The Achilles tendon is the confluence of the independent tendons of the gastrocnemius and soleus, which fuse to become the Achilles tendon approximately 5 to 6 cm proximal to its insertion on the posterior surface of the calcaneus. The gastrocnemius and soleus muscles, via the Achilles tendon, function as the chief plantarflexors of the ankle joint. This musculotendinous unit provides the primary propulsive force for walking, running, and jumping. The normal Achilles tendon can withstand repetitive loads near its ultimate tensile strength, which approach 6 to 8 times body weight.
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.
Typically patients present with sudden onset of pain and swelling in the achilles region, often accompanied by a audible snap during forceful dorsiflexion of the foot. A classic example is that of an unfit 'weekend warrior' playing squash. If complete a defect may be felt and the patient will have only minimal plantar flexion against resistance.
In diagnosing an Achilles tendon rupture, the foot and ankle surgeon will ask questions about how and when the injury occurred and whether the patient has previously injured the tendon or experienced similar symptoms. The surgeon will examine the foot and ankle, feeling for a defect in the tendon that suggests a tear. Range of motion and muscle strength will be evaluated and compared to the uninjured foot and ankle. If the Achilles tendon is ruptured, the patient will have less strength in pushing down (as on a gas pedal) and will have difficulty rising on the toes. The diagnosis of an Achilles tendon rupture is typically straightforward and can be made through this type of examination. In some cases, however, the surgeon may order an MRI or other advanced imaging tests.
Non Surgical Treatment
Treatment of a ruptured Achilles tendon is usually conservative (non-operative) in a Controlled Motion Ankle (CAM) Boot or it may require surgery. The current consensus based on research is to treat them conservatively since the functional outcome and chance of re-rupture is similar (7% to 15%) using both approaches but surgical intervention has a higher risk of infection. Achilles tendon surgery is usually considered if your Achilles has re-ruptured or there is delay of two weeks between the rupture and the diagnosis and commencement of conservative bracing and treatment.
Surgery to repair an Achilles tendon rupture is performed under a spinal or general anaesthetic. During surgery the surgeon makes an incision in the skin over the ruptured portion of the tendon. The tendon ends are located and joined together with strong sutures (stitches), allowing the tendon to closely approximate its previous length. The skin is then closed with sutures and the foot is immobilised in a cast or splint, again in the toes-pointed position. Seven to ten days after surgery the cast or splint is removed in order for the sutures in the skin to be removed. Another cast or splint will be applied and will stay in place a further 5 - 7 weeks.
To help prevent an Achilles tendon injury, it is a good practice to perform stretching and warm-up exercises before any participating in any activities. Gradually increase the intensity and length of time of activity. Muscle conditioning may help to strengthen the muscles in the body.