Pivot shift test
The pivot shift test is performed on a supine patient.
At the start the subject's knee is permitted to droop into complete extension and simultaneously the clinician exerts both internal rotation and valgus forces, such that the tibia subluxes forwards.
Then the clinician flexes the knee, but continues to exert the internal rotatory and valgus forces.
If the tibia abruptly shifts forwards with relation to the femur into the normal anatomical position then the pivot shift test is positive. This shift usually happens at ~20-30° of tibial flexion.
A positive test has been demonstrated to be highly specific for abnormal laxity of the anterior cruciate ligament (ACL). Its specificity remains high for injury in the patient who has had reconstruction of their ACL.