This is one of those injuries that can come out of nowhere. You know it when you have it. The prognosis for recover is pretty good but in older patients with other health problems like Diabetes run the risk of having healing issues. That is not usually the case in the young athlete.

Photo Credit: eOrthopod.com

Anatomy

The Achilles tendon is the largest tendon in the human body and can withstand forces of 1,000 pounds or more. But it is also the most vulnerable and frequently ruptured tendon, and both professional and weekend athletes can suffer from Achilles tendonitis, a common overuse injury and inflammation of the tendon. It is a strong, fibrous band that connects the calf muscle to the heel. The calf is actually formed by two muscles, the underlying soleus and the thick outer gastrocnemius. Together, they form the gastroc-soleus muscle group. When they contract, they pull on the Achilles tendon, causing your foot to point down and helping you rise on your toes. This powerful muscle group helps when you sprint, jump, or climb. Several different problems can occur that affect the Achilles tendon, some rather minor and some quite severe.

The Injuries

Achilles Tendonitis

A violent strain can cause injury to the calf muscles or the Achilles tendon. This can happen during a strong contraction of the muscle, as when running or sprinting. Landing on the ground after a jump can force the foot upward, also causing injury. The strain can affect different portions of the muscles or tendon. For instance, the strain may occur in the center of the muscle. Or it may happen where the muscles join the Achilles tendon (called the musculotendinous junction). Chronic overuse may contribute to changes in the Achilles tendon as well, leading to degeneration and thickening of the tendon.

Achilles tendonitis usually occurs further up the leg, just above the heel bone itself. The Achilles tendon in this area may be noticeably thickened and tender to the touch. Pain is present with walking, especially when pushing off on the toes.

Achilles Tendon Rupture

This is commonly an acceleration injury e.g. pushing off or jumping up. The classic example is a middle-aged tennis player or weekend warrior who places too much stress on the tendon and experiences a tearing of the tendon. In some instances, the rupture may be preceded by a period of tendonitis, which renders the tendon weaker than normal.

An Achilles tendon rupture is usually an unmistakable event. Some bystanders may report actually hearing the snap, and the victim of a rupture usually describes a sensation similar to being violently kicked in the calf. Following rupture the calf may swell, and the injured person usually can't rise on his toes.

Photo Credit: eOrthopod.com

The Mechanism of Injury

The exact cause of ruptures is hard to say. It can happen suddenly, without warning, or following a tendonitis. It seems that weak calf muscles may contribute to problems. If the muscles are weak and become fatigued, they may tighten and shorten. Overuse can also be a problem by leading to muscle fatigue.

The more fatigued the calf muscles are, the shorter and tighter they will become. This tightness can increase the stress on the Achilles tendon and result in a rupture.

A rupture is likely when the force on the tendon is greater than the strength of the tendon. If the foot is dorsiflexed while the lower leg moves forward and the calf muscles contract, a rupture may occur. Most ruptures happen during a forceful stretch of the tendon while the calf muscles contract.

A classic sign of an Achilles tendon rupture is the feeling of being hit in the Achilles are. There is often a "pop" sound. There may be little pain, but the person can not lift up onto his toes while weight bearing. (See Symptoms Below)

• For Runners: Rapidly increasing your running mileage or speed
• Adding hill running or stair climbing to your training routine
• Starting up too quickly after a layoff
• Trauma caused by sudden and/or hard contraction of the calf muscles when putting out extra effort such as in a final sprint
• Overuse resulting from the natural lack of flexibility in the calf muscles

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."
• 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

Diagnosis is almost always by clinical history and physical examination. The physical examination is used to determine where your leg hurts. The doctor will probably move your ankle in different positions and ask you to hold your foot against the doctor's pressure. By stretching the calf muscles and feeling where these muscles attach on the Achilles tendon, the doctor can begin to locate the problem area.

The doctor may run some simple tests if a rupture is suspected. One test involves simply feeling for a gap in the tendon where the rupture has occurred. However, swelling in the area can make it hard to feel a gap.

Another test is done with your leg positioned off the edge of the treatment table. The doctor squeezes your calf muscle to see if your foot bends downward. If your foot doesn't bend downward, it's highly likely that you have a ruptured Achilles tendon.

When the doctor is unsure whether the Achilles tendon has been ruptured, a magnetic resonance imaging (MRI) scan may be necessary to confirm the diagnosis. This is seldom the case. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. The MRI creates images that look like slices and shows the tendons and ligaments very clearly. This test does not require any needles or special dye and is painless.

An ultrasound test may be ordered. An ultrasound uses high-frequency sound waves to create an image of the body's organs and structures. The image can show if an Achilles tendon has partially or completely torn. This test can also be repeated over time to see if a tear has gotten worse.

By using the MRI and ultrasound tests, doctors can determine if surgery is needed. For example, a small tear may mean that a patient might only need physical therapy and not surgery.

Treatment

Surgical repair of the Achilles tendon, with or without augmentation, is generally considered the most appropriate form of management for active individuals seeking the best functional result. This is performed in order to regain the maximum strength of the Achilles, as well as the normal pushing off strength of the foot. The strength of the muscle depends on the correct tension between the muscle and the tendon.

When the tendon ruptures, the ends of the tendon separate and multiple little strands of the tendon are present like pieces of spaghetti. Usually the incision is made just to the side of midline so shoes will not rub on the site of the scar. The torn ends of the Achilles tendon are identified and strong sutures are placed in both ends of the tendon. These strong sutures are then tied together to repair the tendon. This is known as an "open" technique.

There are complications associated with this type of surgery such as wound healing and a high incidence of infection in the skin after this type of surgery. This is an important consideration, since infection in the skin can lead to devastating problems with the skin and tendon. This problem of skin infection has, in the past, led surgeons away from surgical methods of treatment.

Newer techniques, called percutaneous, requires only a tiny incision(s) of one to two centimeters in length. This is far more accurate surgery and recovery after this procedure is easier and the surgical complication rate is extremely low. It should be noted that this type surgery should only be done within one week following injury.

The Technique

Figure 1: Three 3cm transverse incisions are made over the Achilles tendon. The first is directly over the palpable defect, the other about 4cm proximal and 4cm distal to the first incision.

Figure 2: The proximal incision is made to the medial side of the tendon to reduce the risk of damage to the sural nerve.

Figure 3: Insertion of the 1 PDS II double strand suture on a long curved needle transversely through the distal incision passing through the substance of the tendon and through the same incision.

Figure 4: The needle is then reintroduced medially into the distal incision through a different entry point in the tendon and passed longitudinally through the tendon, to lock the tendon, and is directed towards the middle incision and out through the ruptured tendon end. The suture still protruding from the distal incision is re-threaded onto the needle and re-introduced laterally into the distal incision and into the tendon, passing it proximally through the tendon to exit from the middle incision. Traction is applied to the suture to ensure a satisfactory grip within the tendon. The same procedure is performed in the proximal end of the tendon.

Figure 5: The sutures are tied with the ankle in the neutral plantar flexion; the tension is then assessed by observing the contralateral limb as the sutures are tied.

From Dr.'s D. MCCLELLAND and N. MAFFULLI, North Staffordshire Royal Infirmary.

Traditionally, this has been followed by rigid immobilization in a plaster cast for four to nine weeks.

Information taken from Eothorpod and About.com