"orientation "
"SID"
"The fibula head is a great indication of rotation, if the fibula head is entirely superimposed, the image is not AP; to correct this you must internally rotate until the knee is in even contact with the image detector."
"Very slim patients may require a slight caudal angle to better visualise the joint space in an AP fashion. The opposite applies for larger patients (thicker thighs mean the leg may be naturally flexed at rest) and would require a slight cephalic angle. Whether cephalic or caudal, an angle of approximately 5-8° is adequate."
"The fibula head is a great indication of rotation, if the fibula head is entirely superimposed, the image is not AP; to correct this you must internally rotate until the knee is in even contact with the image detector."