ANTERIOR CRUCIATE LIGAMENT (ACL) INJURY/TEAR
Whether you're a professional sports player or a just an amateur, you're never safe from knee injuries. Speaking of knee injuries, let's highlight the one that occurs most often: the anterior cruciate ligament (ACL) injury/tear.
What is an ACL injury?
Athletes who regularly practise sports such as football, rugby or basketball tend to show a higher risk at tearing their ACL because of the movements they inflict on their knees but it should still be known that sports amateurs and even people who do not practise sport are also often exposed to this type of injury.
The ligaments present in our knees are strong bands of tissue that connect one bone to another. The ACL in particular is one of the two ligaments that crosses in the middle of the knee and connects the femur (thighbone) to the tibia (shinbone). This cruciate ligament is more or less responsible for the stability of the knee and should therefore be closely analysed when a tear is suspected.
Causes of an anterior cruciate ligament (ACL) injury
The anterior cruciate ligament can be injured in several ways:
- Sudden change of direction.
- Suddenly stopping.
- Landing from a jump incorrectly.
- Direct contact or collision, such as a football tackle.
- Slowing down while running.
- Pivoting with your foot firmly planted.
Symptoms of an anterior cruciate ligament injury
The symptoms of an ACL injury usually include:
- A loud "pop" or a "popping" sensation in the knee.
- Swelling that begins within a few hours.
- A feeling of instability or "giving way" with weight bearing.
- Severe pain and inability to continue activity.
- Loss of range of motion.
How can we examine the ACL?
There are several techniques available for assessing the ACL:
GNRB arthrometer
Arthrometry/Laximetry
Running a diagnosis on the anterior cruciate ligament state using an arthrometer is nowadays becoming more and more present around the world. Arthrometers indeed reproduce the physical examination tests but with objective results and in a controlled manner. The first arthrometer created was the KT-1000 and its technology is based on the anterior drawer test. To diagnose a torn ACL, this device would emit a sound when the displacement between the tibia and the femur would be superior to 3mm at 134N meaning the anterior cruciate ligament is torn.
This device was used a lot on a worldwide scale but it quickly showed its limitations especially in terms of test reproducibility and precision. This is one of the reasons why Genourob created its own arthrometer the GNRB, which is the first automated anterior drawer test arthrometer /Laximeter that performs dynamic analysis. A GNRB test indeed allows diagnosis of the ACL's state by applying several forces on the tibia and analyzing its displacement. Besides, this arthrometer can be used in the pre-surgery and post-surgery phase of patient management.
Physical examination
This technique is perhaps the simplest one applied by the orthopaedic community. During this examination, the doctor will check all the structures of the injured knee by performing tests such as the Lachman test, the drawer test, etc. He will then perform the same tests on the healthy knee and compare the results in order to have a proper diagnosis of the state of the ACL.
Physical examination is perhaps the technique which is most used all around the world but it is not close at being the most efficient one as the results are not objective and it depends on user experience, patient muscle activity and sensibility.
Magnetic resonance imaging (MRI) scan
This device creates images of soft tissues like the anterior cruciate ligament (ACL). However, blood surrounding the anterior cruciate ligament can make it difficult to assess a torn ACL. Besides, tests that are done with this device are also static as the patient lies still while the examination.