Examination of the knee video
Look initially from the end of the bed for loss of symmetry and loss of normal leg alignment such as varus deformity – where distal to the knee is deviated medially leading to a bow-legged appearance – or valgus deformity – where distal to the knee is deviated laterally leading to a knock-kneed appearance.
Look for rashes, scars, swellings, and muscle wasting and any fixed flexion of the knee.
Temperature is assessed by starting at the mid-thigh and moving down, and comparing both knees to each other. Feel around the border of the patella for tenderness and behind the knee for popliteal cysts or swellings.
Assess for a knee effusion by using a patellar tap; while pushing vertically down on the suprapatellar pouch two or three fingers of the other hand attempt to bounce the patella. For smaller effusions, cross-fluctuation or the bulge sign is performed by emptying the medial gutter of any fluid. When the hand is swept over the suprapatellar pouch and down the lateral gutter the medial side may refill – producing a bulge of fluid.
With the knee flexed to 90° the joint line is opened and can be palpated along with the patellar tendon insertion.
Movements of full flexion and extension are performed both actively and passively. Excessive extension is a sign of hypermobility. Both sides should be compared.
Anterior Draw Test: With the knee flexed to 90° the knee should be viewed from the side. A posterior sag or step-back in the tibia may be suggestive of posterior cruciate ligament damage. With the hand behind the knee and checking the hamstrings are relaxed the thumbs are placed over the tibia and a forward pull applied. Significant movement indicates a positive draw test and suggests anterior cruciate ligament damage. The lower leg may be stabilised during this by the examiner’s forearm.
Collateral Ligament Assessment: Medial and lateral collateral ligaments are assessed by flexing the knee to 15° and alternately stressing each side of the knee.
With the patient standing, popliteal swellings may more readily be seen and varus or valgus deformities may be more apparent with the patient weight-bearing.
Functional assessment includes asking the patient to walk.