The McMurray test is performed by bringing the knee into full flexion and then laterally rotating the tibia. This maneuver primarily tests the posterior horn of the menisci, as the anterior horn is not as easily assessed due to lower pressure.
Here's a breakdown:
- Patient Positioning: The patient lies supine (on their back).
- Knee Flexion: Flex the patient's knee as far as it can comfortably go (full flexion).
- Tibia Rotation: While maintaining flexion, laterally (externally) rotate the tibia. This movement stresses the medial meniscus. To test the lateral meniscus, medially (internally) rotate the tibia.
- Extension and Palpation: Slowly extend the knee while continuing to rotate the tibia. Palpate the joint line (the space between the femur and tibia) during the extension.
- Positive Test: A positive McMurray test is indicated by:
- A palpable or audible "click" or "thud" along the joint line.
- Pain elicited during the maneuver.
It's crucial to note that a positive McMurray test suggests a meniscal tear, but further imaging (like MRI) is often required for confirmation and to determine the severity and location of the tear. The anterior portion of the meniscus may not always be accurately assessed with this method.
