As already explained above, the rupture of the Achilles tendon is accompanied by an audible bang (whiplash). In addition, the patient suffers from stabbing pain and is no longer capable of active plantar flexion due to calf compression. It is typical that the patient is no longer able to stand on one leg or toe on the diseased leg.
A tear of the Achilles tendon becomes visible from the outside due to a swelling at the back of the ankle joint, possibly also a bruise becomes visible. The doctor can also feel a distinct dent in the musculature. A rupture of the Achilles tendon is usually noticed by the affected person due to the immediate onset of pain, which usually makes further strain on the affected extremity immediately impossible.
The intensity of the pain depends on the extent of the damage caused to the tendon by a complete or incomplete rupture and can be very intense even under resting conditions. The injured person feels as if he or she has received a violent kick against the heel. The pain, the quality of which is described as suddenly shooting and stabbing, is intensified by stepping on the ball of the toe and trying to stand on the ball of the toe. The ability to walk is severely restricted. In addition to the correct execution of the treatment measures by the attending physician, the patient should also strictly observe the prohibition of sports and the medical instructions, as pain can become chronic even after successful treatment and lead to permanent limitations of the patient’s ability to walk (achillodynia).
A rupture of the Achilles tendon can be diagnosed in different ways. If the tendon is completely severed, a gap above the heel can often be palpated. In addition, a fresh rupture of the Achilles tendon reveals a severe and painful swelling of the tissue, as well as redness or blue discoloration of the heel region.
In addition, the patient can no longer walk on tiptoe because the rupture of the Achilles tendon cuts the connection between the calf muscles and the heel bone. If the patient lies on his stomach on a couch and his calf muscles are squeezed together, the foot would normally have to bend towards the sole of the foot (plantar flexion). With a torn Achilles tendon, this no longer happens for the reasons mentioned above.
This phenomenon is also called positive Thompson test. The instrumental diagnosis of an Achilles tendon rupture is based primarily on sonography (ultrasound examination). The treating physician can directly display the affected region on the screen with the ultrasound device and assess the extent of the rupture.
The choice of the treatment method is then also determined by this. If the ends of the Achilles tendon are only slightly apart, the patient can usually be helped by conservative therapy. However, if the distance between the ends is large, often only surgery can help.
In addition to ultrasound, an MRI of the Achilles tendon can also help to diagnose a torn Achilles tendon. The MRI is used if the ultrasound is not conclusive enough or if atypical complaints are indicated without a clear cause. The MRI makes it easier to identify already healed ruptures, incomplete tears and other changes in the tendon.
As soon as the first symptoms of the Achilles tendon rupture have subsided, the patient will notice that he or she is no longer able to walk normally. This is known as functional failure, which is also noticeable in that the patient is usually not able to perform a (monopod) toe stand. In the first hours after the Achilles tendon rupture, the treating physician can feel a dent a few centimeters above the actual Achilles tendon insertion.
However, this is only possible in the first few hours after the accident. Later, a haematoma forms there due to bleeding, which would make the diagnosis of the Achilles tendon tear much more difficult. The plantar flexion is usually reversed after the Achilles tendon rupture.
In patients with deep flexor muscles, residual flexion may be retained, although this is usually significantly different from the normal condition. In order to better assess plantar flexion (bending of the foot), the so-called Thompson test can be performed to diagnose the Achilles tendon rupture. For this, the treating physician presses on the calf area.
This compression makes plantar flexion impossible in the case of an Achilles tendon rupture. Typical for an Achilles tendon rupture is also the failure of the Achilles tendon reflex, the testing of which is usually quite painful for the patient. In about 70% of all cases, a rupture of the Achilles tendon can also be detected and precisely localized by means of sonography. In order to exclude a bony tear of the Achilles tendon, an X-ray can also be taken. This exclusion can have decisive effects on the therapeutic treatment (see Therapy of Achilles tendon rupture).