Knee and patella

Patient and part

For the AP knee, the patient is supine with the leg extended and rotated about 3 to 5 degrees internally so the epicondyles are parallel to the IR. For the lateral knee, the patient lies on the affected side with the knee flexed 20 to 30 degrees and the epicondyles perpendicular to the IR. More flexion pulls the patella into the intercondylar sulcus and closes the patellofemoral space. For the AP obliques, rotate the leg 45 degrees medially or laterally. For the PA axial intercondylar fossa, Camp-Coventry is prone with the knee flexed 40 to 50 degrees, and Holmblad is kneeling, leaning forward 20 to 30 degrees. For the tangential patella, Merchant is supine with both knees flexed about 40 degrees, and Settegast is prone with the knee flexed at least 90 degrees.