The Achilles tendon is the thick tendon formed by the two muscles of the calf: the gastrocnemius and the soleus. These two muscles function in plantar flexing the ankle. This is the motion that occurs when you rise up on to your toes. The Achilles tendon is located on the back of the ankle and functions in attaching these muscles to the calcaneous or heel bone.
Cause of Tendon Rupture
Because this tendon is used with all walking, running, and jumping activity, injury to the tendon is not uncommon. The most common injury secondary to overuse of the tendon is Achilles Tendonitis. Achilles tendon ruptures can occur after prolonged bouts of tendonitis symptoms. Tendonitis results in stiff and inflexible tendon tissue. In some cases of Achilles tendonitis, micro tears can occur, leading to the weakening of the tissue. Lack of tissue flexibility and tissue weakening (such as tissue weakening associated with cortisone injections) can lead to increased risk of tendon rupture.
Achilles tendon ruptures generally occur with some type of explosive activity. A common mechanism of injury involves an aggressive push off on the toes such as going for a ball when playing tennis or jumping up for a lay-up while playing basketball. This explosive demand on the tendon is too great with the result being tendon rupture.
Tendon Rupture Signs and Symptoms
When an acute Achilles tendon rupture occurs, the most common symptom is the feeling as if someone kicked you in the back of the leg. The leg simply gives way, often a ‘pop’ is felt, and the ability to push off of the foot is lost. You may still be able to walk and even plantar flex your foot but generally you will walk with a limp. Often swelling will occur immediately.
In some cases the calf muscle will feel like a big ball as the tendon and muscle bunches up. Similar to when a shade is pulled down and then released, when complete rupture occurs the tendon and calf muscle is released and moves up toward the knee.
Diagnosis of an Achilles rupture will be made with both physical exam and a MRI. During the physical exam of your leg, the doctor will perform the Thompson test by squeezing the calf muscle. A normal response is for the foot to plantar flex or the foot to point down. If there is no movement, the test is positive for a tendon rupture. If this test is positive, an MRI will often be recommended to confirm the extent of Achilles damage.
The decision as to whether or not you will need Achilles tendon surgery will be based in part on the extent of the injury. Other factors include age, activity level, ability to heal, and the quality of the tendon tissue.
A partial tear of the tendon may not require surgery. Rather, an immobilizer will be worn for an extended period of time, allowing the tendon to scar. Frequently the foot will be placed in a plantar flexed or toe down position in order to minimize the stretch on the Achilles. Generally while the tendon heals, you will not be allowed to apply weight on your foot. Healing will take a minimum of six weeks with physical therapy for recovery to follow.
For most, if the tendon is completely ruptured, surgery is the best option. Surgery involves suturing the ends of the Achilles tendon back together.
It is important to note that it is recommend the surgery be performed within a few weeks following injury. Over time the tissue begins to shorten, making it more difficult to reconnect the tendon. If you think you have a significant Achilles injury, seeking medical attention quickly is advised.