Anterior cruciate ligament tear

The ACL (Anterior Cruciate Ligament) tear is the result of direct or indirect trauma, is practically unilateral and can be complete or incomplete .

Such an injury does not necessarily have to be isolated, but may be accompanied by a meniscal tear or other ligament (PCL or collateral ligament ) lesions; The medial meniscus and medial ligament are affected more frequently than the external structures.
There are a number of factors that contribute to a ruptured ligament , including certain sports, a surface that is too hard, equipment used, hormone levels, anatomical characteristics, etc.

Statistically, the risk of an anterior cruciate ligament injury is much higher in athletes than in non-athletes, but there are big differences between the individual sports.
The sports with a high rate of ACL injuries are : soccer, indoor soccer, football, basketball , skiing, gymnastics and volleyball.
It mainly affects men.

There are three injury mechanisms that lead to a ligament rupture:

  • Strong overstretching (hyperextension); often leads to an isolated but complete tear of the ACL, typical example: kicking into the void (soccer).
  • outward rotation with valgus flexion stress; this trauma is the most common cause of anterior cruciate ligament injury. The medial ligament is primarily affected, but the ACL also tears in more severe trauma ; Skiers are particularly at risk here.
  • Internal rotation with varus flexion stress, most common sprain trauma in soccer players.

The tear of the anterior cruciate ligament can be incomplete (partial), this is referred to as a torn ligament or a partial rupture.

Rarely does this type of injury occur in children under the age of 13.


What are the symptoms and signs of an anterior cruciate ligament tear?

The main symptoms are pain and limitation of movement; The signs of a tear are: swelling (oedema), bloody joint effusion (hemarthrosis), redness and overheating of the knee joint , typical of inflammation .

Injuries to the anterior cruciate ligament often occur in combination with a tear in the medial meniscus and medial ligament, which is why other symptoms can become noticeable, such as joint blockage or instability in the inner knee area.
There is often a cracking, snapping sound when the ligament is torn, accompanied by severe pain and instability; the affected person is unable to finish practice or play.

2-3 days after the injury, the pain and swelling subside and some of the symptoms subside.

If the anterior cruciate ligament is torn, the knee joint remains unstable, but if the leg has strong thigh muscles, this has a stabilizing effect on the joint.

The pain occurs in the back of the knee and depends on the volume of the knee joint effusion.

How is the diagnosis made?

The diagnosis must always be made by a specialist ; who can have imaging procedures carried out to confirm the diagnosis. To assess
the significance of the swelling , the ballottement test of the patella is performed: the doctor moves the kneecap sideways or up/down; if it “rebounds” the test is positive. When the anterior cruciate ligament is completely torn, the pain is very severe.

The clinical examination begins with a precise vision of the medical history: the patient describes in detail how the injury occurred and informs the doctor about any previous illnesses, risk factors, etc. A joint puncture (arthrocentesis)
can then be performed, ie the fluid that is causing the swelling in the knee is sucked out with a syringe and examined to see whether it only contains inflammatory fluid or also blood. The specialist will also perform various tests : Lachman test, anterior drawer test and pivot shift test.

Magnetic resonance tomography  (MRI of the knee joint) is recommended as an imaging method , which provides a sufficiently reliable representation of the ligaments, is a non-invasive method and does not have any negative side effects like a CT scan.
Ultrasound and X-ray are not able to show the inside of the knee.
The MRI findings show a torn cruciate ligament with an uneven appearance, as well as fissures in the meniscus.

What are the treatment options for a ruptured ACL?

There are basically two treatment options: conservative or surgical .
The choice depends on the patient: as a rule, young and athletic patients are operated on

ert; Older or less active people with an isolated cruciate ligament tear usually do not undergo surgery because rehabilitation is long, it takes time for the new cruciate ligament to stabilize, and the tendons from which tissue was harvested for repair become shorter and weaker.
the night

part of conservative treatment is that the knee does not perform physiological movement unless the ligament is repaired; This means that the joint wears out prematurely (arthrosis) and the risk of sprains increases due to the reduced stability .

Treatment for anterior cruciate ligament rupture

  • Without surgery , physical therapy consists of a progressively increased exercise program to reduce discomfort and swelling and improve mobility .
    If the injury is associated with a fracture of the meniscus and/or cartilage , the course of therapy is different. The protocol is to apply body weight to the injured limb using a knee brace or splint, with the help of crutches if necessary. Initially, isometric contractions of the thigh quadriceps and hamstrings are performed; also mustbegin passive mobilization as soon as possible , taking the pain threshold into account. If the swelling subsides, the focus is on consistently building up the muscles  in the hamstrings and calf muscles because they stabilize the knee; at the beginning concentric exercises are performed, later on eccentric exercises are performed.
    As pain decreases, a proprioceptive exercise program is important; it involves maintaining certain positions with unstable balance, which improves postural control.
    Only a third of patients can fully restore their original condition, the others will experience early joint degeneration and/or dislocation within a year of trauma .
  • Surgery  is performed arthroscopically by autografting, that is, inserting part of another endogenous tendon (eg, the quadriceps-patellar tendon, semitendinosus, gracilis, or fascia lata); a donor cruciate ligament can also be used.
    Ideally, a physiotherapy cycle should be carried out before the operation in order to relieve the severe pain and, above all, to reduce the swelling in the joint, because a severely inflamed joint cannot be operated on.
    The primary goals of preoperative exercise therapy are: regaining full range of motion, strengthening the thigh muscles, and general physical fitness.
    If a cruciate ligament tear is not operated on, the knee joint can develop arthrosis at an early stage and it can lose the necessary stability.

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