Tests Used to Evaluate Knee Injuries

Anterior Drawer Test The anterior drawer test evaluates the anterior cruciate ligament. To perform this test, place the knee in ninety degrees of flexion with the patient laying supine and the foot stabilized on the table. Grasp the posterior aspect of the tibia over the upper calf muscle and pull forward with a steady force. If the tibia bone pulls forward more than normal (compare with the uninjured leg) the test is positive. This is indicative of an anterior cruciate ligament tear.

Posterior Drawer Test The posterior drawer test evaluates the posterior cruciate ligament. To perform this test, place the knee in ninety degrees of flexion with the patient laying supine and the foot stabilized on the table. Grasp the anterior aspect of the tibia over the tibial tuberosity and push forward (displacing the tibia posteriorly) with a steady force. If the tibia moves posteriorly more than normal (compare with the uninjured leg) the test is positive. This is indicative of a posterior cruciate ligament tear.

Valgus Stress Test The valgus or abduction stress test evaluates the medial collateral ligament. To perform this test, place the knee in thirty degrees of flexion. While stabilizing the knee, abduct the ankle. If the knee joint abducts greater than normal (compare with the uninjured leg), the test is positive. This is indicative of a medical collateral ligament tear.

Varus Stress Test The varus or adduction stress test evaluates the lateral collateral ligament. To perform this test, place the knee in thirty degrees of flexion. While stabilizing the knee, adduct the ankle. If the knee joint adducts greater than normal (compare with the uninjured leg), the test is positive. This is indicative of a lateral collateral ligament tear.

Lachman’s Test With the patient lying flat and relaxed, the examiner bends the knee slightly (about 20 degrees). The examiner then stabilizes the thigh while pulling the shin forward. The test places stress on the ACL. Both the amount of movement (shifting) of the shin bone, as well as the feel of the endpoint of movement (how solid the ligament feels), offer information about the ACL. Knees with a damaged ACL may demonstrate more movement and a less firm endpoint during a Lachman test.

Recurvatum Test Steps Patient lies supine with the lower limbs relaxed Examiner grasps the 1 st MT of each foot & lifts both feet off of the examining table Examiner instructs the patient to keep his/her quadriceps relaxed & observes the tibial tuberosities Positive Test Affected knee goes into relative hyperextension on the lateral side with the tibia & tibial tuberosity rotating laterally Positive Test Implications Sprain of the lateral joint capsule, PCL, and can involve the LCL (plus other possible lateral structures)

Posterior Tibial Sag Test The patient is supine with her hips and knees bent to ninety-degrees.  The examiner supports the patient's legs at the ankles and observes for an indication that the tibia has shifted posteriorly (toward the table) as compared to the uninvolved knee.

McMurry’s Test Steps Patient is supine Examiner stands lateral & distal to the involved knee with one hand supporting the lower leg Examiner positions thumb & index finger of the opposite hand in the anteromedial & anterolateral joint lines on either side of the patellar tendon Examiner keeps the tibia in the neutral position, applies a valgus stress through knee flexion & varus stress through knee extension Examiner internally rotates the tibia & applies a valgus stress through knee flexion & a varus stress through knee extension Examiner externally rotates the tibia & applies a valgus stress through knee flexion & a varus stress through knee extension Positive Test Popping, clicking, or locking of the knee; pain from within the joint Positive Test Implications Possible meniscus tear