Supplementary notes for the Knee Examination:
Draping: ideally the joint above and below the joint to be inspected should be uncovered and inspected. However, the hip is a deep joint and is therefore difficult to observe, so observation of the patient standing and walking is more appropriate.
Erythema- redness or swelling of the skin or mucous membrane from engorgement of the capillaries near the skin’s surface.
Genu valgum- (valgus deformity of the knee) a skeletal conformation where the tibia curves away from the midline, proximal to distal (commonly known as “knock kneed”).
Genu varus- (varus deformity) the skeletal conformation in which the tibia curves toward from the midline, proximal to distal (commonly known as “bow-legged”).
Genu recurvatum- a knee joint
conformation commonly known as “back knees” in which the joint can hyperextend
such that the thigh and leg form a curve.
Joint line tenderness: to detect any abnormalities or injuries to the joint, components of the joint should be palpated one at a time, see figures 1 and 2.
Detection of a joint effusion: effusion-The escape of fluid into a part or tissue, as an exudation or a transudation. Because of the anatomy of the knee joint capsule, fluid can shift between various regions of the joint, and this can used in the detection of the effusion (figure 2).
Testing the collateral ligaments: To examine a collateral ligament of the knee, the examiner should place the joint in slight flexion, place one hand over the ligament to be tested (i.e. when testing the medial collateral, place one hand over the medial aspect of the knee), and then place strain on the ligament to be tested (i.e. to test the medial collateral, place a valgus strain on the tibia). See figures 3.
Testing the cruciate ligaments: The cruciate ligaments prevent unwanted movement of the tibia relative to the femur in the sagital plane. The anterior cruciate ligament originates on the anterior aspect of the tibia and the posterior originates posteriorly (see figure 4).
Testing for meniscal damage: To test for tears in the menisci, the examiner attempts to capture the tear between the articular surfaces of femur and tibia during movement from flexion to extension. In order to specifically test each meniscus, the joint must be manipulated as shown in figures 5.
