The Achilles tendon is a conjoined tendon composed of the gastrocnemius and soleus muscles with occasional contribution from the plantaris muscle, and it inserts on the calcaneal tuberosity. The plantaris muscle is absent in 6% to 8% of individuals. The Achilles tendon is approximately 15-cm long and is the largest and strongest tendon in the human body. The tendon spirals approximately 90 from its origin to its insertion and this twisting produces an area of stress approximately 2- to 5-cm proximal to its insertion. The tendon has no true synovial sheath; instead it is wrapped in a paratenon. The Achilles tendon experiences the highest loads of any tendon in the body, and bears tensile loads up to 10 times body weight during athletic activities. The tendon most commonly ruptures in a region 2- to 6-cm proximal to its insertion.
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.
It is important to know that pain at the back of the heel is not always due to Achilles tendon rupture. It may be due to bursitis (fluid accumulation in the heel due to repeated irritation) and tendonitis (pain along the Achilles tendon due to constant friction and irritation). The above disorders tend to improve with use of pain medications and rest, whereas Achilles tendon rupture requires surgery and/or a cast.
Laboratory studies usually are not necessary in evaluating and diagnosing an Achilles tendon rupture or injury, although evaluation may help to rule out some of the other possibilities in the differential diagnosis. Plain radiography. Radiographs are more useful for ruling out other injuries than for ruling in Achilles tendon ruptures. Ultrasonography of the leg and thigh can help to evaluate the possibility of deep venous thrombosis and also can be used to rule out a Baker cyst, in experienced hands, ultrasonography can identify a ruptured Achilles tendon or the signs of tendinosis. Magnetic resonance imaging (MRI). MRI can facilitate definitive diagnosis of a disrupted tendon and can be used to distinguish between paratenonitis, tendinosis, and bursitis.
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.
Some surgeons feel an early surgical repair of the tendon is beneficial. The surgical option was long thought to offer a significantly smaller risk of re-rupture compared to traditional non-operative management (5% vs 15%). Of course, surgery imposes higher relative risks of perioperative mortality and morbidity e.g. infection including MRSA, bleeding, deep vein thrombosis, lingering anesthesia effects, etc.
Good flexibility of the calf muscles plays an essential role in the prevention of Achilles tendon injuries. It is also important to include balance and stability work as part of the training programme. This should include work for the deep-seated abdominal muscles and for the muscles that control the hip. This might at first appear odd, given the fact that the Achilles are a good distance from these areas, but developing strength and control in this area (core stability) can boost control at the knee and ankle joints. Training errors should be avoided. The volume, intensity and frequency of training should be monitored carefully, and gradually progressed, particularly when introducing new modes of training to the programme. Abrupt changes in training load are the primary cause of Achilles tendinopathy.