- See: Patella Alta:

- Discussion:
    - patellar height in relation to the joint line: (2 methods)
          - Insall and Salvati Method
          - Blackburne and Peel Method
         
    - fat density zone seen posterior to the quadriceps (water density) represents suprapatellar fat pad;
          - fat pad will be displaced anteriorly with joint effusion;
    - fabella:
          - sesamoid bone embedded in lateral head of gastroc muscle;
          - seen in about 10% to 20% of individuals;
    - technique:
         - pt lies flat on the affected side with the knee flexed 25-30 deg;
         - central beam is directed toward the medial aspect of knee joint w/ 5-7 degrees of cephalic tilt