The Achilles tendon is the largest tendon in the human body. It connects the calf muscle to the heel bone. However, this tendon is also the most common site of rupture or tendonitis, an inflammation of the tendon due to overuse. Achilles tendon rupture is a partial or complete tear of the Achilles tendon. It comes on suddenly, sometimes with a popping sound, and can be debilitating. A full rupture is more severe, but less common, than a partial rupture. A full rupture splits the Achilles tendon so that it no longer connects the calf muscle to the heel: the calf muscle can no longer cause the foot to ?push off?, so normal walking is impossible. If it is a full rupture, then lightly pinching the Achilles tendon with the forefinger and thumb will reveal a gap in the Achilles tendon. Partial and full Achilles tendon ruptures are most likely to occur in sports requiring sudden stretching, such as sprinting and racquet sports. Partial Achilles tendon tears are also common among middle and long distance runners.Causes
There are a number of factors that can increase the risk of an Achilles tendon rupture, which include the following. You?re most likely to rupture your Achilles tendon during sports that involve bursts of jumping, pivoting and running, such as football or tennis. Your Achilles tendon becomes less flexible and less able to absorb repeated stresses, for example of running, as you get older. Small tears can develop in the fibres of the tendon and it may eventually completely tear. There is a very small risk of an Achilles tendon rupture if you have Achilles tendinopathy (also called Achilles tendinitis). This is where your tendon breaks down, which causes pain and stiffness in your Achilles tendon, both when you exercise and afterwards. If you take quinolone antibiotics and corticosteroid medicines, it can increase your risk of an Achilles tendon injury, particularly if you take them together. The exact reasons for this aren't fully understood at present.
Symptoms
An Achilles tendon rupture is when the tendon that connects the heel bone to the calf muscle tears and the fibers separate. This happens mostly between the ages of 30 and 50, and usually is caused by sports. Symptoms of Achilles tendon rupture include the following. A pop or snap when the tendon tears. Severe pain in back of the ankle, making it nearly impossible to walk. Swelling and discoloration. Tenderness. Inability to rise on toes. A gap in the back of the ankle where the tendons are separated.
Diagnosis
A typical history as detailed above together with positive clinical examination usually will clinch the diagnosis. In an acute rupture, one can usually feel the gap in the tendon from the rupture. There may be swelling or bruising around the ankle and foot of the injured leg. With the patient lying on the tummy (prone position) with the knee flexed, the examiner should see the ankle and foot flex downwards (plantarward) when squeezing the calf muscles. If there is no movement in the ankle and foot on squeezing the calf muscle, this implies that the calf muscle is no longer attached to the heel bone due to a complete Achilles tendon rupture.
Non Surgical Treatment
Medical therapy for a patient with an Achilles tendon rupture consists of rest, pain control, serial casting, and rehabilitation to maximize function. Ongoing debate surrounds the issue of whether medical or surgical therapy is more appropriate for this injury. Conservative management of Achilles tendinosis and paratenonitis includes the following. Physical therapy. Eccentric exercises are the cornerstone of strengthening treatment, with most patients achieving 60-90% pain relief. Orthotic therapy in Achilles tendinosis consists of the use of heel lifts. Nonsteroidal anti-inflammatory drugs (NSAIDs). Tendinosis tends to be less responsive than paratenonitis to NSAIDs. Steroid injections. Although these provide short-term relief of painful symptoms, there is concern that they can weaken the tendon, leading to rupture. Vessel sclerosis. Platelet-rich plasma injections. Nitric oxide. Shock-wave therapy.

Surgical Treatment
Surgery is recommended to those who are young to middle-aged and active. The ruptured tendon is sewn together during surgery. This is an outpatient procedure. Afterward the leg is put into a splint cast or walking boot. Physical therapy will be recommended. In about 4 to 6 months, healing is nearly complete. However, it can take up to a year to return to sports fully.
Prevention
The best treatment of Achilles tendonitis is prevention. Stretching the Achilles tendon before exercise, even at the start of the day, will help to maintain ankle flexibility. Problems with foot mechanics can also lead to Achilles tendonitis. This can often be treated with devices inserted into the shoes such as heel cups, arch supports, and custom orthotics.