An additional test of posterior cruciate ligament injury is the posterior sag test, where, in contrast to the drawer test, no active force is applied. Rather, the person lies supine with the leg held by another person so that the hip is flexed to 90 degrees and the knee 90 degrees.Posterior Sag Test From The University of West Alabama, Athletic Training & Sports Medicine Center. Retrieved Feb 2011 The main parameter in this test is step-off, which is the shortest distance from the femur to a hypothetical line that tangents the surface of the tibia from the tibial tuberosity and upwards. Normally, the step-off is approximately 1 cm, but is decreased (Grade I) or even absent (Grade II) or inverse (Grade III) in injuries to the posterior cruciate ligament. The posterior drawer test is one of the tests used by doctors and physiotherapists to detect injury to the PCL. Patients who are suspected to have a posterior cruciate ligament injury should always be evaluated for other knee injuries that often occur in combination with an PCL injuries. These include cartilage/meniscus injuries, bone bruises, ACL tears, fractures, posterolateral injuries and collateral ligament injuries.
