The most frequent injury mechanism in isolated PCL tears is a direct blow on the anterior tibia with the knee flexed thus driving the tibia posteriorly. Automobile accidents in which the knee hits the dashboard and soccer injuries in which an athlete receives a blow to the anterior surface of the tibia during knee flexion characteristically produce this type of injury.
The most characteristic diagnostic finding in a knee with a PCL rupture is the 'posterior sag sign' meaning the apparent disappearance of the tibial tubercle in lateral inspection when the knee is flexed 90 degrees.
This is due to gravity-assisted posterior displacement of the tibia in relation to the femur. A positive posterior drawer test performed at 90 degrees of flexion and a knee hyperextension sign are sensitive but nonspecific tests. False negative findings are frequent, especially in acute cases.
If necessary, the clinical diagnosis of the PCL tear can be verified by magnetic resonance imaging, examination under anaesthesia, arthroscopy, or a combination of these modalities. If a PCL avulsion fragment has been dislocated, surgical treatment is recommended.
In isolated, complete midsubstance tears of the PCL the majority of the recent studies recommend conservative treatment, since abnormal residual posterior laxity1 in most of these knees is consistent with functional stability and minimal symptoms. Although a posterior cruciate ligament injury generally causes less pain, disability and knee instability than does an ACL tear, it can still sideline you for several weeks or months.
If there are no associated injuries to other parts of your knee, the signs and symptoms of a posterior cruciate ligament injury can be so mild that you might not notice that anything's wrong. Over time, the pain might worsen and your knee might feel more unstable. If other parts of your knee have also been injured, your signs and symptoms will likely be more severe. The posterior cruciate ligament can tear if your shinbone is hit hard just below the knee or if you fall on a bent knee.
These injuries are most common during:. Being in a motor vehicle accident and participating in sports such as football and soccer are the most common risk factors for a PCL injury. In many cases, other structures within the knee — including other ligaments or cartilage — also are damaged when you injure your posterior cruciate ligament. Depending on how many of these structures are damaged, you might have some long-term knee pain and instability.
You might also be at higher risk of eventually developing arthritis in your affected knee. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
This content does not have an English version. This content does not have an Arabic version. Overview Posterior cruciate ligament Open pop-up dialog box Close. Posterior cruciate ligament Two of the four ligaments that connect the thighbone femur to the shinbone tibia are the posterior cruciate ligament and the anterior cruciate ligament ACL. Request an Appointment at Mayo Clinic. Share on: Facebook Twitter.
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