A radiographic examination is required for patients with acute injuries with one or more of the following: patient over the age of 55, tenderness at the head of the fibula, isolated tenderness of the patella, inability to flex to 90 degrees and inability to bear weight both immediately and in the emergency department.
Examination of the knee is most productive when the patient doesn’t have pain, spasm, swelling and that is best performed 30 minutes after acute injury.
Collateral ligaments are checked for laxity to varus and valgus stress, with the knee at 30 degrees of flexion and then at full extension.
The valgus stress test measures the medial collateral ligament laxity with the patient lying supine, the lower thigh resting on the table’s edge and the leg hanging off the table: in this position the hip is extended, hamstrings are relaxed, and the thigh is stabilized.