*3.3.3 The lateral radiograph*

A true lateral radiograph of the knee should be obtained, showing overlap of the distal and posterior cortices of the medial and lateral femoral condyles. The lateral view allows determination of the patellar height and depth of the femoral trochlea. Several measurements have been described to measure patella alta. Controversy exists as to which radiographic measurement is most accurate. When the patella does not engage in the trochlea by 15 to 20 degrees of knee flexion, patella alta may be present.
