Overview 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 Often an Achilles rupture can occur spontaneously without any prodromal symptoms. Unfortunately the first "pop" or "snap" that you experience is your Achilles tendon rupture. Achilles tendon rupture most commonly occurs in the middle-aged male athlete (the weekend warrior who is engaging in a pickup game of basketball, for example). Injury often occurs during recreational sports that require bursts of jumping, pivoting, and running. Most often these are tennis, racquetball, squash, basketball, soccer, softball and badminton. Achilles rupture can happen in the following situations. You make a forceful push-off with your foot while your knee is straightened by the powerful thigh muscles. One example might be starting a foot race or jumping. You suddenly trip or stumble, and your foot is thrust in front to break a fall, forcefully over stretching the tendon. You fall from a significant height. It does appear that previous history of Achilles tendonitis results in a degenerative tendon, which can grow weak and thin with age and lack of use. Then it becomes prone to injury or rupture. Certain illnesses (such as arthritis and diabetes) and medications (such as corticosteroids and some antibiotics) can also increase the risk of rupture. Symptoms A sudden and severe pain may be felt at the back of the ankle or calf, often described as "being hit by a rock or shot" or "like someone stepped onto the back of my ankle." The sound of a loud pop or snap may be reported. A gap or depression may be felt and seen in the tendon about 2 inches above the heel bone. Initial pain, swelling, and stiffness may be followed by bruising and weakness. The pain may decrease quickly, and smaller tendons may retain the ability to point the toes. Without the Achilles tendon, though, this would be very difficult. Standing on tiptoe and pushing off when walking will be impossible. A complete tear is more common than a partial tear. Diagnosis The diagnosis of an Achilles tendon rupture is made entirely on physical examination. Often, there is a substantial defect in the Achilles from 2-5 cm before it inserts into the heel bone. However, the main test is to determine whether the Achilles has been ruptured is the Thompson test. This essentially involves placing the patient on their stomach and squeezing the calf muscle. If the Achilles is intact, the foot will rise [plantar flex]. If it is ruptured, the foot will not move and will tend to be in a lower lying position. Non Surgical Treatment Once a diagnosis of Achilles tendon rupture has been confirmed, a referral to an orthopaedic specialist for treatment will be recommended. Treatment for an Achilles tendon rupture aims to facilitate the torn ends of the tendon healing back together again. Treatment may be non-surgical (conservative) or surgical. Factors such as the site and extent of the rupture, the time since the rupture occurred and the preferences of the specialist and patient will be considered when deciding which treatment will be undertaken. Some cases of rupture that have not responded well to non-surgical treatment may require surgery at a later stage. The doctor will immobilise the ankle in a cast or a special hinged splint (known as a ?moon boot?) with the foot in a toes-pointed position. The cast or splint will stay in place for 6 - 8 weeks. The cast will be checked and may be changed during this time. Surgical Treatment Surgery may be indicated directly following injury rather than conservative care. Repair of an achilles tendon rupture is greatly varied for each clinical situation. There may be a direct repair of the ends of the tendon with suture, or possibly a tendon graft used to augment the tendon. Post-operatively, the period of immobilization will depend on the size of the defect that was repaired and how it was completed. Usually the immobilization is between 6-10 weeks. This repair may allow for a complete return to normal function, but in many instances the healing is complicated with adhesions and a partial loss of range of motion. There may be a continued soft tissue defect noted and a permanent or prolonged swelling. Prevention Achilles tendon rupture can be prevented by avoiding chronic injury to the Achilles tendon (i.e. tendonitis), as well as being careful to warm up and stretch properly before physical activity. Additionally, be sure to use properly fitting equipment (e.g. running shoes) and correct training techniques to avoid this problem!