendon rupture/tearing from a sudden injury.

Types of Achilles Tendonitis

There are two types of commonly seen Achilles tendinitis which can be classified as insertional Achilles tendinitis or midsubstance Achilles tendinitis.  Mid substance Achilles tendinitis is the middle portion of the tendon approximately 6 cm above where it attaches at the bone of the heel.  This can lead to a focal area of thickening and tenderness.

Insertional Achilles tendinitis is used to describe inflammation of the tendon where it attaches to the heel bone (calcaneus).  This area is below the mid substance of the Achilles tendon.  This can be associated with an enlargement or bump on the back of the heel which is a bone spur from calcium developed within the Achilles tendon at the area of inflammation.  Both of these conditions can be associated with hardening and damage to the tendon fibers over time.

Causes of Achilles Tendonitis

Both of these conditions are frequently associated with calf muscle tightness which places stress on the Achilles tendon.  Causes of Achilles tendinitis are not always related to a specific injury.  It is more typically associated with overuse and repetitive stress on the tendon.  This could be due to sudden increase or change in activity, tightness of the calf muscles, and genetics or anatomic considerations.

Symptoms of Achilles Tendonitis

Common symptoms include pain in the Achilles.  This is more typical when you first get up in the morning or when sitting for long periods of time and then begin walking.  It tends to worsen with activity especially pushing off with running, jumping or inclines.  There can be associated thickening and swelling within the tendon as well as warmth and redness in the area that is affected.  You may be able to feel a bone spur at the back of the heel that rubs on shoes.

If you are experiencing the above symptoms, typically your doctor will get x-rays to evaluate for bone spurs and calcification within the tendon as well as overall bone structure of the heel and foot.  At times MRI may be indicated to evaluate the tendon in more detail.  This is not typically needed for a diagnosis.

If you have associated injury with a sudden pop or feeling like you got kicked in the back of the leg, this is a reason to seek immediate medical attention.

Treatment for Achilles Tendonitis

Treatment options include rest, ice and anti-inflammatories.  Stretching is a key component of keeping the tendon healthy and reducing the stress on the Achilles tendon. Typically, your doctor will provide calf stretching exercises and possible physical therapy. Bracing, shoe wear or orthotics may also be discussed.  Lastly, other non operative interventions may include acupuncture or extracorporeal shockwave therapy.

Steroid injections are not recommended for Achilles conditions given the increased risk of rupture or tearing of the tendon. More information is needed on other types of injections such as PRP which have not been fully studied.

Once nonoperative treatment options have been exhausted, there are sometimes surgical interventions which may provide significant relief.  This will typically include debridement of the diseased portions of the tendon and possible lengthening of the calf (gastrocnemius) muscle.

Results of Achilles tendinitis surgery are generally very positive with a reported return to presurgical activity up to 75% of patients with approximately 90% patient satisfaction rate. 

Achilles Tendinitis – OrthoInfo – AAOS. (n.d.). https://orthoinfo.aaos.org/en/diseases–conditions/achilles-tendinitis/