The Mighty Achilles

  • March 11, 2021
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  • Ankle & Foot
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  • Dr. Tony Mechrefe       

One of the most common reasons for patients to present to my office is for Achilles tendon problems. The Achilles tendon is the strongest tendon in the human body, capable of propelling the human body into running, jumping and explosive activities that are often capable of handling three to four times body weight. As such, the Achilles tendon is under a tremendous amount of stress and is able to handle this often without much issue. However, Achilles problems can be incredibly disabling, and range from simple Achilles’ tendonitis to Achilles tendinopathy and ultimately Achilles’ tendon ruptures. The reason the Achilles is susceptible to these problems is secondary to overuse, genetics, and anatomy.

The anatomy of the Achilles is such that its muscular origin lies in both the gastrocnemius and soleus muscles (calf muscles). These two muscles then travel down the leg and form, by their melding together, the Achilles tendon. While these two muscle bellies are very robust and full of great blood supply, once the Achilles tendon forms, it is a rather avascular tissue (not much blood flow). If you are just to reach down and feel your own Achilles tendon, there's nothing but skin and Achilles, without much other supporting soft tissues, namely muscle which provides healthy blood flow, crucial to tissue health. This lack of blood flow sets up the Achilles tendon for potential injury.

The simplest problem of the Achilles come from overuse…Achilles tendonitis. Tendonitis of the Achilles tendon really has to do with the paratenon, which is a thin layer of tissue that surrounds the Achilles tendon. Fluid that accumulates around the Achilles stretches this outer covering of the Achilles and causes pain. This is often managed very successfully with a period of rest, stretching, ice, anti-inflammatory and sometimes physical therapy to eradicate the problem.

The next Achilles problem in rising order of complexity is Achilles tendinopathy. Achilles tendinopathy has to do with the body's preprogramed genetics for type 2 collagen to crosslink in the body. Huh?  Crosslinking is the natural process of aging of collagen fibers, and when this happens to the Achilles tendon fibers, it causes them to be rather brittle. Imagine opening up a fresh bag of rubber bands and bunching them all together and stretching them. The natural spring of these rubber bands represents the natural spring of the Achilles tendon. Every rubber band represents one of the thousands of single fibers of tendon tissue that make up an Achilles tendon. Now pretend you place those rubber bands in a drawer, and then remove them 30 years from now. As you bunch up those rubber bands, you'll notice that some of them are cracked, they’re drying out, and they just don't have that same elasticity. This is what happens to the human Achilles tendon as it ages. As these fibers crack, the body tries to heal it by bringing in fibrous tissue. Every cracked fiber that heals causes the Achilles to become thicker and thicker. Patients with Achilles tendinopathy will often complain of a thick and swollen painful tendon. Unfortunately, this disease process is not reversible however it is easily treated. Mechanical stretching with bracing and physical therapy can help restore some of this natural elasticity, and as such, alleviate much of the symptoms that people with Achilles tendinopathy suffer from. When this is not successful, and if it is significantly limiting to a patient, surgical reconstruction can be considered. These operations are incredibly successful at restoring function and alleviating pain.

Finally, Achilles tendon ruptures represent the worst possible morbidity that can be associated with the Achilles tendon. In my career of treating upwards of 1000 Achilles tendon ruptures. The history that patients give is almost universal, in that patients all complain that they feel like someone either hit them from behind, stepped on them from behind, or struck an object into them from behind. Achilles tendon ruptures leave the patient with significant weakness to push off of the Achilles, that can cause significant disability, particularly in the young active person. While there's been some controversial literature regarding surgical versus nonsurgical management, the mainstay for treatment of acute Achilles tendon ruptures in the healthy active individual is surgical repair. This often can be done through minimally invasive techniques that leave the patient with very small scars, low risk of infection, and quick return to function and activity. In patients that are not good surgical candidates - patients with multiple medical problems, and patients with low demand lifestyles - non-surgical management can be very successful with casts and/or walking boots.

At the end of the day, the take home message with the mighty Achilles is to listen to your body. The Achilles tendon is very good at warning you when it's time to take it easy. This is one of those body parts where I remind patients that the adage, “no pain is no gain”, does not work. If your body is giving you pain in the Achilles, it's telling you its time to slow down.


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  • Ankle