Assessing a possible meniscal tear is usually done by locating pain and crepitation along the joint line. This palpation for these symptoms must be done while simultaneously applying a valgus or varus stress to the knee.
The current standard that we use for assessment of meniscal tears is to feel along the joint line to see if there is any associated crepitation with a forced varus or valgus stress at 3O° of knee flexion. In addition, we increase the amounts of knee flexion while at the same time palpating from the anterior to the posterior aspect of the joint line. If there is any associated joint line pain and/or crepitation, is primarily due to a meniscus tear or an articular cartilage flap, we are able to identify that there is some joint pathology with these testing maneuvers.
Other means used to test for meniscal tears include pain with maximal knee flexion, which should be in the posterior rather than the anterior aspect of the knee. Posterior joint pain may also be felt while doing a deep squat, or pain with twisting or turning. We generally get standing AP view and lateral radiographs on all patients that have evidence of joint line pain and crepitation to make sure that there is no underlying arthritis present. In those patients who have some doubts about their diagnosis or in whom we feel joint line pain but not associated crepitation, a MRI to rule out a meniscal tear may be indicated. The MRI scans are highly accurate for medial meniscal tears and just slightly less accurate for diagnosis of lateral meniscal tears (LaPrade, et al, 1994).
Pain in the posterior aspect of the knee with maximal flexion is usually indicative of a posterior horn meniscal tear.
Deep posterior knee pain with squatting can also be indicative of a meniscal tear.
