(English captions by Trisha Paul from the University of Michigan)
With the patient supine, the leg can be fully extended to assess better for
joint effusion.
Compress the suprapatellar pouch, pushing the contents distally, and assess for
increased fluid.
Patellar ballottement can also be performed by compressing the patella and releasing
quickly. Observe for rapid rebound, which also indicates increased fluid pressure.
If a quicker tap is felt, a larger fusion is present, also called the ballottable
patella.