A thorough exam may be difficult if your knee is very swollen, but certain tests can help clarify what's wrong. In the "posterior drawer test," the doctor pushes the shin back while the knee is bent 90 degrees. If the tibia gives more than 5 millimeters, the PCL is likely torn. Your doctor may also perform other tests to help determine whether the ligament is fully torn, partially torn or simply sprained.
In addition, your doctor may use certain imaging tests to examine your injury more closely, including:
- X-rays: These may be ordered to make sure there are no fractured bones in your knee.
- Magnetic resonance imaging (MRI): With an accuracy rate of nearly 90 percent, MRI is an effective tool for determining whether the PCL is torn and, if so, the extent of the damage. It will also provide information on the other knee ligaments and the meniscus (knee cartilage).
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.