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Overview

An Achilles tendon rupture is also known as a rupture of the gastrocnemius tendon, or the common calcanean tendon. The tendon is actually composed of 5 different tendons, the two most important being the superficial digital flexor and gastrocnemius tendons. The gastrocnemius tendon is the largest of these, and is the most powerful extensor of the hock (ankle) joint. Both the superficial digital flexor and gastrocnemius tendons attach to the heel bone, called the calcaneus bone. A rupture of the Achilles tendon may be a partial tear, which means just the gastrocnemius is torn, or a complete tear, in which all five tendons have been torn. (show diagrams, normal anatomy vs partial vs complete tears).

Causes
Inflammation/strain of the tendon is usually caused by overuse, for example, frequent jumping in volleyball, netball or basketball. It is often also caused by a sudden increase in certain types of training, such as hill sprinting or track running, particularly when running in spikes. Tendinopathy can also be associated with ageing. Our ability to regenerate damaged tissue decreases as we age and the quality of the tendon deteriorates. However, the better news is that sensible training can actually strengthen all our soft tissue (tendons, ligaments and muscle). Tightness in the calf muscles will demand greater flexibility of the tendon, which inevitably results in overuse and injury. Biomechanically, the tightness can reduce the range of dorsiflexion (toe up position) in the ankle, which increases the amount and duration of pronation. This problem is known as overpronation.* This reduces the ability of the foot to become a rigid lever at push off and places more lateral and linear forces through the tendon. This imbalance can translate into altered rotation of the tibia (shin bone) at the knee joint and, in turn, produce compensatory rotation at the hip joint with subsequent injuries to the shin, knee and hip. Pronation is part of the natural movement of the subtalar joint in the foot. It allows ?eversion? (turning the sole outwards), dorsiflexion and abduction (pointing the toes out to the side). Pronation is a normal part of the gait cycle, when walking and running, and it helps to provide shock absorption in the foot. When pronation is excessive, the foot has a tendency to roll inward more than normally acceptable. One sign of overpronation is greater wear on the inside of your running shoes than on the midsole. Lack of stability around the ankle joint can also be a contributory factor, as recurrent ankle sprains appear to be associated with a high incidence of Achilles tendonopathy. Wearing shoes that don?t fit or support the foot properly can be a major contributing cause of Achilles tendon injury.

Symptoms
Many people say that a ruptured Achilles feels like ?being shot in the heel?, if you can imagine how enjoyable that feels. You may hear a snap sound or feel a sudden sharp pain when the tendon tears. After a few moments, the pain settles and the back of the lower leg aches. You can walk and bear weight, but you may find it difficult to point the foot downward or push off the ground on the affected side. You will be unable to stand on tiptoe. Bruising and swelling are likely, and persistent pain will be present. Similar symptoms may be caused by an inflamed Achilles tendon (Achilles tendonitis), a torn calf muscle, arthritis of the ankle, or deep vein thrombosis in the calf, so an MRI or ultrasound scan will likely be used to diagnose your condition.

Diagnosis
It is usually possible to detect a complete rupture of the Achilles tendon on the history and examination. A gap may be felt in the tendon, usually 4-5cm above the heel bone. This is the normal site of injury and is called an intra-substance tear. The tear can occur higher up about 10cm above the insertion into the heel at the site where the muscles join the tendon, this is known as a musculo-tendinous tear. A special test will be performed which involves squeezing the calf. Normally if the Achilles tendon is intact this causes the foot to point downwards but if it is ruptured it causes no movement. To confirm the diagnosis and the exact site of the rupture it may be necessary to perform an Ultra-sound or MRI scan.

Non Surgical Treatment
Non-surgical treatment typically involves wearing a brace or cast for the first six weeks following the injury to allow time for the ends of the torn tendon to reattach on their own. Over-the-counter medications, such as ibuprofen or aspirin, may be taken during this time to reduce pain and swelling. Once the tendon has reattached, physical therapy will be needed to strengthen the muscles and tendon. A full recovery is usually made within four to six months.


Surgical Treatment
Surgery could allow for a quicker healing time. The procedure generally involves making an incision in the back of your lower leg and stitching the torn tendon together. Depending on the condition of the tissue, the repair may be reinforced with other tendons. As with any surgery, the main complication is the risk for infection, however, this risk is reduced by using smaller incisions.

Prevention
Prevention centers on appropriate daily Achilles stretching and pre-activity warm-up. Maintain a continuous level of activity in your sport or work up gradually to full participation if you have been out of the sport for a period of time. Good overall muscle conditioning helps maintain a healthy tendon.