The Achilles tendon(tendo calcaneus) is the thickest and strongest tendon in the human body. It connects part of the flexor muscles of the lower leg with part of the skeleton of the foot.
The tendon attaches to the so-called triceps surae muscle, the calf muscle. In extension of this muscle, it runs steeply upwards and becomes significantly thinner. It reaches its narrowest point around four centimetres after the start. It then widens again and finally attaches to the heel bone .
In total, the Achilles tendon is between 15 and 20 centimetres long.
Its most important function is plantar flexion, i.e. the flexion of the foot or toes in the direction of the sole of the foot. It also enables the foot to be lowered in the area of the ankle joint.
The Achilles tendon therefore plays a crucial role in walking and running.
An Achilles tendon rupture (ICD code: S86.0) is also known as an Achilles tendon rupture. It is a complete or partial rupture of the Achilles tendon.
Such a rupture is rarely caused by external force. Rather, the rupture is caused by chronic overloading, for example due to too much or the wrong sports training.
The tendon often ruptures at the narrowest point, but occasionally ruptures also occur at the insertion of the tendon.
The position of the Achilles tendon at the back of the foot and illustration of an Achilles tendon rupture © Henrie / Fotolia
After a rupture of the Achilles tendon, the ankle joint is no longer fully functional, resulting in restricted movement.
Depending on the type of injury, the Achilles tendon rupture can be treated conservatively or surgically.
Rupture of the Achilles tendon is a typical sports injury. The tendon usually ruptures due to sudden and heavy strain. In particular, fast sprints with abrupt stopping movements and many sudden changes of direction put strain on the ankle joint. The following, for example, are risky for the Achilles tendon
- Tennis,
- soccer,
- skiing or
- running.
In untrained people, the Achilles tendon can rupture even with minor strain.
Rapid changes of direction during sport are usually the cause of an Achilles tendon rupture © pavel1964 / Fotolia
In principle, however, a healthy Achilles tendon does not rupture. In most cases, there is already damage to the tendon tissue before the actual rupture.
Inflammation caused by the smallest tears can impair the resistance of the tendon structure. These include achillodynia or Haglund's heel.
Such tendon damage is particularly common in diseases such as
occur. However, prolonged high levels of strain can also cause lasting damage to the tendon tissue.
In addition to intensive sport with sudden movements, there are other risk factors for an Achilles tendon rupture. These include
- congenital or acquired foot deformities (e.g. flat feet),
- unsuitable footwear or
- shortened calf muscles.
A previous partial rupture of the Achilles tendon also increases the likelihood of a second, then usually complete, rupture.
The Achilles tendon can be affected by various diseases © bilderzwerg / Fotolia
An Achilles tendon rupture can develop in the run-up to a
- chronic Achilles tendon irritation (achillodynia) or
- inflammation of the tendon
by pain when tensing or stretching the calf muscles. Prolonged strain on the ankle can also cause pain.
The Achilles tendon rupture itself is noticeable by a loud whip-like sound. This so-called whipping sound is particularly audible in the case of tears caused by very intense strain or sudden movement.
Immediately after the whip crack, the affected person feels sharp, stabbing pain above the heel. The injured person may initially mistake the rupture for a kick to the calf or heel due to the particular pain symptoms.
Dents and/or bruising can be seen and felt in the area above the heel shortly after the rupture. The back of the ankle and the calf area appear swollen.
Due to the injury, the tip of the foot can no longer be lowered towards the sole of the foot. In most cases, running is completely impossible, walking is occasionally possible with severe pain. However, the foot can no longer be rolled under any circumstances.
The doctor usually recognizes an Achilles tendon rupture based on the characteristic symptoms on the foot. In order to confirm his suspected diagnosis, he will ask the affected person to describe the exact course of the accident (anamnesis).
During the physical examination, he pays particular attention to visible or palpable dents in the area of the Achilles tendon as well as bruising.
The Thompson test provides further information. In this test, the patient lies on their stomach and lets the foot with the injury hang freely from the treatment table. The doctor then squeezes the calf muscles with his hands. If the Achilles tendon is intact, the toes move reflexively towards the sole. In this case, the Thompson test is negative.
If the Thompson test is positive, the reflex is absent. This is a clear indication of an Achilles tendon rupture.
Imaging procedures can also be used to make a diagnosis. With an X-ray examination, an orthopaedic surgeon can rule out a bony tear. This injury would not only affect the Achilles tendon, but also parts of the bone.
With the help of an ultrasound examination(sonography), the doctor examines the tear site more closely. This allows him to assess how far apart the tendon ends are. This is particularly important for the choice of treatment method.
If the ultrasound examination does not provide clear results, a magnetic resonance imaging(MRI) scan can also provide further details.
The aim of treatment is to restore the full functionality and load-bearing capacity of the tendon and the ankle joint. Both conservative and surgical measures can be used for this purpose.
Conservative treatment of an Achilles tendon rupture
Surgery is not always necessary to treat an Achilles tendon rupture. In some cases, conservative treatment may be sufficient:
- in the case of a partial rupture,
- in patients who are not very active in sports,
- if there is a higher risk of complications for surgery, for example due to previous illnesses.
For conservative treatment, patients are given a lower leg cast. This fixes the foot in a pointed foot position for two weeks. This cast is then replaced by shoe or boot orthoses that are raised in the heel area. This pointed foot position allows the tendon ends to grow together more easily.
In the course of conservative treatment, the orthopaedic surgeon adapts these orthoses more and more to the physiological foot position.
To check the success of the therapy, the doctor also carries out ultrasound examinations at regular intervals.
After therapy, the patient must keep the affected foot immobilized for some time © sunnychicka / Fotolia
However, conservative therapy is only possible if the tendon ends can still come into contact with each other. If the tendon ends are very far apart, they can no longer grow together and must be joined in an operation.
Surgical treatment of an Achilles tendon rupture
Surgery is mainly performed on young athletes or in the case of severe tears. The advantage of surgery is that the Achilles tendon is less likely to rupture a second time compared to conservative treatment. However, complications can also occur during surgery, as with any other operation.
During the operation, the surgeon stitches the ends of the tendon back together. To do this, he makes an incision directly above the Achilles tendon and opens the tendon tube that surrounds the tendon. In most cases, a special suture material is used to suture the tendons, which breaks down by itself after a few weeks.
To promote the healing process, patients are given a plaster cast for a few days after the operation.
With both conservative and surgical treatment, it is important to put weight on the foot again as soon as possible. Limited exercise therapy can be useful here. However, sporting activities are only possible again after a few months.
The course of the disease, the healing time and the prognosis depend primarily on the treatment. Appropriate, early therapy with supervised follow-up treatment by a physiotherapist is of the utmost importance. The function of the ankle joint and the load-bearing capacity of the tendon can then be restored in many cases.
After around 6 months, most patients can play sport again without pain or even take part in competitions.
Competitive athletes, on the other hand, are rarely able to build on their previous successes after tearing their Achilles tendon. In many cases, they have to end their career.
