A tendon is a band of tissue that connects a muscle to a bone. The Achilles tendon runs down the back of the lower leg and connects the calf muscle to the heel bone. Also called the "heel cord," the Achilles tendon facilitates walking by helping to raise the heel off the ground. An Achilles tendon rupture is a complete or partial tear that occurs when the tendon is stretched beyond its capacity. Forceful jumping or pivoting, or sudden accelerations of running, can overstretch the tendon and cause a tear. An injury to the tendon can also result from falling or tripping. Achilles tendon ruptures are most often seen in "weekend warriors", typically, middle-aged people participating in sports in their spare time. Less commonly, illness or medications, such as steroids or certain antibiotics, may weaken the tendon and contribute to ruptures.
An Achilles tendon rupture is often caused by overstretching the tendon. This typically occurs during intense physical activity, such as running or playing basketball. Pushing off from the foot while the knee is straight, pivoting, jumping, and running are all movements that can overstretch the Achilles tendon and cause it to rupture. A rupture can also occur as the result of trauma that causes an over-stretching of the tendon, such as suddenly tripping or falling from a significant height. The Achilles tendon is particularly susceptible to injury if it is already weak. Therefore, individuals who have a history of tendinitis or tendinosis are more prone to a tendon rupture. Similarly, individuals who have arthritis and overcompensate for their joint pain by putting more stress on the Achilles tendon may also be more susceptible to an Achilles tendon rupture.
The most common initial symptom of Achilles tendon rupture is a sudden snap at the back of the heels with intense pain. Immediately after the rupture, the majority of individuals will have difficult walking. Some individuals may have had previous complains of calf or heel pain, suggesting prior tendon inflammation or irritation. Immediately after an Achilles tendon rupture, most individuals will develop a limp. In addition, when the ankle is moved, the patient will complain of pain. In all cases, the affected ankle will have no strength. Once the Achilles tendon is ruptured, the individual will not be able to run, climb up the stairs, or stand on his toes. The ruptured Achilles tendon prevents the power from the calf muscles to move the heel. Whenever the diagnosis is missed, the recovery is often prolonged. Bruising and swelling around the calf and ankle occur. Achilles tendon rupture is frequent in elderly individuals who have a sedentary lifestyle and suddenly become active. In these individuals, the tendon is not strong and the muscles are deconditioned, making recovery more difficult. Achilles tendon rupture has been reported after injection of corticosteroids around the heel bone or attachment of the tendon. The fluoroquinolone class of antibiotics (such as ciprofloxacin [Cipro]) is also known to cause Achilles tendon weakness and rupture, especially in young children. Some individuals have had a prior ten