Achilles Tendon Tears: Overview

Achilles Tendon Tears: Overview

The Achilles tendon is the largest and strongest tendon in the human body, found at the back of the lower leg. It allows us to actively point our toes and provide strength when pushing off of our feet during activities like running, jumping, and walking. However, the Achilles tendon can rupture, meaning the tendon tears and the ends of the tendon fibers separate from one another, resulting in the loss of these functions.

Conditions of the Achilles tendon, including both tears and chronic inflammation, affect 250,000 people per year in the United States, with 6% of the general population reporting Achilles pain in their lifetime. Most Achilles tendon ruptures occur during a sporting activity, although it can also result from long-standing Achilles tendon inflammation. Other factors that may increase the risk of sustaining an Achilles tendon rupture include but are not limited to, male sex, obesity, smoking, improper footwear, overtraining, and use of certain medications.

Ruptures of the Achilles tendon result from a sudden, forceful contraction of the calf muscle. This can happen in two ways. The first occurs with the knee straight with a sudden forceful push-off that leads to pointing of the toes, referred to as plantar flexion. The second results from the sudden flexing of the foot upward, referred to as dorsiflexion on an already tensioned calf muscle.

How can you take steps to prevent an Achilles tendon tear? Incorporating a dynamic warm-up prior to physical activity is important. It is also beneficial to work on single-leg strengthening of your calf muscles so one side does not become more dominant than the other. When starting a new activity, it is advised to slowly ramp up the intensity as opposed to a quick increase. Lastly, ensuring you are wearing proper footwear can also help.

Let us take a closer look at the anatomy. The Achilles tendon is located at the back of the lower leg. Just above the tendon, we see the gastrocnemius muscle located closer to the skin surface, collectively, the gastrocnemius, or gastroc for short, and soleus are referred to as the calf. These muscles give rise to the Achilles tendon, which runs down the leg and attaches to the back of the heel bone, known as the calcaneus. The Achilles tendon is approximately 15 cm in length. Acute ruptures of the tendon typically occur 4 to 6 cm above the insertion on the heel bone, referred to as a midsubstance rupture. Decreased blood supply to this area of the tendon leads to the increased risk of tendon rupture at this location.

When a patient sustains an Achilles tendon tear, followed by onset of pain, and often report an audible pop. After injury, patients find it difficult to walk, and if the tear is complete, they are unable to point their toes. When seeing a health care professional after sustaining an Achilles tendon tear, they will perform a physical examination. They will inspect the back of the lower leg, looking for signs of bruising and swelling. They will feel the Achilles tendon itself for any defects in the tendon fibers. In addition, the doctor will check to see if the patient can point and flex their toes.

Often, the diagnosis of an Achilles tendon tear is made based on the injury mechanism and the physical examination alone. However, additional imaging studies, such as an x-ray or MRI, can be used to rule out other conditions of the ankle. Sometimes, the Achilles only tears partially, as opposed to completely rupturing into two separate ends. In that case, a surgeon may order additional testing with an MRI to help determine the most appropriate treatment plan. After a thorough evaluation, the surgeon will take many factors into consideration, and discuss the appropriate options for treatment with the patient.